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Protaional Paper No. 47

Series 0, Systematic Geology and Paleontology, 76

Department Of The Interior

United States Geological Survey

CHARLE8 D. WALCOTT, Director

The

Tertiary And Quaternary Pectens

Of California

By

RLPII ARNOLr)

Washington

Government Printing Office

r

Contents And Illustrations.

Introduction

Part I. The Tertiary and Pleistocene Formations of California

Po8t-Cretaceou8 geolojc column ".

Po8t-Cretaceou8 correlation table

Eocene

Martinez formation

Type locality

Name and de8C!ription

Definition

Localities

Fauna

Pecten fauna

Li8t of Martinez formation (lower Eocene) fossils.

Tejon formation

Type locality

Name and description

Definition

Localities

Fauna

Pecten fauna

List of Tejon formation ( Eocene) fossils

Oligocene

San Lorenzo formation

Type locality

Definition

Localities

Fauna

Pecten fauna

List of San Lorenzo formation (Oligocene) fossils. Miocene

Vaqueros sandstone

Type locality

Name and deijcription

Definition

Localities

Fauna

Pecten fauna

List of Vaqueros sandstone (lower Miocene) fossils. Monterey shale

Type locality

Name and description

Definition

Localities

Page.

4 Contents And Illustrations.

Part I. The Tertiary and Pleistocene Formations of — Continued. Miocene — Continued.

Monterey shale — Continued. PRe.

Fauna 21

Pecten fauna 21

List of Monterey shale ( middle Miocene ) fossils 21

List of fossils from the Carrizo Creek beds (Miocene) 22

San Pablo formation 22

locality 22

Name and description 22

Definition 22

Localities 22

Fauna 23

Pecten fauna 23

List of San Pablo formation (upper Miocene) fossils 23

List of Santa Margarita formation San Pablo) fossils from Salinas

Valley and southward 24

Pliocene. 25

Purisima formation 25

Type locality 25

Name and description 25

Definition 25

Localities 26

Fauna 26

Pecten fauna 26

List of Purisima fonnation ( lower Pliocene) fossils 27

List of San Diejfo formation fossils. . '. 28

Merced formation 28

Type locality 28

Name and description 28

Localities 29

Fauna 29

Pecten fauna 29

List of Merced formation (upper Pliocene) fossils 30

List of Pliocene fossils from Deadman Island 30

Pleistocene 31

San Pedro formation 32

Type locality 32

Name and description 32

Definition 32

Localities 32

Fauna 33

Pecten fauna 33

List of San Pedro formation ( Pleistocene) fossils

Geologic range of the California Pectens 37

Smnmary of the range of species and varieties 40

Part IL Synopsis and Descriptions of SrHOENKRA and Speciks 41

Synopsis of subgenera 41

Summary of the subgenera and species 44

Descriptions of subgenera and species 45

Genus Pecten Miiller 45

Subgenus Pecten s. s. Miiller 48

Subgenus Patinopecten Dall 48

Subgenus Dall 49

Contents And Illustrations. 5

Part II. Synopsis and Descriptions of Subgenera and Species — Continued. Descriptions of subjzenera and species — Continued.

Genus Pecten Miiller — Continued.. Vge,

Subnus Chlamys Bolten 49

Subgenus Lyropecten Conrad 49

Subnus iEqui|>eaten Fischer 49

Subgenus Plagioctenium Dall 60

Subgenus Pseudamusinm H. and A. Adams 50

Subgenus Amusium Bolten 50

Subgenus Propeamusium Gregorio 50

Subgenus Hinnites Def ranee , 50

Eocene Pectens 51

Oligocene Pectens 54

Miocene Pectens 59

Pliocene Pectens 94

Pleistocene Pectens 127

Recent Pectens 134

Unidentifiable Pectens 141

Bibliography 142

Plates 147

Index 251

Plate I. Sketch map of California, showing the principal fossiliferous Tertiary localities 7 II. Pecten calkinsi n. sp., P. landesi n. sp., P. proavus n. sp., and P. interradiatus

Gabb 149

III. Pecten clallamerjais n. sp., P. waylandi n. sp., P. pe(;khami Gabb, P. branneri

n. sp., and P. sanctiecruzensis n. sp 151

IV. Pecten carrizoensis n. sp. and P. coaliugaensis n. sp 153

V. Pecten keep n. sp., P. dilleri Dall, and P. eespeensis var. hydei n. var 155

VI. Pecten keep n. sp. and P. cooeensis Shumard 157

VII. Pecten propatulus and P. coosensis Shuinarti 159

VIII. Pecten oweni n. sp. and P. sespeensis n. sp 161

IX. Pecten propatulus Conrad 103

X. Pecten fncamis Dall and P. watts var. moran n. var 165

XL Pecten watt*ii n. sp., P. handing n. sp., P. nutteri n. sp., and I*, cr&ssicanlo

Conrad var. hamiltoni n. var 167

XII. Pecten n. sp 169

XIII. Pecten bowers n. sp 171

XIV. Pecten perrini n. sp 173

XV. Pecten perrini n. sp. and P. neahensis n. sp 175

XVI. Pecten crassicardo Conrad 177

XVII. Pecten crassicardo Conrad 179

X VIII. Pecten cra.ssicardo Conrad 181

XIX. Pecten estrellanus Conrad 183

XX. Pecten astrellanus and P. estrellanus Conrad var. catalinje n. var 185

XXI. Pecten estrellanus Conrad 187

XXII. Pecten niiguelensis n. sp 189

XXIII. Pecten miguelensis n. sp., P. estrellanus Conrad var. terminus n. var., P. vaughani

n. sp., P. stanfoniensis n. sp., and P. loinpicoensis n. sp 191

XXIV. Pecten magnolia Conrad 193

XXV. Pecten magnolia Conrad, P. cerrosennis Gabb var. mendenhalli n. var., ami P.

eldridgei n. sp 195

6 Contents And Illustrations.

Page. Plate XX VL Pecten deserti Conrad, P. andereoni n. sp.and P. andereoni var. barkerianos

n.var 197

XXVII. Pecten discus Conrad, P. pabloensis Conrad, and P. lompieoenwH n. sp 199

XXVIII. Pecten lompocensis n. sp. and P. Trask 201

XXIX. Pecten (Hinnites) giganteus Gray 203

XXX. Pecten merriami n. sp 205

XXXI. Pecten lUus Conrad 207

XXXIL Pecten stearnsii Dall 209

XXXIII. Pecten vogdesi n. sp., P. auburyi n. p., P. hemphilli Dall, and P. lecontein. sp. 211

XXXIV. Pecten vogdesi n. sp., P. auburyi n.Hi>., P. purisimaensis n. np., and P. tumeri

n.sp 213

XXXV. Pecten purisimaensis n. sp. and P. turneri n. sp 215

XXXVI. Pecten healeyi n. sp 217

XXXVIL Pecten healeyi n. sp 219

XXXVIII. Pecten caurinua Gould 221

XXXIX. Pecten caurinus Gould and P. paucicostatus Carpenter 223

XL. Pecten veatchii Gabb 225

XLI. Pecten parmeleei Dall, P. opuntia Dall, P. n.sp., P. ha.<tatus Sowerby,

and P. bellilamellatus n. sp 227

XLII. Pecten hastatus Sowerby and P. circularis Sowerby 229

XLIII. Pecten hastatus Sowerby var. navanrhud Dall, P. hastiitus Sowerby var. hindsii

and P. hastatus Sowerby var. hericius Gould 231

XLIV. Pecten jonlani Arnold, P. hastatus Sowerby var. strategus Dall, P. cerrosensis

Gabb, P. circularis Sowerby, and P. ri versi n. sp 233

XLV. Petten islandicus Muller, P. washburnei n. sp., and P. lawson n, sp 2;

XL VI. Pecten excavatus Anton, P. latiauritus Conrad, P. latiauritus Conrad var. nionotimeris Conrad, P. latiauritus Conrad var. cerritensis n. var. , P. latiauritus Conrad

var. fucicolus Dall, and P. latiauritus Conrad var. delosi n. var 237

XLVIL Pecten ashley n. sp ! 239

XLVIII Pecten ashley n. sp., P. raudolphi Dall, and P. randolph Dall var. tillamookensis

n. var 241

XLIX. Pecten cerrosensis (labb and P. cooperi n. sp 243

L. Pecten circularis Sowerby var. tequisulcatus Carpenter, P. pahneri Dall, and P.

davidsoni Dall 245

LI. Pecten diegensis Dall 247

LII. Pecten subnodosus Sowerby, P. hastatus Sowerby var. albidus Dall n. var., and

P. vancouverensis Whiteaves 249

LIII. Pecten subnodosus Sowerby and P. alaskensis Dall 251

Fig. 1. Pecten circularis Sowerby var. Carpenter; right valve, exterior ... 45

2. The same; right valve, interior 46

US-GCOLOGICAl. SURVEY

PROFESSIONAL PAPER NO. 4-7 Pll

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PLKISTurKNE ALITIKS

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The Tertiary And Quaternary Pectens Of California.

Bv Ralph Arnold.

This paper consists of two parts. The first is a brief outline of the different Tertiary and Pleistocene formations of California, giving the type localities, where, when, and by whom first descrited, their salient characters, where they and their supposed e([uivalents are known to occur, the species of Peeten found in them, and their typical fauna as far as known. The second is devoted to the description and illustration of all of the known Tertiary, Pleistocene, and Recent Pectens of the western coast of North America from Alaska to and including the Gulf of California. With the description of each species is also given an account of its geologic and geographic and, where practicable, its associated fauna.

This particular genus was chosen for study because of its great value for the stratigraphic determination of the Tertiary formations of the west coast and because of the large amount of material available at the time the work was undertaken. The genus is admirably adapted to purposes of correlation because of (a) its occurrence in every important Tertiary horizon in California, (i) the limited vertical and wide geographic range of most of its species, and (c) the comparatively simple yet salient characters which mark the different species.

The present paper is a larger and more comprehensive one than was contemplated when the work was first begun. The original plan was simply to monograph only the fossil Pectens of California, but as the work progressed it soon became apparent that the original subject could be thoroughly treated onh by a more or less detailed consideration of the fossil Pectens of the adjacent territory and the living members of the genus found along the whole western coast of North America. To give the paper its greatest possible value, it became necessary to define as accurately as possible the stratigraphic and geographic range of each species; and in order to do this consistently an examination of all of the available marine Tertiary imleontologic material from the west coast was undertaken. Then, that the data thus obtained might made more available and that the relations of the different faunas and horizons of the California Tertiary might be the more clearly set forth, it was deemed advisable to include a brief outline of the characteristics, geographic range, and faunas of the different Tertiary formations.

It was obvious that any scheme of classification of the Pectinidx based wholly upon specimens from the Pacific coast would necessarily be disconnected and unsatisfactory. It seemed advisable, therefore, to adopt some system which was founded

8 Tertiary And Quaternary Pecten8 Of California.

upon material from a much widen geographic range. Doctor DalPs classification of the family, given in his "Tertiary Fauna of Florida," not only fulfilled this requirement, but had the added desirability of being based partly upon a considerable amount of west coast Tertiary and living material. DalFs classification, with but slight alteration, has, therefore, been adopted for this paper.

Collections belonging to the following institutions and individuals were exam, ined by the writer during the preparation of this report:

United States Geological Survey, Washington.

United States National Museum, Washington.

Leland Stanford Junior University, California.

University of California, Berkeley.

California Academy of Sciences, San Francisco.

California State Mining Bureau, San Francisco.

Academy of Natural Sciences, Philadelphia.

American Museum of Natural History, New York.

State Museum, Albany, N. Y.

Mrs. T. S. Oldroyd, Long Beach, Cal.

Mrs. M. B. Williamson, Los Angeles, Cal.

Miss L. J. F. Hetrox, Santa Cruz, Cal.

Mrs. Blanche Trask, Avalon, Iw Angeles County, Cal.

Mr. F. L. Button, Oakland, Cal.

Dr. J. J. Rivers, Santa Monica, Cal.

Mr. J. Howard Wilson, Y'bonkers, N. Y.

Dr. Stephen Bowers, Ixm? Angeles, Cal.

Dr. I-. G. Yates, Santa Barbara, Cal.

Mr. Clark Smith, Paso Robles, Cal.

Mr. Delos Arnold, Pasadena, Cal.

The writer is indebted to Dr. Wm. H. Dall, of the United States Geological Survey, for kindly assistance and helpful suggestions given during the preparation of this paper. In addition to those already mentioned, the writer wishes to extend his thanks to the following for assistance and courtesies extended: Dr. J. C. Branner, Dr. J. P. Smith, Dr. J. C. Merriam, Dr. T. W. Stanton, Mr. Edward Hoitt Nutter, Prof. J. M. Hyde, Mr. G. H. Eldridge, Mr. Homer Hamlin, Dr. T. Wayland Vaughan, Dr. Paul Bartsch, Mr. L. M. Loomis, Mr. F. M. Anderson, Mr. Lewis E. Aubury, Dr. H. \V. Fairbanks, Dr. H. A. Pilsbry, Mr. C. W. Johnson, and many others.

The illustrations are, with the exceptions noted in the explanations, half-tone reproductions of retouched photographs. To give an even color effect, the Williams process of coating the specimen was used on most of the specimens before photographing. My acknowledgments and thanks are due to Miss M. K. Sumner, Miss Maude Baggett, Miss Marian Page, and Mr. H. C. Hunter, artists; to Mr. E. M. Bane, photographer; and to Messrs. J. L. Ridgway and N. W. Carkhuff, chiefs, respectively, of the sections of illustrations and photography, for the very satisfactory execution of the drawings.

Part I.

Tertiary And Pleistocene Formations Of California.

San Pedro, 1,000' 4-.

Merced. S.OOC ±.

Post-Cretaceous Geologic Column.

The process of marine sedimentation has been going on at one place or another within the California province almost without interruption since the beginning of the Cretaceous, and as a result the greater portion of this long period is represented by formations which outcrop over much of the territory between the Sierra Nevada mountain range and the Pacific Ocean. The onh great break in the record, as shown by the faunas of the different formations, is that between the Tejon (Eocene) and' its overlying beds. Each of the other formations is more or less closely related faunally to those immediately above or below, where the formations are of a more or less similar lithologic character.

The stratigraphic relations between adjacent formations vary in different localities. At one place two formations may be separated by a marked unconformity, while at another locality, only a comparatively short distance away from the first, the same formations may rest in an apparently conformable position with relation to each other. In general, however, the relations existing between the different formations is that indicated by the accompanying diagram of the California post- Cretaceous column.

Post-Cretaceous Correlation Table.

The following correlation table of the principal marine Tertiary and Pleistocene fonnations of California, together with a brief outline of the t3pical ones, is tentative and based on the information at hand at the beginning of 1906. Further study will doubtless add many new formations to the list, some of -which may represent horizons different from those of the known divisions, but the relative position of those already known is probably about as indicated in the table.

The faunal lists given under each formation comprise the species found at the t\'pe locality of the formation, and, in addition, such other species as are found in beds which have been quite definitely correlated with the latter. These correlations are necessarih' very broad and are intended only to indicate in a general way the contemporaneity of the strata in question.

Purisima, 800' ±.

San Pablo, 1,500-2,000'. '

Monterey, 2,500' ±.

Vaqueros, 3.000' ±.

San Ixreno, 2,300' ±.

Tejon, 4,000' +.

Chico (CretaceouH).

The Tertiary a,nd Pleistocene column of California.

The names used in the lists of fossils are those Total thickness 21,000 feet +.

,, . .11 Note. -Full lines repre-

commonly applied to the respective species by the west coast sent unconformity; broken paleontologists. Owing to the imperfect state of our knowledge conformity. regarding the nomenclature of the California Tertiary fauna, there is a probability

Tertiary And Quaternary Pecten8 Of California.

that some of the names used are erroneous. The writer, therefore, reserves the privilege of revising any of the names should future study warrant it.

A tentative correlation table of the principal marine Tertiary and Pleistocene foinnati&ns of California to 1906.

Epoch.

Pleistocene.

Oregon and Washington.

Northern and Central Salinas and Southern California. San Joaquin valleys.

Coos conglomer

(Merced fonnation. i Pao Ro))les foniia- I tion. Wildca

ir'wildcat forma- Mytilushed.f 'I tion."

Pliocene.

Transitional.

Miocene.

Sooke beds."

Purisima formation. I Cholame V a 1 1 e v ' hedH.

I San Pablo fonna- fPismo formation.

Astoria sandstone.

I Santa Marjjarita fonnation.

Southern California.

San Pedro formation.

Deadman Inland Pliocene.

San Diego formation.

Catalina Mioiene.

Contra Costa County Miocene.

Monterey shale.

Monterey shale.

Carrizo Creek beds (?)

' Monterey shale.

Vaqueros sand- Vaqueros Pasadena Miotene. stone. I i'tone.

Oligocene.

Eocene.

Tunnel Point beds."

Astoria shales. "

Aturia bed.

San forma- i tion. i

Arago formation." Tejon formation. Puget group. Martinez formation.

Tejon formation.

Tejon formation. ('reek

aDall, \V. H., North Am. Tertiary- horizons: Eighteenth Ann. Ropt. U. S. Geol. Survey, 1898, pt. 2, pp. 323-IM3. Note.— The author disclaims responsibility for those names in the above table which he does not discuss in this paper.

Eocene.

At least two hoi'izons are recognizable in the Eocene of the west coast, viz, the Martinez and the Tejon; and there may also possibly be a third, which is represented the richly fossiliferous beds exposed in the vicinity of Little Falls, Lewis County, Wash. The last-mentioned horizon is probabl} above that of the Tejon, although its relative position has not as yet been carefully worked out. On account of the lack of definite information concerning the affiliations of its fauna, the Little Falls beds will be included in the Tejon. The separation of the Martinez and Tejon formations is based principally upon paleontologic evidence, there being no apparent unconformity between them, although their lithologic characters are usually somewhat different.

Eocene Formations. 11

Martiskz Formation, Type Locality.

The type locality is south of the town of Martinez, Contra Costa County, Cal.

Name And Description.

This formation was named and described by J. D. Whitney in California Geological Survey, Paleontology, vol. 2, 1869, preface, p. xiii.

Definition.

Dr. J. C. Merriam, in his paper on "The geologic relations of the Martinez group of California at the typical locality,"" gives the following definition of the Martinez formation, which is generally accepted paleontologists and geologists:

'The Martinez group, comprising in the typical locality between 1,000 and 2,000 feet of sandstones, shales, and glauconitic sands, forms the lower part of a presumably conformable series, the upper portion of which is formed by the Tejon. It contains a known fauna of over sixty species, of which the greater portion is peculiar to itself. A number of its species range up into the Tejon, and a very few long-lived forms are known to occur also in the Chico ((cretaceous). Since the Martinez and Chico are faunal only distantly related, it is probable that an unconformity exists between them. Though satisfactory correlation of California formations with the suMi visions of the standard geological scale can be accomplished only when the local scale is fully worked out, we may, for the present at least, accept Mr. Stanton's correlation of the Martinez with a portion of the Eocene."

Localities.

Martinez, Clayton, Paclieco, and Army Point (near Benicia), Contra CoHta County.

Lower Lake, lke County.

Between heaciwaters of Pescadero Creek and San Lorenzo River, San Mateo County (?).

Rock Creek, Los Angeles County.

Point Loma, San Diego County (Eocene here may include the Martinez).

Fauna.

Pecten fauna. —The Pecten fauna of this horizon consists, so far as known, of only one species, jrroavu n. sp., and this from a locality of doubtful Martinez age.

".iour. lieol., vol. o. p. 775.

Tebtiary And Quaternary Pecten8 Of California.

The fauna of the Martinez consists essentially of the following species:

List of Martinez formation {loiver Eoceite) fools.<

[Those species followed by (L) arc found in the lower beds at Martinez; those by (U), upper beds at Martinez; those by (B), bedf> at Benicia; those by (C), beds at Lower Lake; and those by (P) outcrop on ridge between headwaters of San Lorenzo River and Pescadero Creek, San Mateo County.]

Fokaminifeka.

Forauiinifera nummuloid (U). Foraminifera, 3 sp. indet (L).

Anthozoa.

FlalUum remondianum Gabb (LBC). Trochocyathus zitteli Vaughan (L).

Bchinoidea.

Cidarie (?) spines (P). Schizaster lecontei Merriam (LU).

Brachiopoda.

Terebratiilina tejonensis Stanton (BCP). Terebratula (?) n. sp. (P).

Pelbcypoda.

Area biloba Weaver (LU). Cardium cooperi Gabb (LU). Crafisatellites unioides Stanton (C). Cuculltea niathewsonii Gabb (LUBC). Glycymeris veatchii Gabbvar. major Stanton (C). Leda alseformia Gabb (BC). Leda gabbi Conrad (LUC). Lima multiradiata Gabb (C). Meretrix sp. (LB). Modiolus merriami Weaver (LU). Modiolus ornatus Gabb (UC). Nucula tnmcata Gabb (LUB). Ostrea (cf.) idriaensis Gabb (P). Pecten proavus n. sp. (P). Phacoides tumeri Stanton (C). Pholadomya nasuta Gabb (LUB). Plicatula ostreiformis Stanton (C). Semele (?) n. sp. (P). Solen parallelus Gabb (C). Solen stantoni Weaver (U). Tapes (aff.) quadrata Gabb (LB). Tellina equalis Gabb (C). Tellina hoffmanniana Gabb (C). Tellina martinezensis (LU). Tellina honiii Gabb (UC). Tellina undulifera Gabb (UB). Teredo sp. (L).

Thracia karquinesensis Weaver (U). Venericardia planicosta Lamarck var. hornii Gabb (U).

a Compiled from lists by Merriam, J. C, Jour, (ieol., vol. 5, 1897, p. 773; Stanton, T. \V., Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 1, 1896, p. 1025; and Weaver, C. E., Bull. Dept. Geol., Univ. of Cal., vol. 4, 1905, No. 6, pp. 110-111.

Actieon lawson Weaver (LB). Ampullina (cf.) striata Gabb (UBC). Architectonica tuberculata Weaver (U). Brachysphingufl liratus Gabb (UBC). Bull inula subglobosa Weaver (U). Cerithiopsis alternata Gabb (C). Cylichna costata Gabb (LC). Dentalium cooperi Gabb (LUC). Dentalium stramineum Gabb (U). Discohelix califomicus Weaver (L). Ficopsis angulatus Weaver (U). Fusus aequilateralis Weaver (L). Galerus excentricus Gabb (C). Helcion (cf.) dichotoma Gabb (P). Heteroterma gabbi Stanton (UC). Heteroterma striata Stanton (C). Heteroterma trochoidea Gabb (U). Heteroterma, indet. (U). Lunatia hornii Gabb (C). Megatabennus (?) n. sp. (P). Megistostoma striata Gabb ( U. ) Morio tuberculatus Gabb (U). Natica sp.

Neptunea mucronata Gabb (L). Perissolax blakei Conrad (B). Perissolax tricamatus Weaver (LUBO). Serpula (?) sp. (LP). Siphonalia lineata Stanton (LUC). Strepsidura pachecoensis Stanton (U). Tritonium (cf. ) californicum Gabb (P). Tritonium eocenicum Weaver (U). Tritonium impressum Weaver (U). Tritonium pulchrum Weaver (U). Turbinella crassitesta Gabb (L). Turritella conica Weaver (U). Turritella infragranulata Gabb (UBC). Turritella martinezensis Gabb (L). Turritella pachecoensis Stanton (U). Turris sp. indet. (U). Urosyca caudata Gabb (LUBC). Urosyca robusta Weaver (L). Xenophora zitteli Weaver (L).

('Ru8Tacka.

Cancer (U).

Crustacean remain, inacruran (U).

Eocene Formations. 13

Tejon Formation, Type Locality.

The type localit} is in the region about Fort Tejon, Kern County, Cal.

Name And Description.

This formation was named and described by J. D. Whitney in California Geological Survey, Paleontology, vol. 2, 1869, preface, p. xiii.

Definition.

The original definition and description of this formation is as follows:

The Tejon group the division B of Paleontology, volume 1, is peculiar to California. It is found most extensively developed in the vicinity of Fort Tejon and about Martinez. From the latter locality it forms an almost continuous belt in the Coast Ranges to Marshs, 15 miles east of Mount Diablo, where it sinks under the San Joaquin plain. It was also discovered by the different members of the Survey at various points on the eastern face of the same range as far south as New Idria, and in the summer of 1866 by Mr. Gabb in Mendocino County, near Round Valley, the latter locality being the most northern point at which it is as yet known.

"This group contains a large and highly characteristic series of fossils, the larger part peculiar to itself, while a considerable percentage is found extending below into the next group (Martinez)

Localities.

Fort Tejon, Uvas Pass, and San Emidio, Kern County.

Marysville fiuttes, Sutter County.

Merced Falls, Merced County.

Martinez, Somersville, Clayton, and Marsha, Contra Costa County.

New Idria and Griswold, San Benito County.

Coalinga and iSan Joaquin coal mines, Fresno County.

North side of Sisar Valley, Ventura County.

North side Santa Ana Mountains, 4 miles south and 5 miles northwest of Corona, Riverside

County. San Luis Rey to San Diego, Rose Canyon and Point Loma Peninsula, San Diego County. Peninsula of Ijwer California, latitude 29° 30'. Port Crescent, Clallam County; Little Falls, Lewis County, and Oakville, Chehalis County, Wash.

(Landes and Arnold).

In Oregon at the following loealitie.s, according to Diller (18fH>):

Nehalem River, 5 miles east of Nehalein, and also midway Jewell and Mishawaka.

Wilson River toll road, 22 miles from Tillamook.

Vineyard Hill, 4 miles north of Corvallis.

Benson's and Howe's, 5 miles north of Corvallis.

Scott's, and Newton's, southwest of Corvallis.

Roger's, in section 27, T. 13 S., R. 6 W.

Monroe, Comstock, Cleveland, Callahan's, and Camas, Douglas County.

Near mouth of Little River, 20 miles northeast of

Marshfield, Jordan Point, and Cape Arago, southward to near mouth of Coquille River.

Tertiary And Quaternary Pe0Ten8 Of California.

Fauna.

Pecten fauna. — The Pten fauna of the Tejon group consists, so far as known, only of three species, P, calkinsi n. sp., P, landesi n. sp., and P. interradiatus Gabb. The first two probably belong to the subgenus Chlmys but are not closely allied to any of the subsequent members of this group, so far as known. P, interradiatus belongs to the Propeamusium. group and appears to be the precursor of such forms as P, stanfordensis P, wayJmidi and P. clallamenms.

The following species have been found in the Tejon formation in dij9recent parts of California:

Lit of Tejon formaiioii (Eocene) fossils, [ThoRe marked with an asterisk (♦) have been found at the type locality.]

Anthozoa.

Flabellum califomicum Vaughan. Flabellum remondianum Gabb. Trochocyathus californicus Vaughan. Trochocyathus stantoni Vauglian. Trochocyathus stria tus Gab)).

Pelecypoda.

*Arca homi Gabl).

Astarte seniidentata Coojier.

*Axinea cor Gabb (=Glycymeris id.).

*Axinea sagittata Gabb ( =Glycymeri8 id. ).

Barbatia moreei Gabb.

*Cardiuin breweri Gabb.

*Cardiuin cooperi (iabb.

*Cardium (LievicArdium) linteum Conrad.

Corbula ala'formis Gabb.

*Corbula horni Gabb.

Corbula parilis Gabb.

Corbula primorsa Gabb.

*Crafi8satellites grandis Gabb.

*Crae8atelliteH uvasana Conrad.

Donax latuH Gabb.

*Do8inia elevata Gabb.

*Do8inia gyrata Gabb.

gabbi Conrad.

Lima multiradiata Gabb.

Luciua? cretacea Gabb.

*Meretrix califomica Conrad.

*Meretrix horni Gabb.

*Meretrix ovalis Gabb.

*Meretrix uvasana Conrad.

♦Modiolus omatus Gabb.

♦Mysia? polita Gabb.

*Mvtilu8 asia Gabb.

PBLECYPODA — continucd.

*Mytilu8 humerus Conrad.

*Nucula truncata Gabb.

Ostrea appreesa Gabb.

Ostrea idriatinsis Gabb.

*Septifer dichotomus Gabb.

Solen (Hypogella) diegoensis Gabb.

Stalagmium concentricum Gabb.

*Tapes conradiana (jabb.

Tapes? cretacea Gabb.

♦Tapes? quad rata Gabb.

*Tellina califomica Gabb.

♦Tellina horni Gabb.

*Tellina longa Gabb.

*Tellina rmondi Gabb.

Unio penultimus Gabb.

Venus lequilateralis (abb.

*Venerica,rdia planicosta Lamarck.

*Venericardia planicosta var. homie Gabb.

♦Acmfca tejonensis Gabb.

Amauropsis alocata Gabb.

Ancilla (Oliverato) califomica Cooper.

Ancilla elongata Gabb.

*Architectonica cognata Gabb.

♦Architectonica horni Gabb.

Bela clathrata Gabb.

Bittium longissimum Cooper.

Brachysphingus liratus Gabb.

Brachysphingus sinuatus Gabb.

♦Bulla homi Gabb.

♦Bullia (Molojphoms) striata Gabb.

Cancellaria irelaniana Cooper.

Cerithiopsis alteraata Gabb.

a Compiled from lists by Cooper, J. G., Seventh Ann, Rept. California State Mineralogist, p. 271 et seq.'. Cooper, J. G., Bull. California State Mining Bureau No, 4, p. 39 ei tfeq.; Stanton, T. W., Seventeenth Ann. Rept. U. 8. Geol. Survey., p. 1021 et seq.: Merriam, J. C, Jour. Geol., vol. 5, p. 771.

Oliqocene Formations.

List of Tejon formation (Eocene) fomh — Continued.

GASTEROPODA — continuecl.

*Conu8 homi Gabb. ♦Conufl rmondi Gabb. Cordiera gracillima Cooper. *Cordiera microptygma Gabb. *Cypr8ea (Luponia) bayerquei Gabb. Cypraea (Epona) mathewsoni Gabb. *Dentalium cooperi (labb. *Dentalium stramineuni Gabb. Diodus tenuis Gabb. Drillia ullreyana Cooper. *Enflpira alveata Conrad.

Fasciolaria io Gabb. Fasciolaria lieviusc'ula (iabb.

Fasciolaria sinuata Gabb. Ficopsis cooperi Gabb. *Ficopei8 homi Gabb. Ficopsis rmondi Gabl). *Fu8U8 califomicus Conrad. *Fu8U8 diaboli Gabb. *Fn8U8 martinez Gabb. Fusus supraplanus Cooper. Galerus excentricus Gabb. Gyrodes dowelli White. Loxotrema turrita Gabb. *Lunatia homi Gabb. *Lunatia nuciformis Gabb. Lunatia shumardiana Gabb. Mangilia saturalis Cooper. Margaritella crenulata Grabb. Megistostoma striatum Gabb. Mitra cretacea Gabb.

Mitra eimplicissima Cooper. *Morio (Sconsia) Gabb. Nassa antiquata Gabb. *Na8sa cretacea Gabb.

GASTEROPODA — continued.

*Natica uvasana Gabb.

*Naticina obliqua Gabb.

Neptunea (Tritonofusus) cretacea Gabb.

Neptunea?' gracilis Gabb.

Neptunea? supraplicata Gabb.

Nerita (Thelioetyla) triangulata Gabb.

Neverita globosa Gabb.

*Neverita secta Gabb.

*01ivella mathewsoni Gabb.

*Peri88olax blakei Conrad.

Pleurotoma perkinsiana Cooper.

Potamides Cooper.

Potamidcs? davisiana Cooper.

*Rimella canalifera Gabb.

Rimella simplex Gabb.

Scalaria (Opalia) mathewsoni Gabb.

iphonodentalium pusillum (rabb.

*8pirocrypta pileum Gabb.

*Surcula claytonensis Gabb.

Surcula crenatospira Cooper.

Surcula inconstans Cooper.

Surcula monilifera Cooper.

Surcula pneattenuata Gabb.

Surcula raricostata Gabb.

*Surcula sinuata Gabb.

Terebra califomica Gabb.

Terebra wattsiana Cooper.

*Tritonium ialifomicum Gabb.

Tritonium (Trachytriton) diegoensis Gabb.

*Tritonium (Trachytriton) fusi forme Gabb.

♦Tritonium homi Gabb.

♦Tritonium paucivaricatum Gabb.

♦Tritonium (Trachytriton) tejonensis Gabb.

♦Tritonium whitneyi Gabb.

Turritilla martinezensis Gabb.

Oliqocene.

The recognition of Oligocene strata on the western coast of North America has leen more or less uncertain. Doctor Dall " has recognized what he considers to be an Oligocene fauna from several localities in the northwestern part of Oregon, but as very little detailed paleontologic work has been done in that section no adequate lists of the fossils are available. Certain gray shales in the vicinity of Porter, Chehalis County, Wash., and shales near Bean Point, King County, and along the Strait of San Juan de Fuca, on the north side of Clallam County, in the same State, contain a fauna which may also be Oligocene.

aDIller. J. S., Seventeenth Ann. Kept. U. S. Geol. Suney, pt. 1, 1896, p. 464

16 Tebtiaby And Quaternary Pe0Ten8 Of California.

Within the last five years strata have been discovered in the Santa Cruz quadrangle which contain a fauna representing a horizon probably lower than any of the known lower Miocene horizons of California. The faunal relations and stratigraphic position of this new formation have led the writer to believe that it belongs in the Oligocene.

With the exceptions above noted, no marine Oligocene has heretofore been recognized on the west coast north of that found in the Central American States.

San Lorenzo Formation. Type Locality.

The type locality is on San Lorenzo River, 2i miles above the town of Boulder Creek, Santa Cruz County, Cal.

Definition.

The San Lorenzo formation consists essentially of a series of grayish "muddy" shales and tine sandstones, which are typically exposed along the bed of the San Lorenzo River, about 2 miles above Boulder Creek, Santa Cruz County. The formation extends westward from the type locality into the Big Basin, on the north side of which it rests conformably against the older yellowish sandstones (possibly Oligocene in age) of the Butano Ridge. To the southeast of the exposures on San Lorenzo River the formation, in the shape of a broad anticlinal nose, gradually dips conformably under the sandstones and conglomerates of the lower Miocene. The approximate thickness of the formation in the vicinity of the type locality is about 2,300 feet.

Localities.

San Lorenzo River, Boulder Creek, Kings Creek, Twobar Creek, Bear Creek, and Creek, all near the town of Boulder Creek, Santa Cruz County.

Fauna.

The fauna of the San Lorenzo formation consists, for the most part, of forms best suited by the conditions prevalent during the deposition of sandy shales. In other words, it is a moderately deep-water fauna. It shows several species found in the Monterey shale, but it also contains many species which appear to be closely related to Tejon (Eocene) forms. Bearing in mind these faunal relations and the stratigi-aphic position of the formation, it appears probable that it belongs in the Oligocene.

Pecteti fauna, — In this horizon we meet with the common Miocene Pseuda7nu8ium P. peckhami and characteristic representatives of Pecten s. s. and ChlamyH the groups which are so well represented in the later formations. P, {Pectet}) mnctpeeruzensis is quite (Josely allied' to P. hell's and P. which are found in the Pliocene, while in the top of the formation, associated with a transitional Oligocene-Miocene fauna, is P. (Chlamys) hranneri the analogue and probable precursor of P, islandicns, and the latter's related forms. P, clallamensia and P. vmylandi from the Oligocene-Miocene series of Washington should also probably be included in the Oligocene fauna.

Miocene Formations.

The following species have been found in the San Lorenzo foimation at the type locality, or within a radius of four or five miles from it:

List of San Lorenzo formation (Oligocene) fools. [Those marked with an asterisk (♦) have been found at the type locality.] BRACHiopoDA. PELECYPODA — Continued.

Terebratula cf. nitens Conrad.

Pelecypoda.

Area ep. A.

♦Callista angustifrons Conrad.

Callista sp. A.

Cardium (cf. ) breweri Gabb.

Cardium (Lsevicardium?) n. sp.

Corbula ep. A.

Cytherea (cf. ) vespertina Conrad.

Cytherea sp. A.

Leda, 3 sp., A, B, and C.

Macoma nasuta Conrad.

♦Macoma, 2 sp., A and B.

Modiolus (aff.) rectus Conrad.

Modiolus n. sp.?

Nesera (aff. ) pectinata Cpr.

*Nucula n. sp. A.

Nucula n. sp. A var.

Oetrea (cf . ) idriaensis Gabb.

Panopea (cf. ) generosa Gould.

Pecten peckhami Gabb.

Pecten sanctiecruzeneis n. sp.

Phacoides acutilineatus Conrad.

Phacoides (Myrtea?) n. sp.

Solemya ventricosa Conrad yo.?.

Solen n. sp. (aff. ) curtus Conrad.

*Tellina (cf.) arctata Conrad.

*Tellina (cf. ) oregonensis Conrad.

Thracia (aff.) trapezoides Conrad.

Thyasira n. sp.

Venus (cf.) lenticularis Gabb. Yoldia impressa Conrad.

Gasteropoda.

Actajon sp. A.

Astyris n. sp. A.

Bela clathrata Gabb.

Crepidula praerupta Conrad?.

*Cylichna (aff.) petrosa Conr. or horni Gabb.

Dental ium near substriatum Conr. or cooperi

(Tabb. *Dentalium n. sp. A. Dolium? n. sp.?. Fusus (cf.) mathewsonii Gabb. *Fu8US (cf.) oregonensis Conrad. Fu8UB (aff.) thracius Conrad. *Fusus, 3 n. sp., A, B, and C. Fusus or Perissolax sp. A. (lalerus excentricus (iabb.?. GaleruB (aff.) mammillaris Brod. *Lunatia (cf.) sbumardiana Gabb. Natica sp. A. Neverita saxea Conrad. *Pleurotonia (aff.) raricostata Gabb. Pleurotoma, 2 sp., A and B. Scala (Ojmlia) sp. A. Sigaretus scopulosus Conrad. Solarium (aff.) ainoenum Conrad.

Solarium n. sp. A.

Cephalopoda.

Aturia ziczac Sowerby (?).

Miocene.

Three divisions are commonly recognized in the Miocene of California, the lower (Vaqueros), middle (Monterey), and upper (San Pablo). At certain localities the relations existing between these three divisions are very clear, while at others they are obscure, and at still others it appears as if the lower two are interbedded with each other to a greater or less extent. In the vicinity of Mount Diablo, Doctor Merriam is able to differentiate a fourth division lying between the Monterey shale and the San Pablo, which he calls the Contra Costa County Miocene, and which is characterized, according to him," by ClypeaMer {\)hreireriauu8 Trochita costillata several new species of Jlodiofm, etc. This last horizon has not as yet been recognized outside of the Mount Diablo Kange.

" Merriam, 17260— No. 47—06—

. C. Bull. Dept. Geol. Univ. Cal.. vol. 3, No. 16. 1904. p. 378.

18 Tebtiary And Quateenaey Pecten8 Of Calibobnia.

Vaqueros Sandstone. Ttpe Locality.

The type locality is Los Vaqueros Valley, Monterey County, Cal.

Name And Description.

This fonnation name was suggested by Mr. Homer Hamlin and first used by Dr. H. W. Fairbanks in the descriptive text of the San Luis folio (California), 1904, p. 3.

Definition.

The Vaqueros sandstone lies conformably beneath the Monterey shale and rests conformably upon the San Lorenzo formation and unconformably upon the Tejon (Eocene) or older formations. It varies in thickness in different localities, its maximum being between 2,000 and 3,000 feet.

LOCALITIES. Martinez, Contra Costa County.

Mount Diablo Range in Contra Costa and Alameda counties. Santa Cruz Mountains, in San Mateo, Santa Clara, and Santa Cruz counties (Mindego Creek, Stevens

Creek, Boulder Creek, etc.). Los Vaqueros Valley and Santa Lucia Range, Monterey County. Lynchs Mountain, Corral de Piedra Creek, Hazzard Canyon, Morro Creek, La Panza, and Toro Creek

San Luis Obispo County. Barker's ranch (Kern River), Poso Creek, San Pmidio Canyon, 6 miles southeast of Annette, and

Avenal Canyon, Kern County. San Miguel Island and Santa Inez Mountains, Santa Barbara County. Ojai Valley, Sespe oil district, and Santa Monica Mountains, Ventura County. Santa Monica Mountains, Ple Rock Valley, and Pasadena, Los Angeles County. (This formation

may also be younger than the Vaqueros. ) Santa Ana Mountains and El Toro, Orange County. Carrizo Creek, San Diego County (?). (Probably younger than the Vaqueros.)

According to Merriam, the lower Miocene or Agnsmna zone occurs in Oregon, and the same horizon is probably represented still farther north by a part of the Oligocene-Miocene series of Washington.

Fauna.

The Vaqueros has a very characteristic fauna, consisting of numerous forms peculiar to itself besides many species found in the overlying formations. A few Vaqueros species are found in the transitional beds between it and the San Lorenzo (Oligocene), but none of the members of its fauna, so far as known reach into the Tejon (Eocene). On account of the occurrence of species of the peculiar genus Agaaoina in the lower Miocene, Doctor Merriam has given it the appropriate name "(/a;/?a zone." He has tentatively divided this into two stages; the probably lower of the two characterized by TwTitella hoffmanni and the upper Turritella ocoyana, Ko differentiation of the two stages is attempted in this paper.

Pecten fauna, — The Pect&n fauna of the Vaqueros sandstone or Agasoma zone is a large one and consists of the following species: P, ander%oni P, andersoni

a Bull. Dept. Geol. Univ. Cal., vol. 8, 1904, p. 878.

Miocene Formations.

var. harkerianu P, hmnet'sl Irrantieri crasicanht and its variety hamilton! P. {Ilhinites) glganteua P, estrellamts P, magnolia P, mlgiidensis P, peckham! P, perrini P, sespeemU and its variety hydei P, sanctiecruzensis and P, vaughanL

The following species are of uncertain stratigraphic standing; some or all of them may extiMul into the lower Miocene: P, carrizoeiisis P. cerronensU var. raendenhalU P, d4sert! P, fucanvs P, hmnlhii P. keep P, neafumsis P, it utter P. propatulm, and stanfordtmHi,

The following is the fauna (with the exception of Pecteri) found in the Vaqueros sandstone of central California:

Ij'iM of Vaqueroi* Mindstone {lower Mioi'ene) foHgih. [TImww* iiiHrkHi with an asterisk are supposed lo elmracteriHtic of this horizon.]

l-XIIINOIDKA.

Soutella fairbankni Merriam.

Brachiopoda.

*Terebratella (?) n. np., A.

Pelbc'Ypoda.

Angulus (cf. ) button Dall.

Area (cf.) canalis Connwl.

Area microdonta Conrad.

(*?)Canlium (Traehycardiuin) n. sp., A.

Chione suecincta Valenciennes (?).

*Chione nmthewHonii Gabb.

Chione n. sp., A (very large).

*Corbula (cf. ) evansiana Shumanl.

*Do8inia conradi (xabb.

*Do8inia niathewsonii Gabb.

Dosinia (cf.) montana Conrad.

Doninia (aff. ) ponderoea Gray.

*Glycynieri8 n. sp. A (very large).

la taphria Dall.

*Leda sp.?.

Macoma (cf. ) calcarta Giiielin.

Macoma nasuta Conrad.

Mactra californica Conrad (?).

Mytilns niathewsonii Gabb.

*OHtrea (aff.) titan Conrad.

Panopea generoea Gould?.

Pecten (see previous list).

*Periploina n. sp. A.

Phacoides acutilineatus Conrad.

Phacoides richthofeni Gabb.

*Pinua alamedensis Yates.

Psaniinobia Gabb.

Saxidonius Gabb.

Solen sicarius Gould.

Tapes truncata Gabb.

*Tellina n. sp. A (aff.) Inxiegensis Hinds.

Tellina sp.

*Tivela ineziana Conrad.

Venus pertenuis Gabb.

*Yoldia n. sp. A (aff. ) cooperi Gabb.

*Acmiea n. sp. A.

*Actieon n. sp. A.

*Aga8onia barkerianuni Cooper.

*Agasoma (cf. ) gravida Gabb.

*Agasoma kemianurn Cooper.

Astyris n. sp. (aff. ) tubero.sa Cpr.

*Calliostoma n. sp. B.

*Chlorostoma n. sp. A.

*Conu8 n. sp. A.

Crepiduia princeps Conrad.

*Cunia bipiicata Gabb.

*Dentalium n. sp., B.

*Fi88uridea n. sp., A.

*Fu8U8 sp. A.

Galerus (aff.) excentricus Gabb.

GaleriLs mammillaris Brod. (?)

Megatebennus biniaculatus Dall.

Naasa (cf. ) mendicii GouM.

*Natica ocoyana Conrad.

Neverita callosa Gabb.

*Ocinebra (aff.) lurida

Olivella

*Pynda (?) sp.

Sigaretus scopulosus ( jinrad.

*Solarium sp.

*Tritoniu!H sp.

Trochita Conrad (?)

Trophon (iabb.

*Turritella hoffnianni Gabb.

*Turritella ocoyana ( 'onrad.

*Turritella variata Conrad.

Balanus cstrellanus Connnl.

I'lSCKS.

*Galeocerdo product us Agassiz. Lamna clavata Agassiz. *Oxyrhina tumula Agassiz.

20 Tertiary And Quaternary Pectens Of California.

Monterey Shale. Type Locality.

The type locality is vicinity of Monterey, Monterey County, Cal.

NAME AND DES("RIPnON.

This formation was named and described by William P. Blake in Proceedings of the Academy of Natural Sciences of Philadelphia, vol. 7, 1866, pp. 328-331.

Definition.

In describing the shale beds in the vicinity' of Monterey Blake has the following to say regarding the stratigraphic relations: "This interesting formation, teeming with the skeletons of microscopic organisms, appears to overlie and to be conformable with the Tertiary strata that underlie a part of the town of Monterey and extend to and beyond the mission of San Carlos. These strata rest upon a porphyritic granite, which forms the projection of the coast called Point Pinos, and is the bulwark of the bay." The only fossils mentioned by Blake as occurring in the formation are: Tell ma co7ige8ta Conmd Lutraria trdskii Conrad, and diatoms belonging to the genus Coccinodicii,

The term ''Monterey shale," as now accepted, applies to the very characteristic shale formation typically developed in the Santa Lucia and Santa Cruz ranges. It sometimes attains a thickness of over 2,000 feet, and at some localities is interbedded with layers of sandstone or thin strata of a rather impure limestone. The formation is underlain conformably by the Vaqueros sandstone at most localities, but at a few it rests directly upon older rocks. In some places the line of demarcation })etween the Vaqueros and Monterey is very distinct, while at others the beds seem to merge into (ach other through a series of alternating sand and shale layers. As suggested by Doctor Lawson, the shale probably has an inshore equivalent of sandstone, whose fauna is doubtless entirely different from that of the shale and probably shows a marked resemblance to that of the underlying Vaqueros and overlying Contra Costa County Miocene. Following the deposition of the Monterey came the great upheaval along the coast which resulted in the elevation of the shales and their subsequent erosion. As a result of this a line of marked unconformity genemlly separates the Monterey from the overlying formations.

Ixxjalities.

Southeast of Pinole, Contra CoHta County.

Lanley Hill and Alpine clistrict, San County.

Castle Rock Ridge, Santa (/lara County.

Castle Rock Ridge, vi(;inity of Ben Ixjniond, Felton, (gibbs, and Santa Cruz, Santa Cruz County.

Monterey, Carmelo Valley, and Santa Lucia Range, Monterey County.

Big Panoche CnH*k to K njyenhagens, Fresno County.

Templeton, Atasciidero, (janyoii. Point Buchon to near mouth of Davis C'anyon, northeast of

Arroyo Grande, and other localities in San Luis Olnspo County. Northwest of Tulare Lake, Tulare County.

)

Miocene Formations. 21

McKittrick district, Kem County.

Ojai ranch and vicinity, Ventura County.

Santa Inez Mountains, Santa Barbara County.

San Pedro, Sa'nta Monica Mountains, and east of Los Angeles, Los Angeles County.

Fauna.

The fauna of the Monterey shale is quite limited, and the fossils are generally preserved only in the form of casts or molds. Pecien peckltami is one of the most abundant fossils, but as it is not confined to the Monterey its value as an agent of correlation is only nominal. The most characteristic species appear to be Area ititrntereyarui and a large, coarse-sculptured Leda.

Pecteri fauna. — The Pecteii fauna of the Monterey (including such species as are found both below and above it, or in its included sandstones, but which, on account of habitat, are not found in the typical shale) is as follows: P. andersoniy P, cramicardo P. eatrellanus P. {IllnnUes) ijiganteus P, pedroamis and P, peckhxiniL

The following species have a more or less uncertain stmtigmphic status, and some or all of them may extend into or through the Monterey or its equivalents: P, howertii P, cerrosensls var. menden/ialli P, discus P. ftwann P, Jceepl, IvinpicoeimH P. neahensU,, P, natter P, perrun P, propatxdm and P, stanJardetiMts.

The following species have been found in the Monterey shale near the type locality or in the Santa Cruz Mountains, just to the north and across Monterey Bay from it.

List of Monterey nhale {middle Mioreiie) fossils. [Those marked with an asterisk are supposed to be charaeteristie.]

PELECYPODA. i PELECYPODA — COntlnUed.

Area montereyana Oamont. ' Pecten andersoni n. Hp. Callista angustifrons Conrad. Pecten ( iabl). Chione niathewsonii (labb. ' PhacoMet* like crenulata. ♦Corbulasp., probably new. , Saxidoimis sp. Cytherea np. A. ' *Seniele n. sp. A. *Diplodonta n. sp. (aff. ) serricata Reeve. , Siliqua sp. *Glycymeris (?) n. sp. *Leda n. sp. A. n. sp. B.

Lutraria traskii Conrad.

*Tellina congesta Conrad.

Gasteropoda.

Cylichna (cf. ) petrosa Conrad.

The fauna of the Carrizo Oeek beds, which are undoubtedh' Miocene but of uncertain horizon, belongs to an entirely separate biologic province from that of the principal California Miocene, and for that reason has few species in common with any of the other known California deposits. The following is a list of the fossils so far recognized from the Carrizo Creek beds. (See also list of fossils from Santa Rosalia, Lower California, under Pecten cerroserisi var. inendenhalUy p. 85.)

Tertiary And Quaternary Pectens Of California.

List of fossils from the Carrizo Creek beds (Miocene).

Anthozoa.

Diploria bowers Vaughan (Mss.)* Favia merriami Vaughan. Pleeiastrea calif ornica Vaughan (Mas.). Siderastrea californica Vaughan (Mss.)- Stephanocoenia fairbanksi Vaughan. Stephanocoenia fairbanksi var. columnaris Vaughan.

Echinoidea.

Clypeaster bowers Merriaui.

Pelecypoda.

Anomia subcostata Conrad.

Area n. sp. (?) A.

Cardium (Trachycardium) n. sp. (aff.) quadrige-

narium Conrad. Doeinia sp., perhaps new. Gastrochana sp. Lithophaga sp.

PELECYPODA — Continued.

Ostrea vespertina Conrad.

Pecten carrizoensis n. sp.

Pecten crrosensis var. mendenhalli n. var.

Pecten deserti Conrad.

Pecten (Hinnites) giganteus Gray.

Pecten keep n. sp.

Phacoides (cf. ) acutilineatus Conrad.

Pholas (aff. ) crucigera Sowerby.

Cypnea sp. indet., large and probably new. Malea ( -f-Dolium ) near ringens Sowerby. Oliva (?) sp. indet.

Polynices (Neverita) recluziana Deshayes. Stronibus n. sp. (aff.) granulatus Sowerby. Strombus (?) n. sp. B. Tivela (cf.) ineziana Conrad. Turritella (cf.) hoffmanni Gabb.

San Pablo Formation.

Type Locality.

The type locality is south side of San Pablo Bay, near Union oil refinery. Contra Costa County, Cal.

Name And Description.

The formation was named and described by Dr. J. C. Merriam, in Bulletin of the Department of Geology, University of California, vol. 2, No. 4, 1898, p. 113 ef seq.

Definition.

The formation at the type locality consists of a series of sandstones, tuffs, and ashes with an approximate total thickness of between 1,500 and 2,000 feet. At this locality it rests apparently conformably upon the Contra Costa Count}' Miocene. In the Salinas Valley, and at many other places, formations which are probably the equivalents of the San Pablo rest unconformably upon the Monterey shale. In the Santa Cruz quadrangle, beds containing the supposedly' characteristic San Pablo echinoderm, Astrodap&is tumidns R6mond, rest unconformably upon the Monterey, and are overlain conformably by at least a part of the Purisima (lower Pliocene).

Localities.

San Pablo Bay, Walnut Creek, and Kirkers Contra Costa County.

Scott Valley, Santa Cruz County.

San Ardo and other localities in the Salinas and adjacent valleys, Monterey County.

Coalinga and vicinity, Fresno County.

Eetrella Valley, Santa Margarita and vicinity, 3 miles east of La Panza, Caramatta ranch. Music P. 0.,

and Pismo and vicinity, San Luis Obispo County. Santa Catalina Island, Los Angeles County.

Miocene Formations.

Fauna.

Doctor Merriam, in his original definition of the San Pablo formation, says:" 'The series of strata characterized by the presence of AstrodupslH and Scutella {Chjptastei) (jahhi may, with reference to its more important features, be treated as a distinct formation, and will be referred to in this paper as the San Pablo foiTuation." By definition, therefore, the formation is limited in a general way to the zones of the above-mentioned echinoderms. In most of the localities where the formation has been recognized, at least one of these forms has generally been detected. Ostrea titan Tainhmnna grtyarla pHeudtxardiuin gahhi Choriw helclwri a small Ocinelyra and several species of Pecteii are also commonly found in its fauna.

According to Merriam the fauna of the San Pablo is known so far by about fifty species, of which nearh one-third are peculiar to this formation, about onefourth are known also from the Contra Costa Count}- Miocene, and one-sixth from the Merced; while of the total number a little less than one-half are extinct. The writer has noted several San Pablo species extending down into the Vaqueros (lower Miocene); while his estimate of the extinct species is about 65 per cent, i-ather than a little less than 50 per cent as given by Merriam.

Pecten fauna, — The Pectin fauna of the San Pablo, and its supposed equivalents in age, consists of the following species: PeeUn andersfmi, P. eooseiiis P, crasalcardo and its variety hanultoul P, discus P. eldridgt! eatTellanua and vars. catallm and tennirms P, {Illnnltes) gigantem P. hastatuH var. herlciuH P, iitctteri P, mven! P, pabUicnMH P. pedroanuH,

The following species of more or uncertain sttitus may occur in the San Pablo or its equivalents: P, carrizoeiistH P, cerronenU var. nietdenhalU P, dillen P, fucanus keep P, neaheiuiii P, jyropatulim.

The following fossils have been found in the San Pablo formation at San Pablo Bay, Kirker Pass, and other localities in the Mount Diablo region.

of Snn Pahlo formation [upper Miocene) foHinU J'

[Those markiHl with un asterisk have been found by the writer it the type locality: those followed by (C) are siipiKixed to be oharaeteristio. and those followed by ( I) also occur in the recent fauna of the coast.]

Ec'Hinoidka.

*A8terias remondi Gabb (C). tumid us Remond (C). *Astrodapsi.s whitneyi Remond (C). Astrodapsis n. sp. Merriam (C). Scutella (Clypeaster) gabbi Remond (C).

*Cardium (cf. ) quadrigenarium Conrad (L). Cyrena californica Gabb. Dosinia ponderosa Gray (L). Gari alata Gabb (0) . *Glycymeri8 (-f Axineu) sp.

PELECYPODA — Continued.

, Macoma nasuta Conrad (L).

I *Mac'tra Ciilifomica Conrad (?) (L).

Maetra falcata Gould (L). I sp. (C ?).

*Mulinia densata Gabb (C).

Mytilussp. (C?). I Ostrea bourgeosii Gabb (C). I Ostrea titan Conrad (C).

Pectin andersoni n. sp.

I Pecten pabloensis Conrad (C).

Pecten cransicardo Conrad. Pinna alamedensis Yates.

a Merriam. J. (.'.. 1898, p. 113.

feTumer, H. W., Jour. Geol., vol. 6, pp. 483 et seq., from which a part of this list is copied.

Tertiary And Quaternary Pectens Of California.

List of San Pablo formation {upper Miocene) fosnUs — Continued.

PELBC'YPODA — continued.

Pseudocardiuni gabbi K<!'moud. *Saxidomu8 gracilin Gould (L). 8olen sp.

Tapes staminea Conrad (L). Tapes staleyi Gabb (?). *Tre8U8 nuttalli Conrad (L). ♦Zirphwasp. (C ?)

*Acmaja sp. (C). Bittiuni aeperuni Gabb (L). Calliostoma n. sp. (?) Merriam (C?) ♦Chlorostoma (?) sp. (C ?). Crepidula adunca Sowerby (L). Crepidnla princeps Conrad ? (L).

I OA8TERoionA —

Fusus (?) sp. (C ?).

Litorina rmondi Gabb (C). I Litorina planaxis Phil. (L).

Lunatia lewisii Gould (L). I *Oinebra (aff.) cancelling Philippi (C). I Ocinebralurida Middendorf*(?) (L).

*01ivella pedroana (L).

(C?).

Purmra canaliculata Duclos (L). j Purpura saxicola Valenciennes (L). ; Ranella californica Hinds (L).

♦Tritonium (Priene ?) sp. (C ?).

♦Trochita filosa Gabb.

Trochita n. sp. Merriam (C).

Trophon jwrnderosum Gabb.

In addition to the above the following species have been found in the Santa Margarita formation (probable equivalent of the San Pablo) in the Salina.s Valley, Monterey County, and southward:

Lint ttf Siinttt Mnrynrita formation Stiu Phlo) foMila from tSfilioaj< and Mmthu'ard.

Ki'HINolDKA.

Astrodapsis tuinidus Kniontl. (idarih and fragments of tests.

Pelec'Ypoda.

Area canalis Conrad.

Area (cf. ) micrfKionta Conrad.

Cardium (cf.) meekianum Gabb.

Cardium (cf. ) (juadrigenarium Conrad.

Chione n. sp. (large; coarse

Chione sj>. (medium sized).

Glycymeris (cf. ) patulus Conrad.

Lima sp.

Mactra (cf.) californica

Mactra (cf.) falcata Gould.

Mytilus sp. (very large).

Ostrea attwoodi Gabb.

Ostrea bourgeoisie R<?mond.

Ostrea titan Conrad.

Pecten crassicardo Conrad.

Pecten discus Conrad.

Pecten eldridgei n. sp.

Peciten estrellanus

Pecten estrellanus var. terminus n. var.

PELEC Y io I A — contin ue< 1 .

Pecten hastiitus Sby. var. hericius (tould.

Pecten oweni n. sp.

Phacoides acutiliueatus Conrad.

Pseudocardium (cf. ) gabbi Remond.

Saxidomus (cf.) gibbosus Gabb.

8olen sicarius Gould.

Tresus sj).

Venus pertenuis (rabb.

Astyris sp.

Chorus belcheri Hinds.

Fusus (aff.) robustus Trask.

Nassa sp.

Natica or Neverita sp.

Ocinebra (aff.) cancelling Philippi.

Olivella (cf. ) Onrad.

Pisania n. sp. (aff.) fortis Car|)enter.

Trochita filosa Gabb.

Turritella sp.

Crustacea.

Balanus estrellanus Conrail. Tamiosoma gregaria Conrad.

Tertiary Formations. 25

Pliocene.

Two more or less distinct faunal zone are recognizable in the Pliocene; the lower characterized by many forms identical to or closely related to those of the Miocene; while the upper appears to lack these older species and contains but comparatively few forms which are not found living at the present time. The fauna of the Purisima formation is characteristic of the lower horizon, while that of the Merced represents the upper.

Purisima Formation. Type Locality.

The type locality is in the vicinity of the mouth of Purisima Creek, San Mateo County, Cal.

Name And Descriition.

This formation was named and described H. L. Haehl and Ralph Arnold in Proceedings of the American Philosophical Society, vol. 43, No. 175, 1904, pp.

Definition.

The Purisima formation consists of a series of conglomerates, fine sandstones, and sandy shales, with a total thickness of about 800 feet, and is typically developed in the vicinity of the lower portion of Purisima Creek, San Mateo County. The formation also covers a considerable territory in other parts of the Santa Cruz quadrangle, especially that portion of the area adjacent to the coast and north of Pescadero Creek. Beds of age probably equivalent to at least a part of the Purisima are known from the Cholame Valley, Monterey County, and elsewhere south of the type locality. At least a poition of the beds on Eel River, Humboldt County, are doubtless the equivalent of the Purisima. As pointed out by Ashley," the Purisima formation (his 'Transition beds") and its probable equivalents appear in their lower portions to be more or less transitional toward the Miocene.

Much uncertainty exists in the mind of the writer as to the exact relation existing between the Purisima and San Pablo formations. After a careful examination of a large amount of material from the type localities of the two formations and also from supposed equivalent formations in the Salinas Valley and adjacent regions, supplemented by field studies at most of the localities from which the material was obtained, it appears evident that the two formations are quite intimately related. Just exactly what the nature of this relation is, however, has not yet been determined. It is a complex problem, and is one which will require much careful field and laboratory study for its solution. The Purisima fauna, taken as a whole, appears to be younger than the aggregate San Pablo fauna, and for the sake of convenience will be tentatively considered as the later of the two.

a Ashley, G. H., Proc. California Acad. Sci., ser. 2, vol. 5, 1895, p. 330.

26 Tebtiaby And Quatebnary Pecten8 Of California.

The greater part of the San Pablo should, without question, \ye placed in the Miocene, while the major portion of the Purisima is undoubtedly Pliocene. In accordance with these facts each formation has been arbitrarily placed in that epoch with which it appears to be the more closely allied.

Localities.

Orescent City, Del Norte County.

Eel River, County.

Tomales Bay, Marin County.

Halfmoon Bay to Pescadero Creek, vicinity of La Honda, Alpine district, and ridge west of Portola

Valley, San Mateo County. Near mouth of Stevens Creek, Santa Clara County. West branch of Soquel Creek and Scott Valley, Santa Cruz County. Cholame Valley, Lewis Creek, and Priest Valley, Monterey County. Vicinity of Coalinga, Kreyenhagens, and the Kettleman Hills, Fresno County. Cosmalia, Santa Barbara County. Temescal Canyon in Santa Monica Mountains, Third street and Broadway tunnels in Los Angeles, and

San Fernando tunnel, Los Angeles County. Olinda, Orange County. Cerros Island, off the coast of Lower California, Mexico.

The fonnations exposed at the following localities probably represent the upper part of the Purisima and the lower part of the Merced, and correspond to Dall's San Diego formation:

Santa Barbara and Rincon asphalt mine, Santa Barbara County; Piru Creek and Eureka Canyon, Ventura County; Santa Monica Canyon and San Pedro, Los Angeles County; San Juan Capistrano, Orange County; San Diego and Pacific Beach, San Diego County.

Fauna.

The fauna of the Purisima in central California contains a few species which extend into the Vaqueros (lower Miocene), manj' more which are common to it and to the San Pablo (upper Miocene), and a large number which are found in the Merced above it or are living at the present time. A number of the species common to the San Pablo and the Purisima are not found in the Merced or later, while a large number of the species found in both the Merced and the Purisima do not extend into the San Pablo, so far as known. Quite a number of the forms found in the Purisima are peculiar to this formation. Of the total Purisima fauna, about 30 per cent are believed to be extinct.

The fauna of the Wildcat" series of Humboldt Count}', as determined by Merriam and given by Lawson," indicates the probable contemporaneit}' of at least a part of this series with the Purisima. The lower part of the San Diego formation probably represents the middle and upper portions of the Purisima.

Pect/i /(f una.— The PecUm fauna of the Purisima and supposed equivalent formations is as follows: P. alley! P, anhxiryl hartschi P. bell P. hellUainellatus P, cauriniM P, cerroHeuHVi P, coalingaenifh P. coopeid P, dilhrl P, estrellanm var. catalpa {HimiUe) (figanteuH hastaius and its varieties herichin fu'ndsii, nmmrchics strateguH P, hanlcyi P, heinpliilli,, P. islandlcm P, jordan P. latiau-

aLawson, A. C, Bull. Dept. Geol., Univ. Cal., vol. 1, 1894, No. 8, pp. 260-261.

Pliocene Formations.

rites P. Iaw807i{ P. hcontei P, meiriami,, P, nutteri P, opuntia P. owe?u\ P. pwnneleei, P. pedroamis P. purisimxiensis P. rivers P. steamsii P. tumeric P. veatchii P. wahburnei P, watts and P. watts var. moran.

The following species have been found in the Piirisima formation at different localities in the Santa Cruz quadrangle:

List of PuriMma formation (lower Pliocene) fossils,

[Those species marked with an asterisk (♦) are supposed to be characteristic; those followed by (M) are also found in the Miocene: those by (N) in the Merced, and those by (0 arc still living.]

Bchixoidea.

Astrodapeis n. sp. Merriam. Scutella interlineata Stimpson.

Brachiopoda.

Glottidia albida Hind?.

Pelecypoda.

Area canalis Conrad (M). Area trilineata Conrad (M). Callista angustifrons Conrad (M) (/?). Cardium meekianuni Gabb (M ?).

Cardium meekianum Gabb n. var. A. Chione gnidia Broderip and Sowerby (I). Chione sp.

Clidiophora punetata Conrad (/).

Corbula sp.

Cry ptomy a calif orniea Conrad (/).

Cryptomya n. sp. A. (aff. eal if orniea Conrad). Dosinia ponderosa Gray (/).

Dosinia sp.

*Lwvieardinm n. sp. (aff. substriatiim Conrad).

Leda (ef.) fossa Baird (/?).

Ledaaphria Dall (/).

Maconia ealcarea Gnielin (/).

Maeoina inquinata Deshayes (/).

Macoma nasuta Conrad (/).

Maetra ealifoniica Conrad (/).

Maetra hemphilli Dall (/).

Modiolus rectus Conrad (/).

Moerella salinonea Carpenter (/).

Mytilus mathewsonii Gabb (M).

Nucula castrensis Hinds (/).

Panomya ampla Dall (/).

Panopea generosa Gould (/).

Pecten hastatus Sowerby (smooth var.).

Pecten healeyi n. sp. Pecten nutteri n. sp. Pecten oweni n. sp.

Pecten purisimaensis n. sp. Phacoides acutilineatus Conrad (M). Phacoides nuttalli Conrad (/). Saxidomus gibbosus Gabb (M).

PELECYPODA — coutinued.

Siliqua lucida Conrad (/). Siliqua patula Dixon (Z). Spisula catilliformis Conrad (I). Spisula falcata Gould (Z). Solen sicarius Gould. Tapes staleyi Gabb (N) (M?). Tapes tenerrima Carpenter (/). Tellina (cf. ) congesta Conrad (M). *Tellina n. sp., A. Tresus nuttalli Conrad (M). Venus pertenuis Gabb (M). Yoldia cooperi Gabb (I). Yoldia scissurata Dall (/). Zirphaea gabbi Tryon

Gasteropoda.

Admete gracilior Carpenter (N).

Astyris californian Gaskoin (I),

Astyris gausapata Gould

Astyris richthofeni Gabb (N).

Bittium asperum Gabb (I).

Boreotrophon pacificus Dall (I).

*Buccinum n. sp. A.

*Calliostoma n. sp. A.

Chrysodomus liratus Marty n (l).

Chrysodomus tabulatus Baird (/).

*Chry8odomu8 n. sp. A.

Crepidula princeps Conrad (M) (N).

Crepidula navicelloides Nuttall (/).

Crepidula (cf. ) onyx Sowerby (I).

Crepidula rugosa Nuttall.

*Dolichotoma n. sp. (aff. carpenteriana Gabb).

Drillia incisa Carpenter (/).

*Fusus n. sp. (aff. rugosus Trask).

*Galerus inornatus Gabb.

Leptothyra paucicostata Dall (I),

Lunatia lewisii (iould (/).

Nassa californian Conrad (N).

Nassa mendica Gould (I).

Nassa perpinguis Hinds (/).

Natica clausa Broderip and Sowerby (I),

*Neptunea humerosa Gabb.

Tertiary And Quaternary Pecten8 Of California.

List of Purisima formation {lower Pliocene) fossils — Continued.

GASTEROPODA — Continued.

Neverita recluziana Petit (/). Oiivella intorta Carpenter (/). Pleurotoma perversa Gabb (I). Pleurotoma sp.

Priene oregonensis Redfield (l). Purpura crispata Chemnitz (/). Rostellaria indurata Conrad (M). Serpulorbis squamigerus Carpenter (I).

a ASTEROPOD A — Continued.

Sigaretus debiiis Gould (/). Solariella peramabilis Carpenter (/). Tomatina cuicitella Gould (/). Triton ium sp. ♦Voluta n. sp. (?) A.

Crustacea.

Balanus estrellanus Conrad (M).

The San Diego formation in a general way is the representative of the Purisima in southern California, although the former, at least the fossiliferous horizon, may not extend as far back in the time scale as the base of the latter. The fauna of the San Diego formation as developed in the type section at Pacific Beach, north of San Diego, San Diego County, is as follows:

IJM of San Diego formation fossils. [Thoee marked with an asterisk are supposed to be extinct.]

Echinoidea.

Echinarachnius excentricus Eschscholtz. Strongylocentrotus purpuratus Stimpson.

Laqueus jeffreyei Dall.

Pelecypoda.

Leda taphria Dall.

Macoma nasuta Conrad.

Mactra (Spisula) catilliformis Conrad.

Metis alta Conrad.

Modiolus rectus Conrad.

Ostrea veatchii Gabb.

Pecten ash ley i n. sp.

Pecten bellilamellatus n. sp.

Pecten cerrosensis (iabb.

Pecten cooperi n. sp.

Pecten hastatus Sowerby.

Pecten hastatus var. hericius (rould.

PELECYPODA — contiuued.

Pecten hastatus var. navarchus Dall. Pecten healeyi n. sp. Pecten Dall. Pecten opuntia Dall. Pecten stearnsii Dall. Phacoides acutilineatus Conrad. Phacoides nuttalli Conrad (=Lucina id.). Pododesnius macroschisma Deshayes, Tapes staminea Conrad.

Gasteropoda.

Crepidula Conrad.

Dentalium Sharp and Pilsbry.

Neverita recluziana Petit.

Oimlia anoinala Stearns.

( )palia varicostata Stearns.

crisimta Chemnitz.

Scala stearnsii Dall.

Scala tincta Carpenter.

Turritella Carpenter.

Mercki) Forma Tion. Type

The type locality is the sea cliff south of Lake Merced, San Mateo County, Cal.

Name And

This formation was named and described by A. C Lawson, in Bulletin of the Department of Geology, University of California, vol. 1, No. 4, 1893, pp. 142 et

Pliocene Formations. 29

Definition.

The type section of the Merced formatiou consists of a series of rather soft, gray sandstones and sandy shales, interbedded with liard pebbly conglomerates, hard well-cemented shell layers, and occasional lignitic seams. The total thickness of the formation is approximately 5,000 feet. In age the Merced probably represents the upper Pliocene and lower Pleistocene, although there is no apparent unconformity in the type section, which is certainly Pliocene at the base and Pleistocene at the top.

Ixxtalities.

f!Ulun beds, Shoal water Bay, Oreg. (Dall, 1898, p. 336).

Upper portion of the "Wildcat formation," Kel River, Humboldt County (?).

Sea cliffs south of Lake Merced and foothills between them and Twelvemile Creek; north of

Pillar Point; uppennost leds in sea cliff at mouth of Nuevo Creek, San Mateo

County. Felt Lake, near Stanford University, Santa Clara County. Uppermost beds at Capitola, Santa Cruz County. Beds at Bath House Beacth and at least a portion of Packards Hill beds, Santa Barbara, Santa

Barbara County. Old irrigating ditch north of Ventura, Ventura County. Pliocene and lower portion of San Pedro formation, Deadmau Island and San Pedro; Santa

Monica Canyon, Los Angeles County. San Juan Capistrano, Orange County. Upper portion of San Diego formation. Pacific Beach, and San Diego, San Diego County.

Fauna.

The fauna of the lower beds in the Merced formation indicates clearly their Pliocene age, while at the top the fossils show the Pleistocene origin of this part of the formation. In using "Merced'' in its broader sense as a horizon name in the California column it is deemed advisable to confine it, in a general way, to that period of the standard geologic scale (viz, the Pliocene) to which the great bulk of the sediments of the formation belong. In correlating, however, the equivalence of the lower portion of the next higher formation (the San Pedro) to the upper portion of the Merced should le borne in mind.

Pecten faima, — No Pectens have so far been recorded from the type section of the Merced, although beds of probable equivalent age to the Pliocene portion of it have yielded the following species: P, ashley! P, hell P, helllhimellatm P, caurhniH P, cerrosehsis coop/'f\ P, {) gtfjanteus P, hmtatm and its varieties hericlus hhuhii nararchu and P, healey! P. heinphilli P. islandtcvs P, Jordan P, latiatfrltus P, opuntliu P- purinelee} P, I'lversi and P, stednisli.

The following fauna has been found at or in the immediate vicinity of the type loaility of the Merced formation, and may be taken as characteristic of the horizon represented by the whole formation:

Tertiary And Quaternary Pecten8 Of California.

List of Merced formation {upper Pliocene) fossils

[Those unmarked have been reported from the tjrpe locality; thoee followed by (T) have been found only at Twelvemile Creek or Twelvemile House: those with (F) between Mussel Rock and Twelvemile House, and those with (S) at Felt Lake, near Stanford University. Those species marked with an asterisk are supposed to be extinct.]

Echinoidka.

Echinarachnius excentricus Eschscholtz.

Scutella interlineata Stimpson.

Pelecypoda.

*Arca trilineata Conrad. Cardium corbis Martyn.

Cardium meekianuin Gabb. Cardium quadrigenarium Conrad (F). Chione succincta Valenciennes. Cryptomya californica Conrad. Macoma calcarea Gmelin.

Macoma inquinata Deshayes (T). Macoma nasuta Conrad. Macoma (like sabulosa . ). Mactra californica Conrad. Modiolus rectus Conrad (T). Mytilus californianus Conrad. Mytilus edulifl Linn. Ostrea sp. ?

Pecten latiauritus Conrad (S). Pododesmus macroschisma Deshayee. Psephis lordi Baird.

Saxidomus gibboeus Gabb. Saxidomus gracilis Gould. Siliqua patula Dixon. Solen sicarius Gould. Spisula falcata Gould.

Tapes staleyi Gabb. Tapes staminea C/onrad.

PELECYPODA — coutiuued.

Tresus nuttalli Conrad. Venericardla ventricosa Gould.

Gasteropoda.

Astyris gausapata Gould. *Astyri8 richthofeni Gabb. Bittium asperum Gabb. Bittium filosum Gould. Chrysodomus liratus Martyn. Chrysodomus tabulatus Baird. Crepidula princeps Conrad. Crepidula navicelloidea Nuttall. Drillia incisa Carpenter. Drillia inermis Hinds*. Litorina planaxis Philippi (S). Limatia lewisii Gould. Monoceros engonatum Conrad. Margarita pupilla Gould (S). assa fossata Gould. Nassa mendica Gould. Natica clausa Broderip and Sowerby. Olivella biplicata Sowerby. ' Olivella intorta Carpenter. Pleurotoma sp. indet. (F). Purpura canal iculata Duel. Purpura saxicola Valenciennes. *Trochita filosa Gabb. Turritella sp.

In southern California the Merced is represented by a somewhat different fauna from that found at the type locality. The Pliocene of Deadnian Island, Los Angeles County, though representing a horizon probably a little lower than the bulk of the Merced, has a fauna which may be taken as approximately representing the Merced horizon in the southern part of the State. This Deadman Island fauna is as follows:

List of Pliocene fossils from Dendman Island. [ThoNc marked with an asterisk (♦) are to be extinct.]

Anthozoa.

Caryophyllia californica Vaughan

Brachiopoda.

Laqueus jeffreysi Dall. *Terebratalia smithi Arnold.

oLawfion, A. C, ]

Pelecypoda.

Chama pellucida Sowerby. Corbula luteola Carpenter. Cumingia californica Conrad. Kellia laperousii Deshayes. Leda taphria Dall. 1, pp. 144-145; 1895, p. 460; also Ashley, G. H., 1895, pp. 332-333.

Plei8To0Kne Fobmation8.

List of Pliocene fomU from Deadman Island — Continued. PELBCYPODA — Continued. gasteropoda — continued.

Lyonsia californica Conrad.

Macoma calcarea Guielin.

Macoma inquinata Deshayes.

Marcia sulxliaphana Carpenter (dementia id.)

Mytilimeria nuttalli Conrad.

Nucula castrensis Hinds. .

Panornya Dall.

Panopea generona Gould.

Pecten caurinus Gould.

Pecten haptatus Sowerby.

Pecten hattatu8 var. hericius Gould.

Pecten hastatus var. hindsii Carpenter.

Pecten jordan Arnold.

Pecten Htearnsii Dall. Phactoides acutilineatus Conrad. Phacoides californicus Conrad. Pholadidea Conrad. Protocardia centifilosa Solen BicariuK Gould. *Thracia trapezoides Conrad. Thyasira gouldii Philippi. Thyasira bisecta Conrad. Venericardia lrbarennis Stearns. Venericardia ventricosa (JouIjI. Venus (Chione) simillima Sowerby.

Gasteropoda.

Acmtva insessa Hinds. Amphissa corrugata Reeve. Bela fidicula Gould. Bittium asperurn Gabb. Calliostoma canaliculatuni Martyn. CallioHtoma tricolor Gabb. Cerithidea califoniica Haldemann. Chlorostoiua brunneum Philippi. Chlorostoma monterey Kiener. Chrysodonius sp. indet. Chrysodonius rectirostris Carpenter. Chrysodomus tabulatus Baird. Clathurella conradiana (iabb. Coluinbella gausapata (Jould. Colunibella gausapata var. carinata Hinds.

Conus californicus Hinds. Cryptochiton stelleri Middendorf.

Drillia merriami Arnold. Drillia torosa Carpenter. Fusus barbarensis Trask. Hipponyx antiquatus Linn. Litorina planaxis (Nuttall) Philippi. Mangilia sculpturata Dall.

Nassa californian Connwl.

Nassa fossata Gould.

Nassa mendica Gould.

Niissa mendica var. cooperi Forbes.

Nassa Hinds.

Natica clausa Broderip and Sowerby.

Neverita reduziana Petit.

Ocinebra inter fossa Carpenter.

Olivella Sowerby.

Olivella intorta Carpenter.

Olivella pedroana Conrad.

Pleurotoma bartschi Arnold.

Pleurotoma dalli Arnold. Pleurotoma Gabb.

Pleurotoma renaudi Arnold.

Pleurotoma smithi Arnold. Priene oregonensis Redfield. Puncturella cucuUata Gould. Puncturella galeata Gould. Scala indianorum Carpenter. Solariella cidaris A. Adams. Solariella peramabilis *Taranis strongi Arnold. Terebra simplex Carpenter. Thalotia caffea (iabb. Tornatina eximia Baird. Troplion gracilis Perry. Trophon pacificus Dall. Trophon stuart Smith.

Trophon orpheus var. pnvcursor Arnold. tenuisculpta Carpenter. Turritella cooperi Carpenter.

Turritella jewetti Carpenter.

Pleistocene.

The marine Pliocene and Pleistocene deposits of California are intimately associated, and at many places grade into each other with no perceptible physical break between them. At others, however, an unconformity exists between the two, and in some localities the Pleistocene itself may be separated into two divisions, with a more or less distinct line of demarcation between them. Such a condition as that last 'mentioned is found in the vicinity of San Pedro, Los Angeles Count}, where

32 Tebtiary And Quaternary Pecten8 Of California.

probably the best development of the fossiliferous marine Pleistocene on the coast is exposed. This locality is taken, therefore, as the type for the Pleistocene of California.

Sax Pedro Formation.

Type Locality.

The type locality is vicinit} of San Pedro, Angeles County, Cal.

Name And Description.

This formation was named and described by W. H. Dall, Table of North American Tertiary horizons: Eighteenth Ann. Kept. U. S. Geol. Survey, pt. 2, 1898, p. 335.

Definition.

As redefined by the writer, this formation includes '' all of the strata of Deadman Island and San Pedro lying stratigraphically above the brown Pliocene sandstone and below the raised beach formation of Deadman Island." In the type locality the San Pedro consists of a series of conglomerates and sands, both more or less incoherent and extremely fossiliferous, with a total thickness of approximately 100 feet. Near Ventura, beds of probable similar age attain a thickness of about 1,000 feet.

The formation may be divided into two distinct horizons — a lower and an upper — semrated at all points in the vicinity of the type locality an unconformity. The lower part of the formation represents at least the base of the Pleistocene, and may possibly extend into the Pliocene. It is probably contemporaneous with the upper portion of the Merced, and contains a fauna which appears to be transitional between that of the Pliocene on which it rests and that of the characteristic Pleistoc*ene above.

The upper beds of the San Pedro formation are certainly Pleistocene, and as their fauna is more or less characteristic it will be cited as typical of the major portion of the Pleistocene.

Localities.

Deposits contemporaneous in a general way with the San Pedro formation, particularly the upper division, occur at numerous places along the coast from Alaska to Lower California. Only those localities known to be fossiliferous will be cited, however. They are as follows:

Point Holinet?, Coinox, Vancouver iHland, British Columbia Port Blakeley, near SeattK*, WaHh., and other locaHties in the Puget Sound country. Fossil Point,' Coos Bay, Orep. (Dall, 1898, p. 836).

Ilwaco, near the mouth of the Columbia River, and Newport, Oreg. (Diller, 18%, p. 479 et seq.) Fort Ross*, Humboldt County.

PuriHima and Punta Afio Nuevo, San Mateo County.

South shore of San Pablo Bay (unconformably above the San Pablo formation), Contra Costa County. Santa Cruz, Santa Cruz County.

Vicinity of Ventura and Sunmierland, Ventura County.

San Beach, Bells Station, and Los Cerritos Hill, Angeles County. Newjwrt, Orange County. Two miles south of Delmar, Pa<'ific Beach, Spanish Bight, and San Diego, San Diego

a Arnold, Delo and Ralph, The marine Pliocene and Pleisto<'ene Htratigraphy of the coast of southern California: Jour. Geol., vol. 10, 1902, p. 124.

Pleistocene Formations.

Fauna.

The fauna of the upper portion of the San Pedro formation consists of species which are nearly all found living at the present time. One noticeable thing regarding this fauna is the fact that wherever found it generally contains species which, though living, are found now only south of the locality yielding the fauna; thus indicating somewhat more tropical conditions during the Pleistocene than are prevalent at the present time on the California coast.

Pecten fauna, — The Pecten fauna of the upper, or chamcteristically Pleistocene, portion of the San Pedro and equivalent formations is as follows: Pecten aldskensis P. caurimii*, P, and variety sequwxdcatiis P. dlegenms P. {Hinnites) glganteuM. P. hastatics and varieties heridmj hind-mli nava7Thm, and strategns P. islandlcu P, Idfiaurituit and varieties cerritensls delo%i fucicohn* and monotimsria P, and P, rogdesl.

The following fauna has been found in the upper of the San Pedro formation in the vicinity of the type locality, and may be taken as characteristic of the Pleistocene for the coast of California:

List of San Pedro formation {Pleistocene) fossil. [Thoee marked with an asterisk are known so fart San Pedrt> only from the |)ortion of the San Pedro formation.] ANTHozoA. PELECYPODA — (!ontinued.

Caryophyllia arnoldi Vaughan. Caryophyllia pedroerLsis Vaughan. Paracyathus peclroensis Vaughan.

Echinoidea.

Echinarachniua excentricus Eschacholtz. Strongylocentrotus franciscanus Agassi z. StrongylocentrotUH purpuratus Stimpson.

Pelecypoda.

Aligena cenitensis Arnold.

Amiantih! cllosa Conrad.

Angulus button Dall.

Anomia lampe (J ray.

Area labiata Sowerby.

Astarte (Crassinella) branneri Arnold.

*Bomia retifera Dall.

Callista newconibiana Gabl).

*Calli8tata subdiaphana Carpenter.

Cardita (Carditamera) suVKjuadrata Carpenter.

(Tzaria id.) Cardiuin corbis Martyn. Cardiuni elatuni Sowerby. Cardium procerum Sowerby. Cardiuin <iuadrigenarium Conrad. Chama exogyra Chaina pellucida Sowerby. Clidiophora punctata Conrad. Cooperella subdiaphana Carpenter.

17260— No. 47—06 3

Corbula luteola Carpenter. Cryptomya califomica Conrad. Cuniingia california Conrad. Diplodonta orbella (rould. Diplodonta serricata Reeve. Donax califomica Conrad. Donax hevigata Deshayes. Glycymeris barbarensis Conrad. GlycymeriH septentrionalis Middendorf. *Kellia suborbicularis Montague. *Kellia laperousii Deshayen. *Kennerlia biciirinata *Kennerlia filosa Carpenter. Lievicardium Conrad. fossa Baird. *Leda hauiata Car[)enter. minuta var. Arnold. Leda taphria Dall. *Linia ilehiscens Conrad. Lithophaga plumula Ilanley. lA'onsia califomica Conrad. *Macoma calcarea Gnielin. Macoma indentata Carpenter. Maconia inquinata Deshayeh. Macoma nanuta Maconia nasuta var. kelseyi Dall. Macoma secta Conrad. Macoma yoldiformis Carpenter. Mactra califomica C/onrad.

Tertiary And Quaternary Pecten8 Of California.

LiM of San Pedro formation (PUiMocene) fossiU — Contiinu'<l. rELKCYPODA — ooiitinued. — (continued.

Mactra exoleta Gray.

Mactra hemphilli Dall.

Metis alta Conrad.

Moiliolus fomicatus Carpenter.

Modiolus rectus Conrad.

*Moerella salmonea Carpenter.

*Mytilimeria nuttalli Conrad.

Mytilus eduiis Linn\

*Neaira pectinata Carpenter.

*Nucula (Acila) castrensis Hinds.

Nucula suprastriata Carpenter.

Ostrea lurida Carpenter.

*Panomya ampla Dall.

Panopea generosa Gould.

Pecten caurinus Gould.

Pecten circularis Sowerby.

Pecten circularis var. aniuisulcatus Carpenter.

Pecten hastatus Sowerby.

♦Pecten hastatus var. hericius

*Pecten hastatus var. strategun Dall.

*Pecten joniani Arnold.

Pecten latiauritua Conrad.

Pecten latiauritus var. cerritensin n. var.

*Pecten latiauritus var. delosi n. sp.

Pecten latiauritus var. monotimeris Conrad.

Pecten subncxlosus Sowerby.

Pecten vogdesi n. sp.

Periploma argentaria Conrad.

Petricola crditoides Conrad.

Petricola (Petricolaria) cognata C. B. Adamn.

Petricola denticulata Sowerby.

Phacoides (-f-Lucina) acutilineatus Conrad.

Phacoides (Lucina) calif omicus Conrad.

Phacoides ( -f Lucina) tenuisculptus

Pholadidea penita Conrad.

Platyodon cancellatus Conrad.

Pododesmus (Monia) macroschisma Deshayes.

*Protocanlia centifilosa Carpenter.

Psammobia edentula (xabb.

♦Psephis salmonea Carpenter.

Rupellaria lamellifera Conrad.

Sanguinolaria nuttalli Conrad.

Saxidomus gracilis (lOiild.

Semele decisa Conrad.

Semele pulehra Sowerby.

Semele pulehra var. monterey Arnold.

*Septifer bifurcatus Conrad.

Siliqua lucida Conrad.

Siliqua patula Dixon var. nuttiiUi Conrad.

Solen sicArius Gould.

Spisula catilliformis Conrad.

Spisula falcata Gould.

Tagelus califomianus Conrad. Tapes ladneata Carpenter. Tapes tenerrima Carpenter. Tellina bodegensis Hinds. Tellina idee Dall. Tellina rubescens Hanley. *Thracia trapezoides Conrad. ♦Thyasira gouldii Philippi. Tivela crassatelloides Conrad. Tresus nuttalli Conrad. Venericardia barbarensis Stearns.

Venericardia ventricosa Gould. Venus tantilla Gould (Psephis id.). Venus (Chione) fluctifraga Sowrby.

Venus (Chione) gnidia Broderip and Sowerby. Venus (Chione) neglecta Sowerby. Venus (Chione) simillima Sowerby. Venus (Chione) succincta Valencibnnes.

Verticordia novemcostata Adams and Reeve. Yoldia cooperi Gabb.

Yoldia scisaurata Dall. Zirphfiea gabbi Try on.

(Gasteropoda.

Acma?a depict Gould.

Acniiea insessa Hinds.

Acniapa instabilis Gould.

Acmwa mitra Eschscholtz.

Acmsea paleacea Gould.

Acmsea delta Kschscholtz.

Acmaea spectrum (Nuttall) Reeve.

Actaeon (Rictaxis) punctoccelata

Actseon traskii Stearns.

Admete gracilior Carpenter.

Amalthea antiquata Linn6. (Hipponyx id. ) Amalthea cranioides

Amalthea tuniens Carpenter. Amphissa Reeve.

Amphissa ventricosa Arnold. Amphissa versicolor Dall. Bela fidicula Gould.

Bela sancta-monica* Arnold. Bittiuni asperum Gabb.

Bittium califomicum Dall and Bartsch Bittium filosura Gould.

Bittium (juadrifilatum Carpenter. Bittium rugatum Carpenter. Bittium williamsoni Arnold. Bulla punctulata A. Adams. Bulla quoyi Gray.

Cadulus fusiformis Sharp and Pilsbry. Cacum califomicum Dall.

Pleistocene Formations.

LiH of San Pedro formation Pielatoonw) fossils — Continued.

—

Oecum civbricinctuni Carpenter.

Cwcum magnum Stearns. Callioetoma annulatum Martyn.

( -allioetoma ranaliculatum Martyn.

('alli<)*toma (tontatum Martyn.

Calliostoma jremmulatum

CallioHtoma tricolor Gabb.

Cancellaria cooperi (labb.

( 'ancellaria trrawfordiana Dall.

Cancellaria tritonidea (iabb.

Cerithidea californica Haldemann.

Chloroetoma aureotinctum Forben.

Chlorostoma brunneum Phillppi.

ChloroHtonia funebrale A. Adams.

ChloroHtoma funebrale var. RibafHirtum

Chloro><toma gallina Forbes.

ChloroHtoma monterey Kiener.

Chlorostoma pulligo Martyn (Ihorcus id.).

ChloroHtoma (Oniphalius) virilulum var. ligula-

tum Menke. Chorus Hinds. ''hrysoilomuH rectirostris Carpenter.

ChrysoiloniUH tabuatus Bainl. (/lathurella conradiana Gabb. *Columbella (Astyris) californian Gaskoin. Columbella (yEsopus) chrysalloidea Carpenter. Columbella (Astyns) gausapata Gould. Columbella (Astyris) gausapata var. carinata

Hinds. Columbella (Anachis) minima Arnold.

Columbella (.i!>>opu8) oldrtiydi Arnold. solidula var. precursor Arnold. Columbella (Astyrihi) tuberosa Carpenter. Conus californicus HindH. Coralliophila nux Reeve.

Crepidula aculeata Gmelin. Crepidula adunca Sowerby. Crepidula dorsata Bnerip. Crepidula princeps (Conrad. Crepidula onyx Sowerby. rugosa Nuttall. Crucibulum npiiioHum Sowerby. *Cryptochiton Htelleri Middendorf. Cylichna alba Brown.

Cyjint'a (Jray.

Cythara branneri Arnold. Dentalium indianorum Carpenter. Dentalium neohexagonum Sharp and Pilsbry. Dentalium pseudohexagonum Dall. Dentalium seniipolitum Broderip and Sowerby.

Diastoma, np. indet. Drillia can<'ellata Carpenter.

(iAsTEROPODA — contlnued.

Drillia hemphilli Stearns.

Drillia inermis Hinds.

Drillia inermis var. penicillata Carpenter.

Drillia johnsoni Arnold.

Drillia merriami Arnold.

Drillia montereyensis Stearnw. Drillia pudica Hinds.

Drillia torosa Erato columbella Menke.

Eulima falcata Carpenter. Eulima hastata Sowerby. Eulima micans C'carpenter. Kupleura muricifonnis Broderip. Eupleura muricifonnis var. tmrta .\arnold. Fissuridea aapera Eschscholtz. Fi.ssuridea infe<|ualis Sowerby. Fissuridea murina (Carpenter) Dall. FisHurella volcano Reeve.

FuU8 Imrbarensis Trask.

Fusus luteopicius Dall.

Fusus robustus Trask.

'Fusus nig03us Trask (=F. amoldi Cossmann).

(ladinia reticulata Sowerby.

Galerus mammillaris Broderip.

Haliotis fulgens Philippi.

Haminea virescens Sowerby.

Helix (Epiphragmophora) sj). indet.

Isapis feneatrata Carpenter.

Ischnochiton regularis Carpenter.

Ivara turricula (Carpenter) Dall Bartch. Lacuna compacta Carpenter.

Lacuna porrecta Carpenter. I.A<'una solidula (Loven) Carpenter.

Lamellaria steamnii Dall. Leptothyra bacula Carpenter. Iptothyra carpenteri Pilsbry.

Ieptothyra {mucicowtata Dall. Litorina planaxis (Nuttall) Philippi. Litorina scutulata Gould. Lucapina crenulata Sowerby. Lucapinella callomarginata Carpenter. Macron kellettii A. Adams. Mrnron lividus A. Adams. Mangilia angulata Carpenter. Mangilia hooveri Arnold.

Mangilia interfossa var. Arnold. Mangilia interlirata Stearns.

Mangilia oldroydi Arnold.

Mangilia paiuei Arnold.

Mangilia sculpturata Dall. Mangilia striosa C-. B. Adams. Margarita optabilis var. knechti Arnold.

Tebtiary And Quaternary Pecten8 Of California.

Limit of San Pedro formation (Pleistoceiu) fossiU — ContiiiiUMl. — continued. pelbcypoda — continued.

Mactra exoieta Gray.

Mactra hemphilli Dall.

Metis alta Conrad.

Modiolus fomicatus Carpenter.

Modiolus rectus Conrad.

*Moerella salmonea Carpenter.

*Mytilimeria nuttalli Conrad.

Mytilus edulis Linn('\

*Neajra pectinata Carpenter.

*Nucula (Acila) castrensis Hinds.

Nucula suprastriata Carpenter.

Ostrea lurida Carpenter.

*Panomya ampla Dall.

Panopea generosa Gould.

Pecten caurinus Gould.

Pecten circularis Sowerby.

Pecten circularis var. Carpenter.

Pecten hastatus Sowerby.

*Pecten hastatus var. hericius (rould.

*Pecten hastatus var. strategus Dall.

*Pecten jordan Arnold.

Pecten latiauritus Conrad.

Pecten latiauritus var. cerritensin n. var.

*Pecten latiauritus var. delosi n. sp.

Pecten latiauritus var. monotimeris Conrad.

Pecten subnodonus Sowerby.

Pecten vogdesi n. sp.

Periploma argentaria Conrad.

Petricola (arditoides Conrad.

Petricola (Petricolaria) cognata C. B. Adamn.

Petricola denticulata Sowerby.

Phacoides (-f-Lucina) acutilineatus C/onrad.

Phacoides (+Lucina) califomicus Conrad.

Phacoides ( j-Lucina) tenuisculptus Carjienter.

Pholadidea penita Conrad.

Platyoilon cancellatus Conrad.

Pododesmus (Monia) inacroschisnia Deshayes.

*Protocardia cutifilosa Carpenter.

Psammobia Gabb.

*Psephi8 salmonea Carpenter.

Rupellaria lamellifera Conrad.

Bangui nolaria nuttalli Conrad.

Saxidomus gracilis Gould.

Seniele decisa Conrad.

Semele pulchra Sowerby.

*Semele pulchra var. monterey Arnold.

*Septifer bifurcatus Conrad.

Siliqua lucida Conrad.

Siliqua ])atula Dixon var. nuttalli Conrad.

Solen sicArius Gould.

Spisula catillifonnis Conrad.

Spisula falcata Gould.

Tagelus califomianus Conrad. Tapes ladneata Carpenter. Tapes tenerrima Carpenter. Tel Una bodegensis Hinds. Tellina idje Dall. Tellina rubescens Hanley. *Thracia trapezoides Conrad. *Thya8ira gouldii Philippi. Tivela crassatelloides Conrad. Tresus nuttalli Conrad. Venericardia barbarensis Stearns. ventricosa Gould. Venus tantilla Gould (Psephis id.). Venus (Chione) fluctifraga Sowrby. Venus (Chione) gnidia Broderip and Sowerby. Venus (Chione) neglecta Sowerby. Venus (Chione) simillima Sowerby. Venus (Chione) succincta Valencibnnes. I Verticordia novemcostata Adams and Reeve. Yoldia cooperi Gabb.

Yoldia scissurata Dall. Zirphea gabbi Tryon.

Acmsea depict Gould.

Acnia'a insessa Hinds.

Acmnea instabilis Gould.

Acmiea mitra tchscholtz.

Acmsea ])aleacea Gould.

Acmsea delta Pschschoitz.

Acmsea spectrum (Nuttall) Reeve.

(Rictaxis) punctoccelata Carpenter.

Actseon traskii Steams.

Admete gracilior Carpenter.

Amalthea antiquata Linn6. ( Hipponyx id. ) Amalthea cranioides Carpenter.

Amalthea tumens Carpenter. Amphissa corrugata Reeve.

Amphissa ventricosa Arnold. Amphissa versicolor Dall. Bela fidicula Gould.

Bela 8anct?-monic8e Arnold. Bittiuni asperuni Gabb.

Bittium califomicum Dall and Bartsch Bittium filosum Gould.

Bittium quadrifilatum Carpenter. Bittium rugatum Carpenter. Bittium williamsoni Arnold. Bulla punctulata A. Adams. Bulla quoyi Gray.

Cadulus fufiiformis Sharp and Pilsbry. Cspcura califomicum Dall.

Pleistocene Fobmation8.

LiM of San Pedro formation [Plfistocene) fools — Continued. ( JARTKRopoDA — Continued. (jasteropoda — continued.

Ciecuin crebricinctuni Carpenter.

Ca'cum magnum 8learn8. Callioetoma annulatum Marty n. CallioHtoma canal iculaturn Marty n. CallioHtoma costatuni Martyn. CallioHtoma gemmulatuni tricolor Gabb. Cancellaria (iabb. Cancellaria crawfordiana Dall. Cancellaria tritonidea (iabb. Cerithidea californica Haldemann. ChloroHtoma aureotinetum Forben. ChloroHtoma brunneum Philippi. Chloroytonia funebrale A. Adams. ChloroHtoma funebrale var. Hubapertiim ChloroHtoma gallina Forbet*.

ChloroHtoma monterey Kiener. Chlorostoma pulligo Martyn (PhorcuH id. ). Chlorostoma (Ornphalius) viridulum var. ligula-

tum Menke. Chorus belcheri Hinds. .'hryHodomus rectirostris Carpenter. *Chry80flonni8 tabuatus Baird. Clathurella conradiana Gabb. (.Vstyris) californian Gaskoin. Columlella ( Enopus) chryaalloidea Carpenter. C'olumbella ( Astyns) gausapata Gould. Columbella (Astyris) gausapata var. carinata

Hinds. Columbella ( Anachis) minima Arnold.

Columbella (.Esopus) oldroydi Arnold. nolidula var. Arnold. Columbella (Astyris) tuberosa Carpenter. Conus californi(;u8 Hinds.

Coral liophila nux Reeve. *Crepidula aculeata (imelin. Crepidula adunca Sowerby. Crepidula dorsata Broderip. Crepidula princeps Conrad. Crepidula onyx Sowerby. Crepidula rugosa Xuttall. Crucibulum spinosum Sowerby. *Cryptochiton stelleri Middendorf. Cylichna alba Brown. Cypnt'a spadicea (tray.

Cy thara branneri Arnold. Dentalium indianorum Carpenter. Dentalium neohexagonum Sharp and Pilsbry. Dentalium pseudohexagonum Dall. Dentalium semipolitum Broderip and Sowerby.

Diastoma, sp. indet. Drillia cancel lata Carpenter.

Drillia hemphilli Steams.

Drillia inermis Hinds.

Drillia inermis var. penicillata ('carpenter.

Drillia johnsoni Arnold.

Drillia merriami Arnold.

Drillia montereyensis Stearns. Drillia pudica Hinds.

Drillia torosa Erato Menke.

Eulima falcata Carpenter. Eulima hastata Sowerby. Eulima micans Carpenter. Eupleura muriciformis Broderip. muriciformis var. curta Arnold. Fissuridea Eschscholtz. Fi.s8uridea inajualis Sowerby. Fiisuridea umriua (Carpenter) Dall. Fissurella volcano Reeve.

j Fusus barbarensis Trask.

Fusus luteopietus Dall. I Fusus robustus Trask.

Fusus rugosus Trask (=F. amoldi ( Jadinia reticulata Sowerby.

( lalerus mammillaris Broderip. Haliotis fulgens Philippi. Haminea virescens Sowerby. Helix (Epiphragmophora) sp. indet. Isapis fenestrata Carpenter. Isi'hnochiton regularis

I vara turricula (Carpenter) Dall and Bartsch. Lacuna compacta Carpenter.

Lacuna porrecta Carpenter. La<*una ( Loven ) Carpenter.

Lamellaria stearnsii Dall. Leptothyra bacula Carpenter. Leptothyra carpenteri Pilsbry.

leptothyra paucicostata Dall. Litorina planaxis (Nuttall) Philippi. Litorina scutulata Gould. Lucapina crenulata Sowerby. Lucapinella callomarginata Carpenter. Macron kellettii A. Adams. Macron lividus A. Adams. Mangilia angulata Carpenter. Mangilia hooveri Arnold.

Mangilia interfossa var. ][)edroana Arnold. Mangilia interlirata Stearns.

Mangilia oldroydi Arnold.

Mangilia painei Arnold.

Mangilia sculpturata Dall. Mangilia striosa C. B. Adams. Margarita optabilis var. knechti Arnold.

Tertiary And Quaternary Pe0Ten8 Of California.

IMt of Situ Pedro formation (Phiatocene) fomh — Continutl. GASTEROPODA— con (ahteropoda — continued.

Margarita optabilis var. nodosus Arnold. Margarita parcipicta var. pedroana Arnold. Maiiginella jewettii Carpenter. Megatebennus bimaculatus Dall.

Mitra maura Swainson.

Mitramorpha filosa Carpenter. intermedia Arnold. Monocerofl engonatuni Conrad. Monoceros lapilloides Conrad. Mopalia ciliata Sowerby.

Murex (Pteronotus) festivqa Hinds.

Murex (Pterohytia) foliatus Martyn.

Murex (Pterohytis) nuttalli Conrad.

Murex (Cbicoreus) leeanus Dall.

Murex (Cerostonia) monoceros Sowerby.

Murex trialatus Sowerby.

Nassa californian Conrad.

Nassa cerritensis Arnold.

Nas$a fo8sata Gould.

Nassa insculpta Carpenter.

Nassa mendica Gould.

Nassa mendica var. Forljes.

Nassa perpinguis Hindn.

Nassa tegula Reeve.

Nassa versicolor var. hooveri Arnold.

Natica clausa Broderip Sowerby. Natica ( Lunatia) lewisii Gould. Neverita recluziana Petit. Norrisia norrisii Sowerby.

Ocinebra barbarensis Gabb. Ocinebra foveolata Hinds. Ocinebra interfossa Carpenter. Ocinebra keep Arnold. 0(!inebra lurida Middendorf. Ocinebra lurida var. aspera Baird. Ocinebra lurida var. cncellina Pbilippi. lurida var. cerritensin Arnold. lurida var. nmnda ()cine))ra micheli Ford.

Ocinebra perita Hinds.

Ocinebra poulsoni Nuttall.

*OdoHtomia gouldii

*OdoHtomia nucifonnis var. avellana Carpenter.

()<loHtomia tenuis Carpenter.

bipli(;iita Sowerby.

Olivella intorta

Olivella juMlroana Conrad.

Opalia borealis (Jould.

Opalia <Tenit<)idtH var. Carpenter.

PatrhyiKjma Martyn.

Paludestrina curta

stokesi Arnold.

Pbasianella compta Gould. *Phy8a heterostropha Say. Pisania fortis Carpenter. Planorbis tumidus Pfeiffer. Planorbis vermicularis Gould. Pleurotoma (Borsonia) bartschi Arnold. Pleurotoma (Dolicbotoma) carpenteriana (jabb. Pleurotoma (Dolicbotoma) cooperi Arnohl. ♦Pleurotoma (Borsonia) dalli Arnold. ♦Pleurotoma (Borsonia) hooveri Arnold. ♦Pleurotoma (Leucosyrinx) pedroana Arnold. Pleurotoma Grabb. ♦Pleurotoma (Drillia) renaudi Arnold. ♦Pleurotoma (Spirotropsis) smithi Arnold.

Pleurotoma (Dolicbotoma) tryoniana Gabb. Pomaulax undosus Wood.

Priene oregonensis Redfield.

Puncturella cucullata Gould.

♦Puncturella galeata Gould.

Purpura crispata Cbenmitz.

Purpura saxicola Valenciennes.

Pyramidella var. variegata Carpenter.

Ranella californica Hinds.

Rissoa acutelirata Carpenter.

Scala bellastriata Carpenter.

Scala crebricostata Caqenter.

Scala bempbilli Dall.

Scala hindsii

Sirala indianonim Carjienter.

Scala tincta

♦Sella assimilata C. B. Adams.

Serpulorbis s(]uamigerus Car[)enter.

Sigaretus debilis Gould.

kellettii Forbes.

Spiroglyphus lituella Morch.

♦Styliferina tenuisculpta Carpenter.

Taranis strongi Arnold.

Terebra (Aciis) simplex

♦Thalotia caffea Gabb. ' Tornatina cereals Gould.

Tornatina culcitella Gould.

Tornatina harpa Dall.

Triforis adversa Montague.

Trivia california4i (iray.

Trivia solandri Gray.

Tritonium gibbosus Broderip.

Tropbon ( Boreotropbon ) crritensis Arnold.

♦Tropbon ( lioreotropbon ) gracilis Perry.

Tropbon (Boreotropbon) multicostatus Escbscboltz.

♦Trcjpbon orpbeus var. precursor Arnold.

Tropbon (Boreotropbon) pedroanus Arnold.

Geologic Ea.Nge Of Califobnia Pecten8.

List of San Pedro formation (PleisUjcme) fomla — Continued.

GASTEROPODA — Continued.

Trophon Boreotrophon ) pacificus Dall.

Trophon stuart Smith.

Trophon (Boreotrophon) triangulatUH Carpenter. *Turbonilla adler Dall & Barth.

Turbonilla arnoidi Dall Bartsch. Turbonilla aurantia Carpenter. Turbonilla crebrifilata Carpenter.

Turbonilla gibbosa Carpenter. Turbonilla laniinata Carpenter. Turbonilla latifundia Dall & Bartch. Turbonilla lowei Dall & Bartech. Turbonilla muricata Gould. ♦Turbonilla pentalopha Dall & Bartech. eimilimis C. B. Adamt?. Turbonilla Htearneii Dall & Bartech.

CIA8TEROPODA — fOUtiUUed.

Turbonilla subcuspidata Carpenter. Turbonilla tenuicula Gould.

Turbonilla torquata Gould.

Turbonilla torquata var. stylina Carpenter. Turbonilla tridentata Car|)enter. Turritella ooojeri Carpenter.

Turritella jewetti Carpenter.

Vermicularia, sp. indet. Vitrinella willianiHoni Dall. Volvarina varia Sower by.

Volvula cylindrica Carpienter.

Pisces.

Urolophus halleri Cooper(?)

Geologic Range Of California Pectens.

Range of species and varieties. [? shows limit* somewhere between which the species belongs.]

Recent. Pliocene. Miocene.

TU'ito. San Mer- Purlsi- San Monte- Vaqueiiving.i Pedro, ced. ma. ' Pablo. rey. I ros.

Pecten: '

alaekensis Dall '

andersoni n. sp tt ,

var. barkerianue n. var '

aehleyi n. sp ' tt

auburyi n. sp ;

bartschi n. sp : ttt ,

bellusConrad , ' tt '

bellilamellatufi n. sp , tt

Oligocene.

San Lorenzo.

Eocene.

Tejon.

I i tt ;

bowers n. sp , j ????

branneri n. sp 1 tt

calkinsi n. sp i '

carrizoensis n. sp

caurinus Gould

cerrosensis Gabb

var. mendenhalli n. var.. circularis Sowerby

var. tequisulcatus Cpr

clallamensis n. sp

coalingaensis n. sp

cooperi n. sp

coosensis Shumard

I ???? ?? '

tt ;

tt I tt

36 Tebtiary And Quaternary Pecten8 Of California.

LiitofSiiu Pedro formation Continuel.

QAOTEROPODA— (iA8TEROPODA-fOntinUed.

Margarita optabilis var. nodosus Arnold. Margarita parcipicta var. pedroana Arnold. Marginalia jewettii Carpenter. Megatebennus bimaculatus Ball.

Mitra maura Swainson.

Mitramorpha filosa Carpenter. *Mitramorpha intermedia Arnold. Monocerofl engonatum Conrad. Monoceros lapilloides Conrad. Mopalia ciliata Sowerby.

Murex (Pteronotue) festivijs Hinds.

Murex (Pterohytis) foliatus Martyn.

Murex (Pterohytis) nuttalli Conrad.

Murex (Chicoreus) leeanus Dall.

Murex (Cerostoma) monoceros Bowerby.

Murex trialatus Sowerby.

Nassa californian

NasHa cerritensis Arnold.

Nassa fossata Gould.

Nassa insculpta Carpenter.

Nassa mendica Gould.

Nassa niendica var. cooiKjri Forbes.

Nassa Hinds.

Nassa tegula Reeve.

Nassa versicolor var. hooveri Arnold.

Natica clausa Broderip & Sowerby. Natica (Lunatia) lewisii Gould. Neverita recluziana Petit. Norrisia norrisii Sowerby.

Ocinebra barbarensis Gabb. Ociuebra foveolata Hinds. Ocinebra interfossa Carpenter. Ocinebra keep Arnold. Ocinebra lurida Middendorf. Ocinebra lurida var. aspera Baird. Ocinebra lurida var. cancelling Philippi. Ocinebra lurida var. cerritensin Arnold. *Ocinebra lurida var. Carpenter. ()cine))ra micheli Ford. Ocinebra perita Hinds. Ocinebra iMulsoni Nuttall. *Odostomia gouldii Carpenter. *Odostomia nuciformis var. avellana (-arpeuter. Odostomia tenuis Carpenter. Olivella biplicata Sowerby. Olivella intorta Carpenter. Olivella pedroana Conrad. Opalia boreal is Gould. Opalia crenitoidt var. insculpta Carpenter. Pachypoma injvquale Martyn. Paludestrina curta Arnold. Paludeetrina stokesi Arnold.

Phasianella tcimpta Gould- *PliyBtt heleroetropha Hay, Fisiiuiu fortis Carpenter. Plan orb in tumiduH T*feiHer. Planorbis vennicularia Gould. Pleurotoma ( Boreonia] bartechi Arnold, Pi*'urotoma ( Dolichotoma ) carpenteriana Gabl*. Pleurotoum [ Dolichotoma) cim:j fieri Arnold, *Pleurotatnft (Borsonia) dalH Arnold. *Pleurotma (Borsonia) Arnold* ' *Pleurotoma (Leiicosyrinx ) Arnold. Pleurotoma Gabb, ♦Pleurotjnm (Driilia) renaudi Arnold, *Pleurotoma {Spirotropis) nmithi Arnold. Pleurotoma (Dolichotoma) t ryoniana Gabk Pomaukx Wotxl. Priene field. Puncture! lu cticullata Gould. *Panctuiiella gales ta Gould. criflpata Chemnitz, T'urpura eaiic<>la Valenciennes?* Pyrainidella cnit var. variegala Gai'penter* Raiiella eaUfornica Kinds, Rissoa acutelirata Carpenltn Scala bellah:triata Scala crebricoftUita Hrala hempbilli Ihiil. S.'ata hindsii Car|.H;nter. St-ala iudianorum Ciir(>enter. Sfala tincta *Seila assiinilata B. Adams, Serpiilirbia Rjuamigeniii BiiBirptus debilL* i would. 8ijihf.iualia kellettii Forbes. 8pirojrlyphu?f lilueUa Morch. *ityliferiim temibwulpta Carpenter. Taranis wtrongi Arnold. Tercbm (Aoua) slmpleic Carplte;* Thalotia caffea Gabb. ' Tornutina cerealifl Gould. Tornatiua culcitelk GonUi Tonmtina Imrpa Dall* friforiB ad versa Mont Trivia caUfoniica Gmy Trivia solaodri Grav. Tritomum giblxMus Trophon ( Boreotrophon riirriteiiofe AltwiiL ( ) gradii PWry, Tniphoil iiioltiWiilM

Oeoi-Ogic Ea.Nge Of Califobnia Pecten8.

List of San Pedro formation {PleiMijcnie) foiails — Continued.

GASTEROPODA — Continued.

Troplion Boreotrophon ) pacificus Dall.

Trophon stuart Smith.

Trophon (Boreotrophon) triangulatue Carpenter. *Turbonilla adler Dall & Bart44ch. *Turbonilla arnoldi Dall & Bartsch. Turbonilla aurantia Carpenter.

Turbonilla crebrifilata Carpenter.

Turbonilla gibboea Carpenter. Turbonilla laniinata Carpenter. Turbonilla latifundia Dall & Bartsch. Turbonilla lowei Dall & Bartsch. Turbonilla niuricata Gould. ♦Turbonilla pentalopha Dall & Bartfjch. Turbonilla similimis C. B. Adams. Turbonilla stearneii Dall & Bartsch.

GASTEROPODA — COUtiuued.

Turbonilla subcuspidata Carpenter. Turbonilla tenuicula Gould.

Turbonilla torquata Gould.

Turbonilla torquata var. stylina CarpenUr. Turbonilla tridentata Carpenter. Turritella cooperi Carpenter.

Turritella jewetti Carpenter.

Vermicularia, sp. indet. Vitrinella williamsoni Dall. Volvarina varia Sowerby.

Volvula cylindrica Car|)enter.

Pi8Ce.S.

Urolophus halleri

Geologic Range Of California Pectens.

Range of species and varieties. [? shows limits somewhere between which the species belongs.]

Recent.

Pleisto-

Pliocene.

Miocene.

iTivinir San Mer- Purisl-

San Monte- 1 Vaque- Pablo. I rey. I ros.

Pecten: ' I

alaskensis Dall , '

' andersoni n. sp tt

var. barkerianus n. var ! ,

ashley n. sp tt ,

Oligocene.

San Lorenzo.

Eocene.

Tejon.

Martinez.

auburyi n. sp

hartpchi n. sp

lieiluB Conrad

belUlamellattie n. ep.

bratiueri u.

Llktiufi 11- ipp

tttfrixmnub ep

enurliitia Gould

cmtMisiwit Gabb . . .

1 tt !

tt !

90?9

I ' I.

tt 1

' ] n?? j ?? I

I tt i-

0997 I 999?

Tertiary And Quaternary Pecten8 Of California.

Range of speeies and mrieties — Continueil. I? ihowK limits Mumewhere between which the Mpecies belongs.]

Recent.

Living.

Pleistocene.

San Pedro.

Pliocene.

Mer- Purisiced. I ipa.

Miocene.

San Monte- 1 Vaque- Pablo. I rey. , fob.

Oligo- 1

Eocene.

San Lo-

Tejon.

Martinez.

Pecten — Continual.

rrassicanloConraii I

var. hamiltoni n. var ????

Dall I : i i

deperti Conrad I ; ???? ???? '????

diegensis Dall

discus Conrad

eldridgei n. sp

estrellanos Conrad

var. catalina* n. var

var. terminus n. var ,

exiavatus Anton

fut-anusDall ; ???? ????

giganteus CJray I [ :

hamlini n. sp ???? ????

...; tt j tt

-..!

I

hastatus Sowerby

var. albidus Dall n. var..

var. hericiuH ( Jould ,

var. hindsii Carpenter . . .

var. navarchus Dall

var. strategus Dall

.

,

i

tt tt tt

tt

healeyi n. sp : .-

hemphilli Dall ! tt

interraciiatus Gabh

islandicus Midler ' j

jordan Arnold i

keep n. sp

tt tt

landesi n. sp , ;

latiauritus Conrad tt ; ; I

var. cerritensis n. var

var. delosi n. var

var. fuciwlus Dall

var. nionotinieris Con . . .

lawsoui n. sp i

h'contei n. sp i

lompicoensis n. sp i I

lonipooensis n. sp I '

I.

Geologic Range Of California Pecten8.

Range of species and rariefitx — Continued. [; shows limits wnnewhcre Ix'twetMi which tht- sixcies belong.]

iR--/Jci.r'

Pliocene.

iTi„j__ San I Mer- I Living. Pedro, oed.

inirisima.

Miocene.

Oligoeene.

?>K'eiie.

San j Monte-, Vaq ue- iSan Lo- t,,, i Marli- Pablo. rey ros. I renzo. nez.

Pet'ten — Continued. 1 '

magnolia Conrad , !

merriami n. hj)

miguelensin n. sp

neahensiH n. sp ' Trr TTT!

nutteri n. sp tt ,

opuntiaDall tt I tt ; i

oweni n.. sp i

pabloensis Conrad i

palmeriDall tt+t

panneleei Dall... +t ;

paucicoftatu8 t+t

Gabb j tt

'

perrinin. sp ' TT! I

proaviLS n. sf*

propatulus(\)nrad rm TTTi rTT

purisnnaensis n. sj) ,

randolph Dall

var. tillaniookensiH n. var.

rivers n. sp tt tt ' i

Hancta?cruzensi8 n. sp t ttt

sespeensis n. sp ,

var. h ydei n. var ,

stanfordensis n. sp TTf ,

stearnsii Dall tt

subnodosus Sowerby

turneri n. sp

vanoouverensis Whiteaves . . . ,

vaujiThani n. sp I

voatohii (iabb tt i

vogdesi n. sp 'rT!? '!rr! ' ;

washburnei n. sp

watts n. sp

Var. niorani n. var

waylandi n. sj) i

tt ! tt

40 Tertiary And Quaternary Pectens Of California.

Summary of range of species and varieties.

Species foand in the Eocene 4

Species found only in the Eocene 4

Species transitional between the Eocene and Oligocene None.

Species found in the Oligocene 5

Species found only in the Oligocene None.

Species transitional between the Olijjocene and Miocene 5

Species found in the Miocene 32

Varieties found in the Miocene 6

Species found only in the Mifx*ene 23

Varieties found only in the Miocene 5

Species doubtfully Miocene 1

Spt'ies transitional letween the Miocene and Pliocene 4

Varieties transitional l.)etween the Miocene and Pliocene 2

Species doubtfully transitional 1

Species found in the Pliocene 31

Varieties found in the Pliocene 6

Species found only in the Pliocene 23

Species doubtfully Pliocene 2

transitional between the Pliocene and Pleistocene 7

Varieties transitirmal between the Pliocene and Pleistwene 3

Species doubtfully transitional 2

Species found in the Pleistocene 11

Varieties found in the Pleist<>cene 9

Species found only in tlie Pleistocrene 1 (?)

Varieties found only in the Pleistocene 1

Species transitional between Pleistocene and Recent 9

Varieties transitional between Pleistocene and Recent 8

Species found in the Recent fauna 15

Varieties found in the Recent fauna 10

Species found only in the Recent fauna 7

Varieties found only in the Recent fauna 2

S|)ecie8 found from Recent to Pliocene fauna (1 doubtful ) 6

Varieties found from Recent to Pliocene fauna 4

Species found from Recent Miocene fauna 1

Varieties found from Recent to Miocene fauna 1

Part Ti. Synopsis And Descriptions Of Subgenera And Species.

Synopsis Of Subgenera And Species.

Page.

Class PELEOYPODA 45

Order PRIONODESM ACE A 46

Superfamily PECTIXACEA 45

Family PEcriNiDiE 45

Genus Pecten Mi'iller 46

Subgenus Pecten h. s. Miiller 48

Patinopecten Dall 48

Dall 49

Chlam ys Bolten 49

Ly Conrad 49

vEquipecten Fischer 49

Plagioctenium Dall 60

Pseudamusium H. and A. Adams 50

Amusium Bolten 50

Propeamusium Gregorio 50

Hinnites Defrance 50

Eocene Pectens 51

P. (Chlauiys) calkingi n. sp 51

P. (Chlaniyi?) landesi n. sp 51

P. (Chlamys) proavus n. sp 52

P. ( Propeamusium) interradiatus Gabb 53

Oligocene Pectens 54

P. ( Pecten ) sanctfecruzensis n. sp 54

P. (Chlamys) branneri n. sp 55

P. (Pseudamusium ) pecjthami Gabb 56

P. (Propeamusium) clallamensis n. sp 57

P. (Propeamusium) waylandi n. sp 58

Miocene Pectens 59

P. (Pecten ) carrizoensis n. sp 59

P. (Pecten) keep n. sp 60

P. (Pecten) sanctiecruzensis n. sp. (persists from Oligocene) 60

P. (Patinopecten) coosensis Shumard 61

P. (Patinopecten) dilleri Dall (?) 62

P. (Patinopecten ) oweni n. sp 63

P. ( Patinopecten ) propatulus Conrad 64

P. (Chlamys) branneri n. sp. (persists from Oligotene) 55

P. (Chlamys) fucanus Dall 66

P. (Chlamys) hamlini n. sp 67

P. (Chlamys) hastatus var. hericius Gould 110

P. ( Chlamys ) nutteri n. sp 67

P. (Chlamys) sespeensis n. sp 69

P. ( Chlamys ) sespeensis var. hydei n. var 69

The description of each species will be found under the heading? of the epoch in which the species is first known to occur. Any species persisting into a following epoch will be listed in the synopsis also under the heading of the latter with an explanatory note.

42 Tertiary And Quaternary Pecten8 Of Oalifornia.

Claas PELE0YP0DA-O>,ntinued.

Order PRIOXO DESMACE A— Cont'neil. Saperfamily PECTIXACEA— Family Pbctin'id.e — Continaed.

Genus Pe/ien Muller — C'ontinueii.

Miocene Pectens — Continued. page.

P. ( LyroiJet'ten) twwerei n. sp 70

P. (Lyropecten) crassicardu Conral 71

P. ( ) crassicardo var. hamiltoni n. var 73

P. ( Lyropecten ) estrellanuM Conrad 74

P. ( Ly roiKH'ten ) ettrellanus var. catalime n. var 76

P. Lyropecten I eetrellanus var. terminus n. var 77

P. I ) magnolia Conrad 77

P. ( Lyropecten) miguelensis n. sp 79

P. Lyropecten ) jnirrini n. sp 80

P. ( Lyropecten ) vaughani n. sp 81

P. ( Plagioctenium ) andersoni n. sp 82

P. ( Plagioctenium ) andersoni var. barkerianus n. sp 83

P. ( Plagioctenium) cerrosnsii* var. mendenhalli n. var 84

P. ( Plagioitenium ) deserti Connwl 85

P. ( Plagioctenium ) discus Conrad 86

P. ( Plagioctenium ) eldridgei n. sp 87

P. [ Plagioctenium ) ncahensis n. sp 87

P. ( Plagioctenium ) pabloensis Connul 88

P. ( Psendamusium) lompicoensis n. sp 89

P. ( Psewlamusium ) perlroanus Trask 90

P. ( Psendamusium) peckhami Gabb (persists from Oligocene) nO

P. ( Proijeamusium ) claliamensis n. sp. from Oligocene) 57

P. ( Proiteamusium ) stanfonlensis n. sp 91

P. ( ) waylandi n. sp. ( persists from )lii;ocene) 58

P. ( Amusium ) lom]>ocensis n. sp 92

P. llinnites) giganteus iray 93

Pliocene Pei-tens 94

P. ( Pecten ) anbury i n. sp 94

P. ( Pecten ) Ijellus 95

P. ( Pecten) coalingaensis n. sp 97

P. (Pe<-ten) hemphilli Dall 97

P. ( Pecten ) lecontei n. sp 98

P. ( Pecten ) merriami u. sp 99

P. (Pecten) steamsii 100

P. (Pecten) vogdesi n. sp 100

P. ( Patinopecten ) caurinus Gould 101

P. ( Patinopecten ) dilleri Dall ( from the M iocciie ? ) 62

P. ( Patinopecten) healeyi n. sp 103

P. ( Patino|)eaten ) oweni n. sp. (ix*resists from 63

P. ( Patinopei'ten) purisimaensis n. si> 105

P. ( Patinopecten ) turneri n. sp 106

P. ( XcKli|)eaten ) veat<'hii Gabb 106

P. (Chlamys) n. sp 107

P. (Chlamys) belli lamellat us n. sp 108

P. (Chlamys) hastatus Sowerby 108

P. (Chlamys) hastatus var. hericius Gould (persists from Miocene)... 110

P. ( Chlamys) hastatus var. hindsii Carpenter Ill

P. ( Chlamys) hastatus var. navarchus Dall 112

P. (Chlamys) hastatus var. strategus Dall 113

P. (Chlamys ) islandicus Muller 113

Synop818 Of Subgenera And Species. 43

ClaflB PELEOYPOD A— Continued.

On!er PRIONODESMACEA-Continued. Superfamily PECTINACEA— Continued. Family Pbctinidjb — Continued.

Genufi Pecteii Muller — Continued.

Pliocene Pectens — Continued.

P. (Chlamys) jordan Arnold 114

P. (Chlamys) latiaurituH Conrad 115

P. (Chlamys) lawson n. up 117

P. (Chlamys) nutteri n. up. (persisU* fnun Micnrene) 69

P. (Chlamys) opuntia Dall 118

P. ( Chlamys) parmeleei Dall 119

P. (Chlamys) washbumei n. sp 119

P. (Chlamys) watts n. sp 120

P. (Chlamys) watts var. moran n. var 121

P. (Lyropecten) aihleyi n. sp 122

P. (Lyropecten) estrellanun var. cataliim' n. var. from

Miocene) 76

P. ( Plagioctenium ) cerrosensis (labb 123

P. ( Plagioctenium ) circularis Sowerby (?) 125

P. ( Plagioctenium ) n. Hp 124

P. ( Pseudamusium) Trask (persists fnni Miocene) 90

P. (Propeamusium ) rivers n. sp 126

1*. ( Hinnites) giganteus Gray (persists from Miocene) 93

Pleistocene Pectens 127

P. ( Pecten) diegensis Dall 127

P. ( Pecten ) vogdesi n. sp. ( persists from Pliocene) 100

P. ( Patinopecten) (uranus Gould ( persists from Pliocene) 101

P. (Nf ulipetten ) subnodosus Sowerby 128

P. (Chlamys) hastatus Sowerby (persist from Pliocene) 108

P. (Chlamys) hastatus var. hericius Gould (persists from Miocene) .. 110

P. (Chlamys) hastatus var. hindsii Carpenter (persists from Pliocene) . Ill

P. (Chlamys) hastatus var. navarchus Dall (persists from Pliocene) .. 112

P. (Chlamys) hastatus var. strategus Dall (persists from Pliocene) 113

P. ( Chlamys) islandicus Miiller (persists from Pliocene) 113

P. (Chlamys) latiauritus Conrad (persist** from Pliocene) 1 15

P. ( Chlamys) latiauritus var. cerritensis n. var 129

P. ( Chlamys ) latiauritus var. delosi n. var 130

P. ( Chlamys) latiauritus var. fucicolus Dall 131

P. ( Chlamys ) latiauritus var. monotimeris Conrad 131

P. ( PlagicKtenium ) cinularis Sowerby (insists from 125

P. ( Plagioctenium ) circularis var. io<|uisulcatus 132

P. (I*ropeamiL*>ium ) alaskensis 13,3

P. (Propeamusium ) rivers n. sp. (persists from Pliocene) 126

P. ( Hinnites ) giganteus Gray ( persist' from Miocene) 93

Recent Pectens 134

P. ( Pecten ) diegensis Dall ( jiersists from Pleisto<*ene ) 127

P. ( Pecten ) excavatus Anton 134

P. (Patinopecten) caurinus Gould (persists from Pliocene) 101

P. subnodosus Sowerby (persists from Pleistocene) 128

P. (Chlamys) hastatus Sowerby (persists from Pliocene) 108

P. ( Chlamys ) hastatus var. albidus Dall n. var 136

P. (Chlamys) hastatus var. hericius Gould (persists from Miocene) .. 110

P. (Chlamys) hastatus var. hindsii Carptnter from Pliocene) . Ill

P. (Chlamys) hastatus var. navarchus Dall from Pliocene).. 112

P. (Chlamys) hastatus var. strategus Dall ( persists from Pliocene) 113

Tebtiaby And Quaternary Pectbn8 Op California.

LiM of Sail Pedro (PieiMocefie) /ohsUh — ContimnMl. — continueil. pelbcypdda — (Continued.

Mactra exoleta Gray.

Mactra hemphilli Dall.

Metis alta Conracl.

fomicatus Carpenter.

Modiolufl reitus Conrad.

*Moerella salinonea Carpenter.

*Mytilinieria nuttalli Conrad.

Mytilufl edulia Linn.

*Neaira pectinata Carpenter.

*\ucla (Acila) castrensis Hinds.

Nucula suprastriata Carpenter.

Ostrea lurida Carpenter.

*Panomya ampla Dall.

Panopea generosa Gould.

Pecten caurinus Gould.

Pecten circularis Sowerby.

Pecten circularis var. tetiuipuUtatus Carpenter.

Pecten hastatus Sowerby.

*Pecten hastatus var. hericius (rould.

*Pecten hastatus var. strategus Dall.

*Pei*ten jordan Arnold.

Pecten latiauritus Conrad.

Pecten latiauritus var. cerritensiH n. var.

*Pecten latiauritus var. delosi n. sp.

Pecten latiauritus var. monotiuieris Conrad.

Peiten subnodonus Sowerby.

Pecten vogdesi n. sp.

Periploma argentaria Conrad.

Petricola ciirditoides Conrad.

Petricola (Petricolaria) cognata C. B. Adams.

Petricola denticulata Sowerby.

Phacoides (-f Lucina) acutilineatus Conrad.

Phacoides (4- Lucina) californicus

Phacoides ( j-Lucina) tenuisculptus Caqxnter.

Pholadidea penita Conrad.

Platyodon cancellatus Conraci.

Pododesmus (Monia) niacroHchisnia Dehayes.

*Protocardia oentifilosa Carpenter.

Psainmobia tnlentula Gabb.

♦Psephia nalinonea Carpenter.

Rupellaria lamellifera Conrad.

Sanguinolaria nuttalli Conrad.

Saxidonuis gracilis (rould.

Seniele decdsa Conrail.

Seniele pulchra Sowerby.

*Semele pulchra var. niontereyi Arnold.

*Septifer bifurcatus Conrad.

Siliqua lucida Conrad.

Siliquii patula Dixon var. nuttalli Conrad.

Solen sicariui* Gould.

Spisnla catillifoniiis Conrad.

S])isula falcata Gould.

Tagelus califomiauus Conrad. Tapes ladneata Carpenter. Tapes tenerriiua Carpenter. Tellina bodegensis Hinds. Tellina idje Dall. Tellina rubescens Haidey. *Thracia trapezoides Conrad. *Thyasira gouldii Philippi. Tivela crassatelloides Conrad. Tresus nuttalli Conrad. Venericardia barbarensis Steams.

Venericardia ventricosa Gould. Venus tantilla Gould (Psephis id. ). Venus (Chione) fluctifraga Sowrby.

Venus (Chione) gnidia Broderip and Sowerby. Venus (Chione) neglecta Sowerby. Venus (Chione) simillima Sowerby. Venus (Chione) succincta Valencifcnne.

Verticordia novemcostata Adams and R€ve. Yoldia cooperi Gabb.

*Yoldia scissurata Dall. Zirphaea gabbi Tryon.

(Gasteropoda.

depict Gould.

Acnisea insessa Hinds.

Acniiea instabilis Gould.

Acmiea mitra Eschscholtz.

Acnisea {laleacea (iould.

Acmcea delta Eschscholtz.

Acmaea spectrum (Nuttall) Reeve.

Actajon (Rictaxis) punctoccelata Carpenter.

Actseon traskii Stearns.

Admete gracilior Carpenter.

Amalthea antiquata Linn. (Hipponyx id. ) Amalthea cranioides

Amalthea tuniens Carpenter. Amphissa corrugata Reeve.

Amphissa ventricosa Arnold. Amphissa versicolor Dall. Bela fidicula Gould.

Bela sanctse-monica? Arnold. Bittium asperum Gabb.

Bittium califomicum Dall and Bartsch Bittium filosum Gould.

Bittium quadrifilatum Carpenter. Bittium rugatum Bittium williamsoni Arnold. Bulla punctulata A. Adams. Bulla quoyi Gray.

Cadulus fufiiformis Sharp and Pilsbry. Caecum californicum Dall.

Pleistocene Formations.

Littt of San Pedro formniion ( Plt'iMoctnie) j'ossih — Continued.

— continiieil.

Oeciim civbricinctuni CariHinter.

Ca*cum inaguuin Stearns. Calliostoma annulatum Martyn. CalliosUma ranalirulatuni Martyn. CallioKtonia costatnin Martyn. Calliostoma geinniiilatuni Carjienter. Calliostoma tricolor Gabb.

Cancel laria (labb.

Cancellaria crawfordiana Dall.

Cancellaria tritonidea (rabb.

Ccritbidea californica Haldemann.

Chloroatoma aureotinctnm Forbes.

Cblorostoma brunneum Philippi.

Cblorostoma funebrale A. Adams.

Cblorostonia funebrale var. subapertum

Cblorostoma gallina Forbes.

monterey Kiener.

Chlorastoma pulligo Martyn (Phorous id. ).

Cblorostoma (Ompbalius) viridulum var. ligula-

tum Menke. Chorus iKjleheri Hinds, ''hrysodonms rectirostris Carpenter. *Chrysodonnis tabulatus Bainl. Clathurella conradiana (xabb. *Columbella (Astyris) californian Gaskoin. Cohimlella (yEsopus) chrysalloidea Carpenter. C'olumbella (Astyns) gausapata (iould. (Astyris) gausapata var. carinata

Hinds. Columbella ( Anachis) minima Arnold. (.Esopus) oldroydi Arnolci. Columljella solidula var. pneoursor Arnold. Columbella (Astyris) tuberosa Carpenter. Conns californicus Hinds. Coralliophila nux Reeve. *Crepidula aculeata (Jmelin. Crepidula adunca Sowerby. Crepidula dorsata Bnxierip. Crepidula princeps C/onrad. Crepidula onyx Sowerby. Crepidula rugosa Xuttall. Crucibulum spinosum Sowerby. *Cryptochiton stelleri Middendorf. (\dicbna alba Brown. Cypnea spadicea Gray. *Cytbara !)ranneri Arnold. Dentalium indianorum Carpenter. Dentalium neohexagonum Sharp and Pilsbry. Dentalium iweudohexagonum Dall. Dentalium semipolitum Broderip and Sowerby.

Diastoma, sp. indet. Drillia cancel lata Carptmter.

(iAsTERopoiA — (continued.

Drillia hemphilli Stearns.

Drillia inert is Hinds.

Drillia inermis var. penicillata ( -carpenter.

Drillia johnsoni Arnold.

Drillia merriami Arnold.

Drillia montereyensis Stearns. Drillia pudica Hinds.

Drillia torosa Prato colum!)ella Menke.

Eulima falcata Carpenter. Kulinia hastata Sowerby. Eulima micans Carpenter. Euplcura muricifonnis Broderip. Eupleura muriciformis var. curta .\niold. Fissuridea Kschscholtz. Fisfiuridea injeijualis Sowerby. Fissuridea murina (Carpenter) Dall. Fissurella volcano Reeve.

Fusus barbarensis Trask.

Fusus luteopictus Dall.

Fusus robustus Trask.

Fusus rugosus Trask (=F. amoldi Cossmann).

(Jadinia reticulata Sowerby.

( Talerus mammillaris Broderip.

Haliotis fulgens Philippi.

Haminea virescens Sowerby.

Helix (Epiphragmophora) sp. indet.

Isapis fenestrata Carpenter.

Isi;hno(;hilton regularis Car{)enter.

I vara turricula (Carpenter) Dall and Bartsch. Lacuna compacta Carpenter.

Lacuna |)orrecta Carpenter. Iacuna solidula (Loven) Carpenter. *Lamel laria steamsii Dall. Leptothyra bacula Leptothyra crpenteri Pilsbry.

lA?ptothyra jmucicostata Dall. Litorina planaxis (Nuttall) Philippi. Litorina scutulata (iould. Lucapina crenulata Sowerby. Lucapinella callomarginata Carjjenter. Macron kellettii A. Adams. MaiTon lividus A. Adams. Mangilia angulata Carpenter. Mangilia booveri Arnold.

Mangilia interfo.sa var. {>edroana Arnold. Mangilia interlirata Stearns.

Mangilia oldroydi Arnold.

Mangilia painei Arnold.

Mangilia sculpturata Dall. Mangilia striosa C. B. Adams. Margarita optabilis var. knechti Arnold.

Tebtiary And Quaternaby Pe0Ten8 Of California.

List of Situ Pedro formation (Pleiatocene) fomh — Ccmtiniie*!.

Gasteropoda —

Margarita optabilis var. nodosus Arnold. Margarita parcipicta var. pelroana Arnold. Maiiginella jewettii Carpenter. Megatebenuus bimaculatus Dall.

Mitra maura Swainson.

Mitramorpha filoea Carpenter. *Mitramorpha intermedia Arnold. Monocerofl engonatuni Conrad. Monoceros lapilloides C-onrad. Mopalia ciliata Sowerby.

Murex (Pteronotue) feetivijs Hinds.

Murex (Pterohytis) foliatus Marty n.

Murex (Pterohytis) nuttalli Conrad.

Murex (Cbicoreus) leeanus Dall.

Murex (Cerostoma) monoceros Sowerby.

Murex trialatus Sowerby.

Nassa californian Conrad.

Nasa cerritensis Arnold.

Nas8a foBsata Gould.

Nassa insculpta Carpenter.

Nassa mendica (70uld.

Nassa mendica var. cooperi Forbes.

Nassa perpinguis Hinds.

Nassa tegula Reeve.

Nassa versicolor var. hooveri Arnold.

Natica clausa Broderip & Sowerby. Natica (Lunatia) lewisii Gould. Neverita recluziana Petit. Norrisia norrisii Sowerby.

Ocinebra barbarensis Gabb. Ocinebra foveolata Hinds. Ocinebra interfossa Carpenter. Ocinebra keep Arnold. Ocinebra lurida Middendorf. Ocinebra lurida var. aspera Baird. Ocinebra lurida var. cancelling Philippi. Ocinebra lurida var. cerritensis Arnold. *Ocinebra lurida var. munda Ocinebra micheli Fonl.

Ocinebra perita Hinds.

Ocinebra poulsoni Nuttall.

*Odostomia gouldii Carpenter.

*Odostomia nuciformis var. avellana Carpenter.

Odostomia tenuis Carpenter.

Olivella biplicata Sowerby.

Olivella intorta Carpenter.

Olivella pedroana Conrad.

Opalia boreal is (iould.

Opalia crenitoides var. insculpta Carpenter.

inaMjuale Marty n.

Paludestrina curta Arnold.

Paludestrina stokesi Arnold.

(iASTEROPODA — contiuued.

Phasianella compta Gould. *Physa heterostroplia Say. Pisania fortis Carpenter. Planorbis tumidus Pfeiffer. Planorbis vermicularis Gould. Pleurotoma (Borsonia) bartschi Arnold. Pleurotoma (Dolichotoma) carpenteriaua Gabb. Pleurotoma (Dolichotoma) cooperi Arnold. *Pleurotoma (Borsonia) dalli Arnold. *Pleurotoma (Borsonia) hooveri Arnold. ♦Pleurotoma (Leucosyrinx) pedroana Arnold. Pleurotoma Gabb. ♦Pleurotoma (Drillia) renaudi Arnold. ♦Pleurotoma (Spirotropsis) smithi Arnold. Pleurotoma (Dolichotoma) tryoniana Gabb. Pomaulax undosus Wood. Priene oregonensis Redfield. Puncturella cucuUata Gould. ♦Puncturella galeata Gould. Purpura crispata Chemnitz. Purpura saxicola Valenciennes. Pyramidella conica var. variegata Carpenter. Ranella californica Hinds. Rissoa acutelirata Carpenter. Scala bellastriata Carpenter. Scala crebricostata Carpenter. Scala hemphilli Dall. Scala hindsii CariHjnter. Scala indianorum Cariienter. Scala tincta Carpenter. ♦Seila assimilata C. B. Adams. Serpulorbis squamigerus Car[)enter. Sigaretus debilis Gould. Siphonalia kellettii Forbes. Spiroglyphus lituella Morch. Styliferina tenuisculpta Taranis strongi Arnold. Terebra (Acus) simplex ♦Thalotia cffea Gabb. ' Tornatina cereals Gould. Tornatina culcitella Gould. Tornatina harpa Dall. Triforis ad versa Montague. Trivia californica (iray. Trivia solandri Gray. Tritonium gibbosus Broderip. Trophon (Boreotrophon) cerritensis Arnold. ♦Trophon (Boreotrophon) gracilis Perry. Trophon (Boreotrophon) multicostatus ch-

8<'holtz. ♦Trophon orpheus var. precursor Arnold. Trophon (Boreotrophon) pedroanns Arnold.

GEOLOGIC KANGE Of CALIFOBNIA PECTEN8.

List of Pedro formation {PleiMocme) fotfsiU — Continued.

(GASTEROPODA — continued.

Trophon ( Boreotrophon ) pacificuH Dall.

Trophon stuart Smith.

♦Trophon (Boreotrophon) triangulatue Carpenter. *Turbonilla adler Dall & Bart4*oh.

Turbonilla arnoldi Dall & Bartech. Turbonilla aurantia Carpenter. Turbonilla crebrifilata Carpenter.

Turbonilla gibbosa Carpenter. Turbonilla laniinata Turbonilla latifundia Dall & Bartsch. Turbonilla lowei Dall & Bart4?ch. Turbonilla nuiricata Gould. pentalopha Dall & Bartech. Turlxjnilla Bimilimis C. B. Adams. Turbonilla steamsii Dall & Bartsch.

Turbonilla subcuspidata Carpenter. Turbonilla tenuicula Gould.

Turbonilla torquata Gould.

Turbonilla torquata var. stylina Carpenter. Turbonilla tridentata CarjKjnter. Turritella cooperi Caqjenter.

Turritella jewetti Carpenter.

Vermicularia, sp. indet. Vitrinella williamsoni Dall. Volvarina varia Sower by.

Volvula ( ylindrica Carpenter.

Pikes.

Urolophus halleri Cooper(?)

Geologic Range Of California Pectens.

Range of species and varieties. [? shows limitM somewhere between which the RiHicies belongs.]

Recent.

Pleisto-

Pliocene.

Miocene.

'living? San Mer-

San Monte- , Vaque- Pablo. rey. j ros.

Oligocene.

San Lorenzo.

Eocene.

Tejon.

Pecten:

alaskensifi Dall ' '

andersoni n. 8p , tt

var. barkerianus n. var. I

aehleyi n. sp tt tt+t ; !

auburyi n. sp ''

bartschi n. sp , i ,

bellus Conrad tt !

bellilamellatuH n. pp tt i i — I

????

branneri n. sp I tt

calkinhii n. sp i I

CArnzoensis n. sp

caurinus Gould

cerrosensis Gabb

var. mendenhalli n. var circularis Sowerby

var. tecjuisulcatus Cpr

clallamensis n. sp coalingaensis n. sp cooperi n. sp cooeensis Shumard

Tertiary And Quaternary Pecten8 Of California.

Range of species and rarielies — CJontinueil. I? HhuwM llmiis Homewhere between which the species belongs.]

Recent.! PJl

Peoten — ContinutHl.

crawsicanlo Conrad i

var. hamiltoiii u. var

diegensifl

I-

Pliocene.

Miocene.

! cene. rxx.iiu.

Merced.

Puriuiipa.

San Monte- 1 Vaque- Pablo. rey. , ros.

Uan Lo-!

Tejon.

dilleri Dall , ????

discus Conrad I ,

eldridgei n.

eMtrellanuH Conrad ;

var. n. var ,

var. tenninu.'< n. var ;

exmvatiifl Anton

Martinez.

tt

tt

!

f uoanufl Da 1 1 i j ? ? ? ?

giKanteuH (ray j +ttt I ' j

hamlini n. Hp ] ????

hastatUH Sowerby

var. albidiis Dall ii. var..

var. hericiiiH <Tould

j .

J.

tt

.

var. hindsii Carpenter...: ' j tt ' '

var. navarchiis Dall , , tt , ]

var. strategiiH Dall ' . ' tt

healeyi n. sp , i

hemphilli Dall ; tt I j '

interradiatus (iabb :

inlandiciiH Miiller ! !

jordatii Arnold ;

n. pp

landesi n. .p :

latiauritiis Conrad

var. cerritennis n. var

var. delosi n. var ,

var. fucR-oliiH Dall I

tt tt

var. nionotinieris Con . .

lawsoiii n. sp

lecontei n. Hp

lompicoennis n. sp

ionipocensis n. np

;

tt

Geologic Range Of California Pecten8.

Range of species and rar'wt'm* — Continued. [.' shows limits Homewhert' iM'tween which th' sjieoies bcloiigM.]

Recent.

Pleisto-

Mifjcenc.

OUgo- .

iniriai- , San ma. Pablo.

Monte- Vaque- San Lo- t„j„„ I Martirey ros. rcnzo. nez.

Pecten — Continued. I

magnolia Conratl ' '

merriami n. np

miguelensis n. sp

neahennis n. sp '???? T!T

nutter! n. 8p tt ,

opuntia Dall tt +t i

owenin.. sp t+tt '

IMibloensiH Conrad

palmeri Dall ttn '

parineleei Dall +t i

paucicoHtatus Carpenter

! tt

n. Hp I ;

proavus n. sp ,

projiatulus Conrad TTT 'rTT* ?!?!

purisiniaensin n.

randolph Dall

var. tillainookensis n. var . ttt

rivers n. HI) tt tt

Hanctiecruzenie n. np t ttt

Hespeennis n. sp

var. hydei n. var

stanfordennis n. sp T!

Htearnsii Dall tt

turneri n. sp ?? t+t+

vancoiiverensiH Whiteaves . . .

vaujrhani n. sp

veatchii ( Jabb tt

vogdesi n. sj) 'rm Trr j ;

washburnei n. sp

I 1 I I I !

watts 11. Hp tt+t '

Var. niorani n. var

wavlandi n. np tt , tt

40 Tertiary And Quaternary Pecten8 Of California.

Summnrif of range of specie* and rnrieties.

jpecie* in the Eocene 4

foond only in the Eocene 4

Spet-iee tran>-itionai Ijetween the Eocene and Oligocene None.

Species* found in the 5

Species found only in the Oligocene None.

Speciee transitional the Oligocene and Miocene 5

Species found in the Miocene 32

Varieties found in the Miocene 6

found only in the Miocene 28

Varieties found only in the Miocene 5

Species doubtfully Miocene 1

transitional the Miocene and Pliocene 4

Varieties transitional the Miocene and Pliocene 2

Species doubtfully transitional 1

Species found in the Pliocene 31

Varieties found in the Pliocene 6

Species found only in the Pliocene 23

Species doubtfully Pliocene 2

Species transitional between the Plioi'ene ami 7

Varieties transitional between the Pliocene and Pleistocene 3

Species doubtfully transitional 2

Species found in the Pleistocene 11

Varieties found in the Pleistocene 9

Species found only in the Pleistocene 1 (?)

Varieties found only in the Pleistocene 1

Species transitional ltween Pleistocene and Recent 9

Varieties transitional >)etween Pleistocene and Recent 8

Species found in the Recent fauna 15

Varieties found in the Recent fauna 10

Species found only in the Recent fauna 7

Varieties found only in the Recent fauna 2

Species found from Recent to Pliocene fauna ( 1 doubtful ) 6

Varieties found from Recent to Pliocene fauna 4

S|)ecies found from Recent to Miocene fauna 1

Varieties found from Recent to Miocene fauna 1

Part Ii.

Synopsis And Descriptions Of Subgenera And Species."

Synopsis Of Subgenera And Species.

Class PELEOYPODA 45

Order PRIONODESMACEA 45

Superfamily PECTINACEA 45

Family Pectinid 45

Genus Pecteri Miiller 45

Subgenus Pecten s. e. Miiller 48

Patinopecten Dall 48

Nodipecten Dall 49

Chlamys Bolten 49

Lyropecten Conrad 49

iEquipecten Fischer 49

Plagioctenium Dall 50

Pseudamusiuin H. and A. Adani.s 50

Aniusium Bolten 50

Propeamusium Gregorio 50

Hinnites Defrance 50

Eocene Pectens 51

P. (Chlamys) calkinsi n. sp 51

P. (Chlamys) landesi n. sp 51

P. (Chlamys) proavus n. sp 52

P. ( Propeamusium) interradiatus (Tabb 53

Oligocene Pectens 54

P. (Pecten) sanctfecruzensis n. sp 54

P. (Chlamys) branneri n. sp 55

P. (Pseudamusium) peckhami Gabb 56

P. ( Propeamusium ) clallamensis n. sp 57

P. ( Propeamusium) waylandi n. sp 58

Miocene Pectens 59

P. (Pecten ) carrizoensis n. sp 59

P. (Pecten) keep n. sp 60

P. (Pecten) sanctjecruzensis n. sp. (persists from Oligocene) 60

P. (Patinopecten) coosensis Shumard 61

P. (Patinopecten) dilleri Dall (?) 62

P. (Patinopecten ) oweni n. sp 63

P. ( Patinopecten) propatulus Conrad 64

P. (Chlamys ) branneri n. sp. (persists from Oligocene) 55

P. (Chlamys) fucanus Dall 66

P. (Chlamys) hamlini n. sp 67

P. (Chlamys) hastatus var. hericius Gould 110

P. ( Chlamys) nutteri n. sp 67

P. (Chlamys) sespeensis n. sp 69

P. (Chlamys ) sespeensis var. hydei n. var 69

The description of each species will be found under the heading of the epoch in which the species is first known to occur. Any species persisting into a following epoch will be listed in the sjmopeis also under the heading of the latter with an explanatory note.

42 Tertiary And Quaternary Pe0Ten8 Of California.

Claas PELEOYPODA-<ntinued.

Order PRIONODESMACEA— Continued. Saperfamily PECTINACEA— Continued. Family Pectinid.e —

Genus Pedeii Muller — Continued.

Miocene Pecteus — ContinutKi. Page.

P. ( Lyrojiecten) bowerei n. sp 70

P. (Lyropecten) crassicArdo Conrad 71

P. ( Lyropecten ) crassicardo var. haiuiltoni n. var 73

P. (Lyropecten ) estrellanuH Conrad 74

P. (Lyropecten) estrellanus var. catalinije n. var 76

P. ( Lyropecten ) estrellanus var. terminus n. var 77

P. Lyropecten ) magnolia Conrad 77

P. ( Lyropecten) miguelensis n. sp 79

P. ( Lyropecten ) perrini n. sp 80

P. ( Lyropecten) vaughani n. sp 81

P. ( Plagioctenium ) andereoni n. sp 82

P. ( Plagioctenium ) andersoni var. barkerianus n. np 83

P. ( Plagioctenium) cerrosensis var. mendenhalli n. var 84

P. ( Plagioctenium ) dewrti Connwl 85

P. ( Plagioctenium ) discs Conrad 86

P. ( Plagioctenium ) eldridgei n. sp 87

P. ( Plagioctenium ) neahensis n. sp 87

P. ( Plagioctenium ) pabloensis Conrad 88

P. ( Pseudanmsium ) lompicoensis n. sp 89

P. ( Pseudaniusium ) ptrlroanu.s Trask 90

P. (Pseudaniusium) peckhami (iabb (persists from Oligocene) 50

P. (Propeanmsium) clallameusis n. sp. (persists from Oligocene) 57

P. (Pro|)eamusium ) stanfordensis n. sp 91

P. (Propeamusium) waylandi n. sp. (persists from Oliiiocene) 58

P. ( .Amusium ) lompocensis n. sp 92

P. ( Hinnites) giganteus (iray 93

Pliocene Pectens 94

P. ( Petten ) auburyi n. sp 94

P. ( Pecten ) liellus Conrad 95

P. ( Pecten ) coalingaensis n. sp 97

P. ( Pecten) hempbilli Dall 97

P. ( Pecten ) lecontei n. sp 98

P. (Pecten) merriami n. sp 99

P. (Pecten) stearnsii Dall 100

P. (Pecten) vogdesi n. sp 100

P. ( Patinopecten ) caurinus (rould 101

P. ( Patinopecten ) dilleri Dall ( from the M iocciie ? ) 62

P. ( Patinopecten) healeyi n. sp 103

P. (Patinopecten) oweni n. sp. (persists Irom Mioc*ene) 63

P. ( Patinope<'ten ) purisimaensis n. sp 105

P. ( PatinojHH'ten ) turneri n. sp 106

P. ( veatchii Gabb 106

P. (Chlamys) bartschi n. sp 107

P. (Chlamys) bellilamellatus n. sp 108

P. (Chlainys) hastatus Sowerby 108

P. (Chlamys) hastatus var. hericius Gould fmm Miocene)... 110

P. ( Chlamys) hastatus var. hindsii Carpenter Ill

P. ( Chlamys) hastatus var. navarchus Dall 112

P. (Chlamys) hastatus var. strategus Dall 113

P. (Chlamys ) islandicus Muller 113

Synopsis Of Subgenera And Species. 43

ClaflB PELEOYPODA— Continued.

Onler PRIONODESMACEArontinueil. Superfamily PECTINACEA— Continued. Family PEcrixiDiB — Continued.

Genus Pecten Miiller — Continued.

Pliocene Pectens — Continued. Pat'-

P. (Chlamys) jordan Arnold 114

P. (Chlamys) latiauritUH C-onrad 1 15

P. (ChlamvH) lawson n. np 117

P. (Chlamys) nutteri n. sp. from Miocene) 69

P. ( Chlamys) opuntia Dall US

P. (Chlamys) parmeleei Dall 119

P. (Chlamys) washburnei n. 1 19

P. (Chlamys) watts n. up 120

P. (Chlamys) watts var. moran n. var 121

P. (Lyropecten) ashley n. sp 122

P. (Lyropecten) e4trellanuH var. catalina* n. var. (iKrHist** from

Miocene ) 76

P. ( Plagioctenium ) cerrosensis Ciabb 123

P. ( Plagioctenium ) circularis Sowerby (?) 125

P. Plagioctenium ) coo|)eri n. sp 124

P. (Pseudamusium) {HKiroanus Trask (persists from Mio<*tne) 90

P. ( ProiHjamusium ) rivers n. sp 126

P. ( 1 linnites) giganteus Clray ( persists from Miocene) 93

Pleistocene Pectens 127

P. ( Pecton) diegensis Dall 127

P. ( Pecten ) vogdesi n. sp. ( persists from Pliocene) 100

P. ( Patinopecten) caurinus Crould (persists from Pliocene) 101

P. ( Ncxlipecten ) subnodosus Sowerby 128

P. (Chlamys) hastatus Sowerby (persists froiu Pliwene) 108

P. (Chlamys) hastatus var. hericius Gould (persists from Miocene) .. 110

P. (Chlamys) hastatus var. hindsii Carpenter (persists from Pliocene). Ill

P. (Chlamys) hastatus var. navarchus Dall (persists from Pliocene) .. 112

P. (Chlamys) hastatus var. strategus Dall from Pliocene).,.. 113

P. (Chlamys) islandicus Muller (persists from Pliocene) 1 13

P. ( ( 'hlamys ) latiauritus Conrad ( persists from Pliocene ) 115

P. ( Chlamys) latiauritus var. cerritensis ii. var 129

P. (Chlamys) latiauritus var. delosi n. var 130

P. (Chlamys) latiauritus var. fucicolus Dall 131

P. (Chlamys) latiauritus var. monotimeris Conrad 131

P. ( Plagioctenium ) cinularis Sowerby (persists from Pliocene) 125

P. ( Plagioctenium ) circularis var. uMiuisulcatus Caqienter 132

P. (Propeamusium ) alaskensis Dall 133

P. ( rivers n. sp. from Pliocene) 126

P. ( Hinnites) giganteus Gray ( persists from 93

Recent Pectens 134

P. ( Pecten ) diegensis Dall ( ixrsists ) 127

P. (Pecten) excavatus Anton 134

P. (Patinopecten ) caurinus Gould (persists from Pliocene) 101

P. (Nodipecten) subnodosus Sowerby (persists from Pleistocene) 128

P. (Chlamys) hastatus Sowerby ( from Pliocene) 108

P. ( Chlamys ) hastatus var. albidus Dall n. var IS6

P. (Chlamys) hastatus var. hericius Gould (|)er8ists from Miocene) .. 110

P. (Chlamys) hastatus var. hindsii Carpenter (persists from Pliocene) . HI

P. (Chlamys) hastatus var. navarchus Dall (persists from Pliocene).. 112

P. (Chlamys) hastatus var. strategus Dall (persists from Pliocene) 113

44 Tertiary And Quaternary Pecten8 Of California.

Class PELEOYPODA— Continued.

Onler PRIOXODESMACEA-oniinued, Superfainily PECTIXACEA— Continued. Family Pectixid— Continueti.

Genus Peden Muller — Continued.

Recent Peftens — Continueil. Pa.

P. (Chlamys) islandicus Muller (persists from Pliocene) 113

P. (Chlamys ) latiauritus Conrad (persists from Pliocene) 115

P. ( Chlamys) latiauritus var. delosi n. var. (persists from Pleistocene) . 130

P. (Chlamys) latiauritus var. fucicolus Dall from Pleistocene) . 131 P. (Chlamys) latiauritus var. monotimeris Conrad (fiersists from

Pleistocene ) 131

P. -Equipecten) palmeri Dall 136

P. ( Plagioctenium ) paucicostatus Carpenter 137

P. (Plagioctenium) circularis Sowerby (persists from Pliocene) 125

P. 'Plagioctenium) cinrularis var. tequisulcatus Carpenter (persists

from Pleistocene) 1 32

P. ( Pseudamusium ) davidsoni Dall 138

P. ( Pseudamusium ) randolph Dall 138

P. ( Pseudamusium) randolph var. tillamookensis n. var 139

P. ( Pseudamusium ) vancouverensis Whiieaves 140

P. ( Propeamusium) alaskensis Dall ( persists from Pleistocene) 133

P. ( Hinnites) giganteus Gray (persists from Miocene) 93

Unidentitiable Pectens 141

P. catilliformis Conrad (Miocene) 141

P. nevadanus Conrad ( Miocene) 141

P. ( Recent) 141

P. subcrenatus Carpenter ( Recent) 142

P. townsendi Gould (Recent) 142

Snutmnri/ of the snlrtjenera and

Number of subgenera represeutetl 11

Number of species represented 76

Old 8|)ecie8 36

New species 40

Num]>er of varieties reprt8ented 17

Old varieties 7

New varieties 10

Number of included in Pecten s. s 13

Number of species included in Patinopetrten 8

Number of species included in Nodipecten 2

Number of species in Chlamys 17

Number of varieties in Chlamys 11

Number of species included in Lyropecten 9

Number of varieties included in Lyropecten 3

Number of species in Equipecten 1

Number of species included in Plagioctenium 11

Number of varieties included in Plagioctenium 2

Number of species included in Pseudamusium 6

Number of varieties in Pseudamusium 1

Niunber of species included in Amusiuni 1

Number of species included in Propeamusium 6

of species included in Hinnites 1

Synopsis And Descriptions Of Subgenera And Species.

Descriptions Of Subgenera And Species.

Class PELEOYPODA.

Order PRIOXODESMACEA.

Superfamily PECTINACEA.

Family Pectinid.*:.

Genus Pecteii<' Miiller.

1776. Pecten (Klein, 1753) Miiller, Prodr. Zool. Dan., p. 248. 1778. Pedm Da ('osta, Brit. Conch., p. 14().

1798. Pectm Bolten, Mas. Bolt., p. 165.

1799. /Vcfi Lamarck, Prodr. d'un Nouv. Cla&s. Coq.,p. 88.

1898. PecUn Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, p. 689. Type, Ostrea maxima Linn.

GENUS PECTEX }ftLLEH.

"The shell of comprises two generally more or less discrepant valves, united along a long, straight hinge line by an inconspicuou.s ligament and a central strong resilium. A single rounded adductor leaves its impression pretty

Fig. \.~Pfcii:n nrctUnris Sowerby var. lequisulccUun Carpenter. Right valve, i. e., the valve having the byssal notch; exterior. DimensiouH: "Altitude" is distance between the base (Bi and the ain'X of the shell or umbo (U); "longitude" i.s the di.stance between the anterior extremity (A) ami the iOHtorior extremity (P); "diameter" is the maximum distance from the plane of the periphery (margin or border) to the top of the anhed di.k, when the .<hell in lying interior downward; A, anterior enjl; P. posterior end; B, bust; U, umbo; U P B A, disk; ae, anterior ear or auricle; ear auricle; 6m, bysstil notch or sinus; ba, byssal area; ps, posterior sinus; mn, .submargins or lateral areas; r, ribs; i>, interspaces.

high up, a little before the mesial line of the valves, and the pedal retractors are usually attached to the left valve above it, being often obsolete on the right .side. The ends of the resilium are received by subtriangular or oval pits in the

a The generic and subgenerie chuwification and descriptions, and also the general discussion relating to , are taken from Doctor Dall's momtgraph of the genus in "The Tertiary Fauna of Florida," Trans. Wagner Free Inst. Sci., vol. 3. pt. 4, 1898, pp. 689-758. In many cases parts of the discussion and descriptions have been copied verbatim. Unlen otherwise stated, all passages (K'currlng in quotations have copied from the above monograph.

4H

Tertiary And Quaternary Pecten8 Of California.

unibonal region. These pits may be shallow or deep; their basal margin sometimes projects slightly into the cavity of the valves; their apex is always nearh coincident with the umbonal point of the valve. In a few species in the right valve the lateiml margins of the pit are mised into tooth-like processes, which tit into corresponding depressions in the opposite valve (e. g., mrlftli Bernh.), but these are not liomologous with the so-called teeth of PlicaUdu and Spondylun, Outside of these, ludiating fanlike from the apex of the valve, are frequently found one to three pairs of more or less prominent laminse, which I call the cardinal crura, and farther away and below on the ridges which mark the lower boundary of the ears will sometimes be found another pair, only distally conspicuous, which I have named the auricular crura. The cardinal crura are most conspicuous in heav}" shells, especially such as Pecien proper and Lyntpevttfn and serve to adjust the closing of the valves, as does the hinge armature of the Teleodonts. In a few species the crura are

Flo. 2,— Same specieH as flg. 1. Right valve; A, B and ait in fig. 1; W, hinge line; rp, resillal pit: />p, provlnculum: c.c, cr, (>cardinal enira; hn, byn.Hal notch: nti, otenolinm; atf, Hdductr.>r Hear.

sufficiently prominent to actually intcrloi'k with the valves half open; in others hardly any trace of them is visible. Almost all species possess in the nepionic stage a well-marked provinculum, formed by an elongated area on each side of the pit, (covered by long, narrow, close-set taxodont teeth, separated by narrow grooved interspaces. In most the provinculum is evanescent or represented in the adult only by faint vertical strite, which cross the cardinal crura. In a few small, thin-shelled, mostly deep-watef species the provinculum is persistent and functional (e. g., P, tluiJcuiHtriftm Dall), forming an interlocking hinge. In Pevtt-n proper, Chlamyn and some other groups the upper cardinal margin of the right valve is bent over that of the left valve. There are occasional species in which the adult valves have each a flat area along the whole cardinal margin, covered by the ligament and forming a V-shaped groove between the upper margins of the valves, as in Hinfttl, The disk of the valve is usually rounded or oblique below and at the sides,

GENUS PECTEN Mf LLER. 47

})ut above continued on each side in a straight line to the umbo. The shell adjacent to these straight lines is frequently slightly different in sculpture from the rest of the disk, forming narrow areas, which were called by Conrad the 'submargins.' Above the submargins the auricles or ears project, usually differentiated by a linear depression ending in a sinus below. This sinus is sometimes absent in the posterior ears, as it is in the very young stages of the shell, but it is not an important systematic character, since the same species (e. g., P, latHinritm Conr.) may exhibit varieties some of which have a well-developed posterior swims while others are without it. The right anterior sinus is usually emphasized by a Hexuosity in the lower edge of the ear above it for the accommodation of the })yssus, and on the upper part of submargin are usually found a number of small, regularly spaced spines, which in life separate the threads of the })yssus and thus keep it from twisting with the motion of the water. The growth of the margin of the valve and ear does not always march with the development of these spines, so that a species which normally has them may exhibit stages when the valve margin has grown over the old set and the new set has not been formed, like the inequalities of growth shown by the margin of the aperture and the internal line of some This set of spines, resembling a short comb with curved teeth, has been called ctenolium, pectineum, and pectinidium. In old very heav} shells, which are held in place more by their own weight than by the formation of a byssas, they are often absent, but may usually be traced in the groove corresponding to the younger stages or fasciole of the sinus."'

The shell of Pecten, being thin in proportion to its surface, is in the adult usually ribbed or fluted. This condition is brought about, doubtless, by natural selection, and serves to strengthen the valves which, in swimming and falling to the bottom, are often subjected to rude shocks. Shelly matter is sometimes deposited internally in the shape of radiating lirie to still further strengthen the disk. In addition to the ribs and riblets, the surface of Pectin may be ornamented by line, almost microscopic groovings, which radiate from the umbo (shown in P. peckhami) or by a minute concentric sculpture due to imbricated incremental lines. A combination of minute concentric and radial sculpture often gives the surface, especially' in ChlamyH a checkered squamation or microscopic reticulation.

'"The original prototype of Pecten judging from the stages of recent shells and the succession of the fossils, was a thin, nearly smooth shell, with a taxodont provinculum and the posterior ears ill-detined.-' These characteristics have altered in the subsequent forms to meet conditions of environment, in some instances certain features appearing and then ))coming obsolete as their usefulness decreased.

*'The discrepancy in size of the valves appears to be more or less related to the activity of the animal; the species in which the difference is greatest being probably the more sedentary."

P, exccuvaim is an example of a species in which the discrepancy is very great, the right valve being extremely convex, while the left is somewhat concave. Where a discrepancy is shown the right is usually the more convex valve, although in some instances, notably in P. howern! and P. andUyiHoni the reverse is true.

The swimming habit is often exercised by Pecten it being more common to the thin-shelled, light, and young individual than to the thick-shelled, adult, and

50 Tkbtiary And Quaternary Peotens Ov California.

Subgenus PlagiocUnium Dall, 1898.

Tv'ix* drcnlarlH Sower by.

Ke.'ombliiig Equipevtcn but without radial striation; the concentric sculpture in looped lamella; the ribs strong, frequently smooth above; the subniargin impressed below the subequal auricles; the valves well inflated with a tendency to obli(|ue growth in the adult.

This group includes the following species of l\<ten: Audermn't andifrstmi var. htfrlirnnnifn orrosmKiH and its variety nif-ndenhdli circular Ix and its variety itquinlcafux. cooptrr! dlHCHs dtfHtril nrahenals pahloenslM jxiudcoHUitui*.

Subgenus Pseudamusium H. and A. Adams, 1858.

Tyix r;rotict/,i Chemnitz pMcudnnniHiuhi (Klein) Sowerby.

Shells small, thin, more or less translucent; inner face of the disk without lira*; sculpture discrepant on th( two valves, the right valve having the concentric and the left valve the radial (lements most pronounced; valves usuallv flattish or compressed.

The following Pectens are placed in this group: DHvidmnt UnnpicornHh feck- Inun! pedroamm ra/H/ofp/i/ ixud its f.Hhimoftl'enHlH and rancoureren*<ts,

Subgeiuis Anmsium Bolten, 1798.

Type phnrtPiHcttH Linne.

Valves flattish. internally Unite, externally usually smooth or faintly striated, both valves })eing similarly sculptured; the ctenolium absent and the byssal notch obsolete.

This group is representexl by the single species loiiipncen!i<.

Subgenus Propeamusium (iregorio, 1883.

Type P, /nef/tuf<>fffHT\\)er\ ft'nt'.sfratuy Forbes).

Right valve impressed about the distal margin, which is not fully calcified, partially concave, the sides partially (closed away from the, ears; the internal line present but shorter; the external sculpture chiefly concentric, while on the left valve, if present, it is radial; the recent forms usually glassy or pale colored in both valves.

In this group are included the* following Pectens: c/a/famt-Ns/ti infcrradiatua rlrerni and traijlnndt.

Subgenus Hinnits Defnmce, 1821.

Type //. corUzi

Shell (up to advanced youth) a typical Cldamtjs later becoming sessile and irregular, in which stage the resilial pit is elongated and cardinal margin develops an obscure

This group is represented by the single species ijujanUuH,

n

DESCRIPTIONS OF SUBdKNERA AND SPECIES. 51

KOf EXK PECTEXS.

[Those known first to in the Kocenc format ionn.]

PeCTEN (CllLAMYS) CALKINSI O. .sp.

ri. II, figs. 1 ami 2.

— Shell avomgin about 35 niillinietors in altitude, suhcircular, equivalve or nearly so, equilatenil, rather thin, somewhat ventricose, and with only serrate margins. Right valve with the (exterior surface ornamented by about 55 small, scjuarish, slightly imbricated ribs, which show a tendency to dichotomous near the end in some specimens; interspaces channeled and about one-half as wide as the ribs; hinge line about three-fifths the length of the disk; ears equal in length, flat and with the swell of the disk commencing at right angles to them; anterior (ar sculptured by 4 or 5 imbricated radiating ridges; byssal notch distinct; posterior ear sculptured in a similar manner to the anterior. Ift valve similar to the right except that in the former the ribs are slightly more rounded and the anterior ear has no notch.

Di//tefisa/?hs, —Wt. 30 mm.; long. 31 mm.; hinge* line 18 mm.; diameter tJ mm.

So far as known this species has no closely allied forms in any of the other California Tertiary formations, and for that reason is admimble as a diagnostic form for the Tejon. The type and several othei* specimens of this species were among some material collected by Dr. H. W. Fairbanks on the north side of the Sisar Valley, north of the Astirte oil wells, Ventura County. At this locality it was associated with the following characteristic Tejon fauna: Arr/i sp., (irflinm hreweri Mentriw lutrni MinUohix w//<////.v, sp., TnrrlteUn uiuixitmi Amerirnnlia planUionta Lam. var. horn!!.

The types of are now in the collection of the University of California. Xained in honor of Mr. Flink C. ('atkins, of the United States Geological Survey.

Eocene (Tejon). Sisar Valley, Ventura County (Fairbanks).

Pecten (Ciilamvs) landksi n. sp.

n. II, fi'H. 4, and o.

A'r/vyV/V>//.— Shell averaging about 34 millimeters in altitude, about as long as high, subcircular, equilateral, thin, slightly ventricose, and with Semite margins. Right valve more* ventricose than left, and flattening toward the in th( adult; surface ornaiiKMited by from 'Ih to 40 subequal, rounded,, more or less imbricate ribs, separated from each other by subequal, concave -bottomed interspaces, which avemge about as wide as the ribs; hinge line slightly longer than one-half length of disk; ears somewhat unecjual, the anterior being slightly the longer: antcM'ior car sculptured by 4 prominent radials, while the posterior has from to s |(\s.s prominent ones; byssal notch deep; whole surface of disk and (ars bv numerous flne im))ricatinir lamelhe. Ieft

52 Tertiary And Quaternary Pecten8 Of California.

valve more compressed than right, similarly sculptured, but with both ears slightly obliquely truncated, the anterior one showing a broad shallow not<*h. Hinge and mascle scars similar to P, hhindienA,

Dhrienmmft. — Alt. 34 mm.: long. 33.5 mm.; hinge line 19 mm.; diameter 12 mm. (right valve 7 mm., left valve 5 mm.).

The general outline and convexity of all the shells of this species appear to be a})out the same, but the ribs are quite variable, as regards both number and shape. In most cases the ribs are evenly rounded and equal in width to the interspaces, })ut in some cases they are ridgelike and narrower than the interspaces. In some specimens a few of the ribs become diehotomous distant 10 or 15 millimeters from the umbo, and small riblets are intercalated in a few of the interspaces at about the same distance. One specimen is contracted at a distance of about 30 millimeters, and shows sevenil intercalaries Iwyond the line of contraction. Some of the specimens of remind one somewhat of memhranotiuff Morton, from the Eocene of North Carolina, although the latter has more and narrower ribs, and is ornamented by liner imbricating sculpture than the former. landti is distinguishable from P, pronvn by its relatively longer disk and fewer but more prominent, regular, and less imbricated ribs. It is distinguishable from P, caikhil by its smaller size when adult, fewer but more elevated ribs, and relatively much shorter hinge line.

P. landi'si is found quite abundantly in a dark -greenish sandstone bed that outcrojw about KX) yards west of the junction of Stillwatr and Olequa creeks (U. S. Nat. Mus. locality 4019) one-fourth mile southwest of Little Falls, Lewis County, Wash. It is also found in a similar matrix in the bed of Olequa Creek (U. S. Nat. Mus. 4024), 1 mile north of the tirst locality. It is associated in this formation with a characteristic Eoi*ene fauna, among which are the following s[>ecies: planiemta Lamarck, Thracla dUlerl Dall, CraifateUittM sp., Meretru' sp., sp., Ptaria (cf.) lintuhi Conrad, Cardimn 2 sp., Barlnitia sp., Glycymeris sp., CorhuJa sp., CaUista sp., TinriteUa (cf.) uvamna Conrad, 4 sp., Ocinelyra sp., Ranella sp., CalyptrophoniJi sp., Lunatia sp., Turhlnella (0 Jp., Mnrex 2 s., Cohum sp., CasiM sp., Trttoniuin sp., Dentalinui (cf.) txHtper* ijhh and Naufihm sp. This horizon is prolmbly upper possibly above the Tejon. Named in honor of Prof. Henry Landes, Seattle, Wash.

(probably upper). Vicinity of Little Falls, Lewis County, Wash. U. S. Nat. Mus. locality 4019; 4024. (Arnold.)

(Chlamys) proa v us n. sp.

PI. II, tigs. iS, 7, and 8.

DffMoriptiOft. — Shell averaging 50 millimeters in altitude, much higher than long, compressed, subequivalve, and equilateral, except for the ears; base regularly rounded; margins smooth: sides straight and forming an acute angle at the umlx). Left valve with numerous more or less unequal, narrow, thread-like, imbricated ribs, between which are occasionally much finer intercalaries; interspaces about Jis wide as ribs, channeled and flat bottomed: whole surface of disk and

Eocene Pectens. 53

ears ornamented numerous, sliarp, imbricating lamella? of growth, which appear more prominently on the anterior portion of the disk; ear short, slightly obliquely truncated, and sculptund by numerous radials and imbricating lamellaB; anterior ear unknown, but much longer than posterior.

Dlmenslnn, — Alt. 88 mm.; long. 30 mm.: Tiinge line (restored and approximate) 18 mm.; diameter 7 mm.

This species is closely allied to tral-i Gabb, from the Oetaceous of the Pacific coast. It differs from the latter, however, in not having the diagonal microscropi<' sculpture so characteristic of that species.

A fragment of a much larger specinten thai the type of prrfOViiJ from the slime beds and probably the same species, shows, near the narrow ridge- like ribs separated by rather wide interspaces in each of which are two or three fine thread-like riblets. (PI. II, fig. s.)

The type of P. proarnt< which is now in the collection of the department of geology, Stanford University, is a poorly preserved cast of a left valve on which part of the original shell matter is still preserved. It came from beds of probable lower Eocene (Martinez) age in the ridge between the headwaters of Pescadero C'reek and San Lorenzo River, San Mateo County. At this locality it was associated with the following fauna: Terehratulina tejontrm-H Triton! am (cf.) caHfornlcvm, Patella (of.) traxki ILUrhm dlchotoina Ostrea (aff.) idriaemrU Turho sp.. Amiaa or Patella sp., Tertlraivhi n. sp., Cidariif (?) spines Sernele sp. After an examination of the above fauna Doctor Stanton was of the opinion that it was younger than the Chico (Cretaceous). It is certainly not typical Tejon (middle or upper ICocene), but appears to be closer to the Martinez fauna than to any other, and is, therefore, tentatively placed in the horizon of the latter.

Range.

Liower Eocene (Martinez 0- Between the headwaters of Pescadero Creek and the San Lorenzo River, San County (H. S. Gay; Arnold).

PeCTEN (pKOPEAMUSIUM) INTEKKADIATUS GaBB.

PI. II, figH. 9, 10, and 11. .

1869. Pecten interradiaiiis CJabb, Pal. Cal., vol. 2, 1S()9, pp. 199-200, pi. 38, fip?. 98, 98a. 1888. Pecleu hUerraduttiis Gabb, Coojxr, Seventh Ann. Cal. St. Min., 1887. p. 289. (From "Cretareuns B," which is Eoc*ene).

DeHrrlptiim. — Shell small, subcircular,equivalve, equilatei-al, compressed, thin; upper [left] valve, ears equal, moderately large; lower [right] valve, right ear long, deeply and narrowly emarginate. Surface marked by very numerous tine radiating lines, and obscure lines of growth. Internal surface of both valves bearing 8 ' straight, ecjuidistant, large ribs of variable length among themselves, extending from the beaks to near the middle of the shell and ending abruptly.''

DhnrnMiOfh'<, — Alt. 25 mm.; long. 24 nun.; hinge line 15mm.; diameter 2.5 mm.

This species may be disthiguished from P, fita?i/brdtjtif< by its larger size, narrower anterior ear of right valve, and fewer number of interior ribs. It is also distinguishable from P, r/atlfi//iefiJ<!.f< and icaylandi by its larger size and incon- 8pi<*uous (external surface sculpture.

54 Tertiary And Quaternary Pectens Of California.

Gahb states that the type of inffrradiatm is from the buff -colored shale east of New Idria, at or near the summit of the Tejou Ciroup'- [Eocene], where he found it very abundant. Two specimens from the colleirtion of the Tniversity of California, whicli were collected by Mr. H. W. Turner at New Idria, are in a hard, dark-colored shale.

A IWii'n allied to itifrrradiatu a<'Companied by the following note, was sent to the writer by Dr. J. C. Merriam, of Iferkeley: ''Road cutting Professor Richer's house at mouth of Strawberry Canyon, Berkeley. Cutting now walled up. A. C. L. Cretacreous shale.'' This species, which is represented by an internal cast, is 12 millimet4?rs in altitude, 10 millimeters in longitude, and has a hint* line /5.;) millimeters in length. It has io prominent rounded ribs extending from the umbo to the. and in several of the broad interspaces a rounded intercalary, which begins at a distance of about 7.5 from the umbo and extends nearly to the periphery. The anterior ear of the shell (which is a right valve) is slightly longer than the post(>rior, arcuate in , and has but a faint suggestion of a byssal notch.

The figures of inferred!atnt< which are natural size, are copied from the originals of the type in Pal. Cal., vol. 2, pi. 88, figs. 18, 9Sa.

Eocene (upper Tejon). New Idria, San Benito County ((jrabb; Turner).

OLKiOCKSE PECTESS.

[ThoM: knuwii tint to appear in the fDrmutionx.]

PI. TIT. fairs. 12aiMl i:;.

19()3. IWten (Peden) XrwoXiij >LS.

Drscrijff/oji. ShM averaging about 50 millimeters in altitude, slightly longcM* than high, plano-convex, etjuilateral, rather thin; base regularly rounded; sides only slightly concave above; margins smooth. Right valve (juite convex and ornamented with about 12 prominent, perpendicular-sided, slightly convex-topped ribs, separated by flat-bottomed, channeled interspaces about in width to the ribs; surface sculptured by small, almost imperceptible, obsolete, radiating striations and numerous fine sharp concentric lines; hinge line considerably longer than one half length of disk; ears subequal; anterior with shallow ])yssal notch and fine, sharp concentric lines; posterior similarly sculptured, but rectangularly trunaited. .Left valve flat, with slight conctivity near umbo; lateral areas rather prominent; ribs squarish, with slightly <'convex tops narrower than those of the right valve and with proportionally wider interfaces; ears su})equal, rectangularly truncated, and with surface scul])tured by numerous fine, sharp incremental lines.

iJiHuiisJfniH, — Alt. 52 mm.; long. 55 mm.; hinge line 82 mm.; diameter about 18 mm.; unbonal angle 110 .

This sjxcies is allied to and may be its pi-ecursoi*, as it is very similar to the latter in most respects. P. sunrfierrttzcnsis may be distinguished

Oligocene Pectens. 55

from hell by its fewer ribs (11 instead of 14) and relatively smaller size when adult.

saiU'tiecruzcnHiH is so far known only from beds which appear to be transitional from the Oligocene to the Miocene. At locality No. S. J. U. Geol. Survey) on Twobar Creek, one-fourth mile above its junction with San Lorenzo River, Santa Cruz County, the was found associated in a soft sandstone with the following species: IWtm hiuuitier! n. sp., Cyftnra (rf,) vespertina Tntomwn sp. No. 1, ((i (?) sp., VoUUd (rf,) Xtunihi n. sp. (large, with coarse sculpture), Lf?dff ay), B. and C, Cularixii) spines, Odl/f' sp. Tel/hui {Angtilus) sp., Otnfitfffi n. sp., near (nntpen Teredo sp., Cluone (vf,) rnatlnnnmn!. One mile southeast of Cowell's asphaltum quarry (locality 30), near Santa Cruz, P. sanctiiefriizensh is associated with perhhawf. Xuctila sp., Phacfttdes sp., and Cldone sp.

The type, a beautifully preserved mold of a left valve, is now in the coUecrtion of the department of geology, Stanford University. A small co])blestone containing two right and two left valves of P, Mnctivcruzinntn was found by Miss L. J. F. Hecox, of Santa Cruz, as float iri Bear Creek, about 2 miles from the type locality. One of these right valves is figured and serves as a cotype.

Oligocene-Miocene. Twobar Creek and Bear Creek, Santa Cruz County (Arnold; Hecox).

Pkcten (Chlamys) branneri n. sp.

PL III, fiB. y, 10, and 11.

DeHcr!pf!on, — Adult shell averaging about 80 millimeters in altitude, higher than long, ecjuivalve, slightly convex, and eiiuilateral, except for ears; sides only slightly concave above; base regularly rounded below. Right valve with from !i() to 22 prominent, narrow, more or less scaly or spiny ribs, which in the adults are sometimes medially sulcated or dichotomous; interspaces genemlly much broader than the ribs, channelled and usually containing a spiny or scaly intercalary I'ib; whole surface sculptured by imbricating incremental lines, often also by microscopic reticulations; hinge line about two-thirds length of disk; anterior ear much produced and sculptured by 6 to lo imbricated ridges, which are by equally wide reticulated interspaces; byssal notch profound; posterior ear thre(*-fifths length of anterior, and sculptured similarly. Left valve similar to right.

-nalfPtiH, Alt. 65 nmi. ; long. mm.; hinge line 4o nun.; diameter 14 nun.; umbonal angle JSS .

This species varies considerably in the degree of importance of the minor sculpture, such as reticulation, and size of the sulcations and intercalaries. Although allied to the Chltmtjfi group, it has larger posterior ears than other species of the group that have come under the writer's notice. lyrannrrl resembles P. in size, outline, and general sculpture, but is distinguishable by having only about one-half jus man}' ribs and nuich larger posterior ears.

56 Tkrtiary And Quaternary Pecten8 Of California.

So far as is known, P, hratinerl is confined to the lowest horizon of the Miocene and top of the Oligocene. It is very abundant at the type locality, Tuff Hill, near Stanford University. One large right valve was also obtained from the fine sandstone immediately overlying the San shale series (Oligocene) in Twobar Creek, near the town of Boulder Creek, Santa Cruz County.

The type, like all of the known specimens of the species, is a mold, and is now in the collection of the department of geology, Iceland Stanford Junior University. Named in honor of Dr. J. C. Branner, professor of geology in that institution.

Range.

Miocene (lower). Tuff Hill, Stanford University, Santa Clara County (Branner;

J. P. Smith: Arnold). Oligocene (upper) or Miocene (lower). Twolmr Creek, near Boulder Creek, Santa

Cruz County (Newson; Arnold).

Pecten (Psei'dami'Sium) I'ECKHAMi Gabb.

PI. Ill, ligH. 6, 7, and 8.

1869. Perten peckhami Gabb, Pal. Cal., vol. 2, 1869, pp. 59, 00, pi. 16, figs. 19 and 19a. 1888. Pecten peckhami , Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 258. 1898. Pecten peckhami Gabb, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 705.

DeHoriptlon. — Shell averaging about 20 millimeterH in altitude, subcircular, subequivalve, slightly inequilateral, thin, usually compressed, and with smooth margins. Right valve with the disk showing several small, more or less obsolete, irregular concentric undulations, numerous fine incremental lines' and numerous fine obsolete radiating lines; hinge line about two-thirds of the longitude of the disk; anterior ear produced, separated from the body of the shell by a marked groove and a deep, narrow sinus, and prominently sculptured by 6 or 7 radiating ridges and numerous concentric elevated incremental lines; posterior ear not separated by any distinct line from the disk surface and ornamented only by concentric lines and obsolete undulations. Left valve similar to right except that the anterior ear is flat, the swell of the shell commencing with nearly a right angle with the ear surface: surface of anterior ear usually sculptured only by incremental lines, but occasionally with radiating stria? also.

Dimemiofis, — Alt. 21 mm.; long. 21 mm.; hinge line 14 mm.; diameter 2 mm.

As a rule only the molds or casts of this species are found in the shales in which they occur, and for this reason some of the characteristics of sculpture of the species are generally lacking. For example, in a large series of specimens examined, only two or three of the shells showed the radiating sculpture. The disks are generally obliquely distorted and often compressed, but the sculpture on the anterior er of the right valve is almost always present and is chamcteristic.

In ('alifornia this species is found from the San Lorenzo formation (Oligocene) to the Monterey or middle Miocene. pH-khami is found abundantly in the shale in Newell Oeek canyon, 2 miles above Ben Lomond, Santa Cruz County, where it is asscx'iated with Area montereyana Osniont, Corhala sp., Cyth-

Oligocene Pecten8. 57

erea sp., Diplodontan. sp., Venicardla (?) n. sp., Leda 2 n. sp., Phacoides sp., Semele n. sp., and TelUna cf. cmiesta Conrad.

P. peckhami is also abundant in certain horizons of the Oligocene-Miocene of Washington, and Mr. Diller has found it in some shales in Oregon. It occurs nar the base of the Oligocene-Miocene section between Bean and Restoration points, west of Seattle, King County, Wash., associated with Clypeaster (?) sp., Terehratula sp., and Teredo sp. At Freshwater Bay, Clallam County, Wash., it is found with Dolixtm petrosum Conrad, Junm sp., Nntica or Lunntia sp., Nueula cf. declsa Conr., Volutilithes n. sp., Dentalium suhHtriatum Conrad, Phacoidea acHtUineatim Conrad, Solemya sp., Leda sp., and MarginAlu or Erato sp. Farther west along the Strait of Juan de Fuca, miles east of Gettysburg, Clallam County, Wash., P, peckhami associated with Nticxda sp., Leda n. sp., Dentalium milstriatum Conrad, JVatica sp., etc. One of the specimens of peckhami from near Bean Point, Washington, shows the anterior ear of the left valve to be ornamented by about 13 fine elevated radiating lines. Owing to the comparatively good state of preservation of the Washington specimens, nearly all of them show the minute concentric and radiating sculpture of the disk and ears in addition to the characteristic undulations of the former.

Miocene (middle). San Pablo, Contra Costa County (Gabb); southeast of Pinole, Contra Costa County (Lawson); Langley Hill, Alpine district, and south of Portola, San Mateo County; Felton and Ben Lomond, Santa Cruz County (Smith, Newsom, Arnold); Carmelo Valley, xVIonterey County (Lawson, Turner); Templeton, San Luis Obispo County (Fairbanks, F. M. Anderson); northwest of Tulare Lake, Tulare County (Watts); Ojai ranch, Ventura County (type locality) (S. F. Peckham); Big Panoche Creek, Fresno County (Turner); 4 miles south of McKittrick, Kern County (Eldridge).

Oligocene-Miocene. Ridge west of the headwaters of Boulder Creek and western slope of the south end of Ben Lomond Mountain, Santa Cruz County (Newsom, Arnold). In Washington at localities 4112a and 4118, between Bean and Restoration points. King County; locality 4121, Freshwater Bay; location 4120, 2 miles west of Port Crescent; locality 4114, H miles east of Gettysburg, Clallam County (Arnold).

Pectkn (Propeamusium) (lallamensis n. sp.

PI. Ill, figs. I, 2, 3, and

Pesc7'iptian, — Adult shell averaging about lo millimeters in altitude, subcircular, equivalve, thin, compressed, and with smooth margins. Right valve ornamented externally by numerous equally elevated, sharp, iflightly imbricate, concentric lamella?, separated by equal interspaces, each of which is about five times as wide as the thickness of a lamella; hinge line somewhat longer than one-half length of disk; ears decidedly unequal, the anterior being about twice as long as the posterior; anterior ear arcuate in front and sculptured by numerous regular, sharp, elevated, concentric lamellae and 5 or (3 slightly unequally spaced radials;

58 Tertiary And Quaternary Pectens Of California.

byssal notch not profound; posterior oar rectangularly truncated and ornamented with concentric sculpture similar to that of the anterior; interior of disk strengthened by nine strong, rounded, elevated, mdiating ribs, which terminate abruptly at a length of or 7 millimeters; the middle ribs are straight, but occasionally the lateml ones are faintly arcuate toward the middle rib. Ijeft valve beautifully ornamented externally by numerous regular, thin, concentric, imbricating, prominently elevated lamelhe which, sloping at an angle of about 45" toward the umbo, rise into 10 or 11 prominent, rounded, radiating pseudo-ribs, separated somewhat wider interspac*es, in nearly every one of which is an intercalated, imbricated pseudo-riblet; this riblet begins only after the shell attained a height of about 1.5 to 2 millimeter*s; ears similarly sculptured to those of the right valve.

I)!iH&ni<!o7ii<, — Alt. (type, left valve) 10 mm.; long. 9.5 mm.; hinge line 5.5 mm.; diameter 0.75 mm.

This beautiful little Pecien appears to be allied to J?. itmifordctiHin but is easily distinguished from the latter by its beautifully lamellated surface, and in possessing 9 instead of 10 or more internal riblets.

The type of claUainemsis is a left valve (U. S. N. M. No. 164922) and was found at locality 4100, li miles east of Pillar Point, near the mouth of the Pysht River, Clallam County, Wash., where it was associated with Aturla cf. zlczav Sowerb\-, Dolium petrrmim Conrad, Fuifua sp., Natica or Lunatin Marglnella or Erat sp., Niioula sp., Leda sp. (large, smooth), Tellhia {Aiujulxm) sp., SoUmya sp., Deiitalmm Huhsfrlafum Conrad. The cotype is a right valve (U. S. N. M. No. 164928), is from locality 4070, Bean Point, King County, Wash., and is associated there with Terehratula sp., Tuf*rltelUt sp., Marglnella. or Erato sp., Natica or Lunat/a sp, Glycymeriif sp., and Antyn sp.

Both of the Icxalities at which cMlavtentdx have so far been found are in the lower portion of the Oligocene-Miocene series.

Oligocene-Miocene. Mouth of Pysht River, Clallam County, and Bean Point, west of Seattle, King County, Wash. (Arnold).

(Proieamusium) waylandi n. sp.

PI. Ill, ligs. 4 and 5.

Descript!o7i, — Adult shell averaging about 9.5 millimeters in altitude, somewhat longer than high, subcircular, ecjuivalve, equilateral, thin, somewhat convex in youth, but becoming more compressed with age; margins smooth. Disk of right valve sculptured by numerous tine lines of growth and numerous, more or less obsolete, tine radiating lines; hinge line equal to about one-half the length of the disk; ears anterior arcuate in front and faintly sculptured concentrically by sharp lines and radially by faint ridges; byssal notch narrow and shallow; posterior ear slightly obliquely truncated and sculptuied by faint i*dial ridges and fine, sharp, concentric lines; interior of disk strengthened by 8 subequal, strong, narrow, smooth, convex-topped riblets, which are widely separated and which terminate abruptly at about 6 to 8 millimeters from the umbo; these

Miocene Peotens. 59

internal riblets are usually straight, but the ones distant from the center are often slightly arcuate toward the center. Left valve, up to an altitude of 6 or 8 millimeters, ornamented })v 8 more or less prominently elevated, narrow, convex- topped radiating ridges, corresponding with the same num})er of equally long, smooth, convex-topped internal riblets; whole surface of disk sculptured by numerous subequal, inequidistant, sharp, radiating lines (usually varying from 5 to 7 between each major ridge) and faint incremental lines, the latter becoming prominent as the radiating ridges become obsolete; ears similar to those of right valve, with the exception that there is no bys.sal notch in the anterior one.

DlinemaioiuH. — Alt. *J.5 mm.; long. 12 mm.; hinge line 5.5 mm.; diameter about 0.75 mm.

This little Pecten is closely allied to but may be distinguished from the latter by the more prominently elevated ridges on the left valve, the greater prominence of its microscopic radial sculpture, and the smaller number (8 instead of 10 to 12) of internal riblets. v:(Ujlandi is distinguishable from vlallmmnHis with which it is associated, by its relatively longer disk, simple and less prominent external sculpture, and fewer (8 instead of *J) internal riblets. It is allied to P. hitnradlatm (iabb, but is much smaller, being only about one-half as large, has a miich shorter* hinge line, and its left valve is much more strongly sculptured; it also occurs in a horizon later than that in which P. interradiatiis is found.

The type of P. trayhmd! (U.S.N.M., No. 104924) was found with the type of P. clalJiimeimH at locality 4100, miles east of Pillar Point, near the mouth of the Pysht River, Clallam County, Wash., and a list of its associated species is given in the discussion under P. dallainensls. The cotype of P, icayhmd! (U.S.N.M., No. a mold of the interior of a right valve, was found at locality 4115, 2i miles west of Gettysburg, Clallam County, Wash., where it was associated with F((8UHs\)., Leda sp., Macotna or TtHhui sp., and Aturia cf. ziczar Sowerby. The faunas associated with P, vxiylandl, at both of the localities where it has so far been found, indicate the lower portion of the widely distributed Oligocene-Miocene series.

The species is named in honor of Mr. Kussell G. Wayland, of Seattle, Wash., who assisted the writer during part of his paleontological reconnaissance trip along the northwestern coast of Washinirtou in the summer of 1904.

Oligocene-Miocene, 2.V miles west of Gettysburg, and Vh miles east of Pillar Point, near the mouth of the Pysht River, Clallam County, Wash. (Arnold)

Miocese Pkctess.

[Thane known first to in the Micxent* formations.]

Pectkx cahrizoensis n. sp.

PI. IV, W. 1, la, 11), 2, 8, and 8a. 1898. Pecten sp. indet., Dall, Tnuis. Wagner Free Inst. S<'i., vol. 8, pt. 4, p. 706, line 13.

DeHcplptton, — Shell averaging about 42 millimeters in altitude, longer than high, inequivalve, plano-convex, equilateral, and with smooth margins; base evenly rounded; sides concave above. Right valve convex, ornamented by about 18 or

58 Tertiary And Quaternary Pectens Of Calibornia.

byssal notch not profound; posterior ear rectangularly truncated and ornamented with concentric sculpture similar to that of the anterior; interior of disk strengthened by nine strong, rounded, elevated, radiating ribs, which terminate abruptly at a length of or 7 millimeters; the middle ribs are straight, but occasionally the lateral ones are faintly arcuate toward the middle rib. Left valve beautifully ornamented externally by numerous regular, thin, concentric, imbricating, prominently elevated lamelhe which, sloping at an angle of about toward the umbo, rise into 10 or 11 prominent, rounded, radiating pseudo-ribs, separated b}' somewhat wider interspaces, in nearly every one of which is an intercalatexl, imbricated pseudo-riblet; this riblet begins only after the shell has attained a height of about 1.5 to 2 millimeters; ears similarly sculptured to those of the right valve.

Dltne)}i<!o7hs, — Alt. (type, left valve) 10 mm.; long. 9.5 mm.; hinge line 5.5 mm.; diameter about 0.75 mm.

This beautiful little Pecten appears to be allied to P. but is easily distinguished from the latter by its beautifully lamellated surface, and in possessing 9 instead of 10 or more internal riblets.

The type of claUunumHis is a left valve (U. S. N. M. No. 164922) and was found at localit\' 4100, li miles east of Pillar Point, near the mouth of the Pysht River, Clallam County, Wash., where it was associated with Aturia cf. zlczac Sowerby, Dolium petroifum Conrad, Fuus sp., Nat tea or Lunatia Margmella or Evato sp., Nuoidxi sp., Leda sp. (large, smooth), TelUna {Aiigulus) sp., Solmya sp., Dentalium HHlmirhtum Conrad. The cotype is a right valve (U. S. N. M. No. 164923), is from locality 4070, Bean Point, King County, Wash., and is associated there with Teiebratula sp., Tinrltella sp., Marglnella or Erato sp., Natica or Limatiafip, Glycymeria sp., and Antyns sp.

Both of the localities at which P. dallarnen have so far been found are in the lower portion of the Oligocene-Miocene series.

Oligocene-Miocene. Mouth of Pysht River, Clallam County, and Ifean Point, west of Seattle, King County, Wash. (Arnold).

Pkcten (Prophamustum) waylandi n. sp.

PI. Ill, ligs. 4 and 5.

Desci'ipthn, — Adult shell averaging about 9.5 in altitude, somewhat longer than high, sulmircular, Cijuivalve, equilateral, thin, somewhat convex in youth, but becoming more compressed with age; margins smooth. Disk of right valve sculptured numerous fine lines of growth and numerous, more or less obsolete, tine radiating lines; hinge line equal to about one-half the length of the disk; ears subequal; anterior arcuate in front and faintly sculptured concentrically by sharp lines and radially by faint ridges; b3'ssal notch narrow and shallow; posterior ear slightly obliquely truncated and sculptured by faint radial ridges and tine, sharp, concentric lines; interior of disk strengthened by 8 subequal, strong, narrow, smooth, convex-topped riblets, which are widely separated and which terminate abruptly at about 6 to 8 millimeters from the umbo; these

Miocene Peotens. 59

internal riblets aro usually straight, but the ones distjint from the center are often slightly arcuaU toward the center. Left valve, up to an altitude of 6 or 8 millimeters, ornamented by 8 more or less prominently elevated, narrow, con vex- topped radiating ridges, corresponding with the same number of equally long, smooth, convex-topped internal riblets; whole surface of disk sculptured by numerous 8ube((ual, inequidistant, sharp, radiating lines (usually varying from 5 to 7 between each major ridge) and faint incremental lines, the latter becoming prominent as the radiating ridges become obsolete; ears similar to those of right valve, with the exception that there is no byssal notch in the anterior one.

Dinumalons, — Alt. 9.5 mm.; long. 12 mm.; hinge line 5.5 mm.; diameter about 0.75 mm.

This little Pectrn is closely allied to but may be distinguished from the latter by the more prominently elevated ridges on the left valve, the greater prominence of its microscopic radial sculpture, and the smaller number (8 instead of 10 to 12) of internal riblets. mnjUmdl is distinguishable from vJalhtmi'taxis with which it is associated, by its relatively longer disk, simple and less prominent external sculpture, and fewer (8 instead of i) internal riblets. It is allied to P, hiUvradiatuH (iabb, but is smaller, being only about one-half as large, has a miich shorter* hinge line, and its left valve is much more strongly sculptured; it also occurs in a horizon probabh later than that in which /'. interradtdtns is found.

The type of P. irayhmdl (U.S.N.M., No. 104924) was found with the type of P. daJhniumsU at locality 4lo0, miles east of Pillar Point, near the mouth of the Pysht River, Clallam County, Wash., and a list of its associated species is given in the discussion under P. vbdlamenHiA. The cotype of P, waylojidl (U.S.N.M., No. a mold of the interior of a right valve, was found at locality 4115, 2i miles west of Gettysburg, Clallam County, Wash., where it was jissociated with FuHHx sp.. sp.. Ma anna or Tdlina sp., and Atur!a cf. ziczav Sowerby. The faunas associated with P, traylandl, at both of the localities where it has so far found, indicate the lower portion of the widely distributed Oligocene-Miocene series.

The species is named in honor of Mr. Kussell (1. Wayland, of Seattle, Wash., who assisted writer during part of his paleontological reconnaisstmce trip along the northwestern coast of Washington in the sunnuer of 1904.

Oligocene-Miocene, 2.V miles west of Gettysburg, and 11 miles east of Pillar Point, near the mouth of the Pysht River, Clallam County, Wash. (Arnold)

MIOi ESE I' FA TIJXS.

[Tin we known first to appcur in tin* Micx-eno fonnations.]

Pecten cakrizoknsis n. sp.

PI. IV, lip.. 1. la, lb, 2, 8, and 3. 1898. Pecteu sp. indet., Dall, Trans. WaMHier Fm- Inst. Sci., vol. 3, pt. 4, p. 706, line 13.

Description, — Shell averaging about 42 millimeters in altitude, longer than high, ine([uivalve, plano-convex, equilateral, and with smooth margins; base evenly rounded; sides concave above. Right valve convex, ornamented by about 18 or

58 Tkrtiary And Quaternary Pectens Of California.

byssal notch not profound; posterior ear rectangularly truncated and ornanienUd with concentric sculpture similar to that of the anterior; interior of disk strengthened by nine strong, rounded, elevated, radiating ribs, which terminate abruptly at a length of 6 or 7 millimeters; the middle ribs are straight, but occasionally the lateml ones are faintly' arcuate toward the middle rib. left valve beautifully ornamented externally by numerous regular, thin, concentric, imbricating, prominently elevated lamelhe which, sloping at an angle of about 46' toward the umbo, rise into 10 or 11 prominent, rounded, radiating pseudo-ribs, separated by somewhat wider interspaces, in nearly every one of which is an intercalated, imbricated pseudo-riblet; this riblet begins only after the shell has attained a height of about 1.5 to 2 millimeters; ears similarly sculptiu'ed to those of the right valve.

Dimensions, — Alt. (type, left valve) 10 mm.; long. 9.5 mm.; hinge line 5.5 mm.; diameter about 0.75 mm.

Tliis beautiful little Peciei\ appears to be allied to P, ataiifcfrdrnsiM but is easily distinguished from the latter by its beautifully lamellated surface, and in possessing 9 instead of 10 or more internal riblets.

The type of is a left valve (U. S. N. M. No. 164922) and was found at locality 4100, li miles east of Pillar Point, near the mouth of the Pysht River, Clallam County, Wash., where it was associated with Aturla cf. zlczae Sowerby, Dolium petroHuin sp., Natica or Lunatia Marglnelh' or Erato sp.. Nucule sp., Leda sp. (large, smooth). Tell hut (Angidns) sp., Solmya sp., Dentalixim Hulmtrlaiinu Conrad. The cotype is a right valve (U. S. N. M. No. 164923), is from locjility 4070, Bean Point, King County, Wash., and is associated there with Terrhratula sp., Tn7Tltella sp., Marglnella or Erato sp., Natica or Lunatla sp., GlycymerlH sp., and Astyrls sp.

Both of the localities at which clallamenKU have so far been found are in the lower portion of the Oligocene-Miocene series.

Ranok.

%

Oligocene-Miocene. Mouth of Pysht River, Clallam County, and Bean Point, west of Seattle, King County, Wash. (Arnold).

PEcrTKN (Propeamusium) waylandi n. sp.

PI. Ill, ligH. A anl 5.

Description. — Adult shell averaging about 9.5 millimeters in altitude, somewhat longer than high, subcircular, valve, thin, somewhat convex in youth, but becoming more compressed with age; margins smooth. Disk of right valve sculptured by numerous fine lines of growth and numerous, more or less obsolete, fine radiating lines; hinge line ecjual to about one-half the length of the disk; ears anterior arcuate in front and faintly sculptured concentrically by sharp lines and radial' by faint ridges; })vssal notch narrow and shallow; posterior ear slightly obliquely truncated and sculptured by faint radial ridges and fine, sharp, concentric lines; interior of disk strengthened by 8 subequal, strong, narrow, smooth, convex-topped riblets, which are widely separated and which terminate abruptly at about 6 to 8 millimeters from the umbo; these

Miocene Pectens. 59

internal riblets are usually' straight, hut the ones distant from the center are often slight!}' arcuate toward the center. Left valve, up to an altitude of 6 or 8 millimeters, ornamented })v 8 more or less prominently elevated, narrow, convex- topped radiating ridges, corresponding with the same number of equally long, snjooth, convex-topped internal riblets; whole surface of disk sculptured by numerous subequal, inequidistant, sharp, radiating lines (usually varying from 5 to 7 each major ridge) and faint incremental lines, the latter becoming prominent as the I'radiating ridges becojne ears similar to those of right valve, with the exception that there is no byssal notch in the anterior one.

Dutunnlons, — Alt. 9.6 mm.; long. 12 mm.; hinge line 5.5 mm.; diameter about 0.75 mm.

This little Pecteii is closely allied to MtanftrdenHU but ma}' be distinguished from the latter by the more prominently elevated ridges on the left valve, the greater prominence of its microscopic radial sculpture, and the smaller number (8 instead of 10 to 12) of internal riblets. P, icaijJaudi is distinguishable from P, vlalhinu'iiHtH with which it is associated, by its relatively longer disk, simple and less prominent sculpture, and fewer (8 instead of 9) internal riblets. It is allied to P, hitrrradiatus Gabb, but is much smaller, being onh' about one-half as large, has a miich shorter* hinge line, and its left valve is much more strongly sculptured; it also occurs in a horizon probably later than that in which P. inter rmluduB is found.

The type of P. mayhmdl (U.S.N.M., No. I()4y24) was found with the type of P, vlalhiinensbi at locality miles east of Pillar Point, near the mouth of the Pysht River, C'lallam County, A\'ash., and a list of its associated species is given in the discussion under P, clalUunens!, The cotype of P, traylamll (IT.S.N.M., No. 1<)4925), a mold of the interior of a right valve, was found at localit}- 4115, 2i miles west of Gettysburg, Clallam County, Wash., where it was associated with FuHHs sp., Lfda sp., Mncotna or TdHna sp., and Atvria cf. zlczav Sowerby. The faunas associated with at both of the localities where it has so far found, indicate the lower portion of the widely distributed Oligo(*ene-Miocene series.

The species is named in honor of Mr. Kussell G. Wayland, of Seattle, Wash., who assisted the writer during part of his paleontological reconnaissance trip along the northwestern coast of Washington in the sunnner of 1904.

Range.

Oligocene-Miocene, '1\ miles west of Gettysburg, and mil(\s east of Pillar Point, near the mouth of the Pysht River, Clallam County, Wash. (Arnold)

[Thoso known first to appear in the Mirx-ene formation.]

Pectkn ('ahrizoensis n. sp.

PI. IV, figs. 1, la, 11), 2, 3, and 3a. 1898. Pecieii sp. Dall, Trans. Wagiu'r Free Inst. Sci., vol. 3, pt. 4, p. 706, line 13.

Dernptlon, — Shell avcmging- about 42 millimeters in altitude, longer than high, inequivalve, plano-convex, e((bilateral, and with smooth niargins; base evenly rounded; sides concave above. Right valve convex, ornamented by about 18 or

60 Tertiaby And Quaternary Pectens Of Calibornia.

19 prominent, square, flat-topped, medially sulfated ribs; interspaces channeled and slightly narrower than ribs; whole surface sculptured by tine, regular, concentric incremental lines; hinge line less than one-half length of disk; ears subequal, convex, and ornamented by concentric linens. Left valve flat or slightly concave, ornamented by about 17 prominent, equal, equidistant, narrow, convex-topped ribs, which are sepamted by flat-bottomed interspaces nuuh wider than the ribs; surface sculptured by numerous tine, regular, wavy, concentric lines; ears concave and sculptured bv concentric lines.

Dimensum., — Alt. 36 mm.; long. mm.; hinge line 15 mm.; diameter 8 mm.; umbonal angle (left valve) 105.

This species belongs to the group of which P. diegmU is the living member. P. carrizoenls P. Htearnsii,, and P, diegensltt taken in chronologic order as above ma}- represent a genetic series. The three species are alike in most respects: They are all plano-convex, have squarish, more or less sulcated or longitudinally ridged ribs, convex ears on the right valve, and rather narrow, rounded ribs and concave ears on the left.

P. caiTizoeuHw differs from the other two mem])ers of the group in the smaller number and less prominence of its ribs and in its relatively much shallower and narrower interspaces.

The Pecten mentioned by Dall on page 706 of the Transactions of the Wagner Free Institute as coming from the Miocene deposits near San Diego was compared with the type of P. carnztfensln and found to be of this species.

The type locality of P, carrvzfjenw is at the head of Garnet Canyon, about 12 miles north of the Mexican boundary, in the Carrizo Creek district, San Diego County. The beds in this district contain a fauna different from any of the other known California formations, but from other considerations it is deemed almost certain that the deposits are of Miocene age. Just what horizon the beds represent has not yet been determined. (See list of Carrizo Creek district fossils in Pail I, p. 22, and list of Santa Rosalia, Lower California, fossils under P, cerrosensis var. niendenhidli p. 85.)

The type of carrizoenHUy which was collected Dr. Stephen Bowers, is now in the collection of Delos Arnold.

Miocene. Head of Garnet Canyon, 12 mile north of Mexican boundary, San Diego County (Bowers); Santa Rosalia, Lower California, west of and across the Gulf from Guaymas, Mexico (G. P. Merrill; E. Palmer).

Pecten (Pecten) keep n. sp.

PI. V, fig. 1; PI. VI, figs. 1 and 1.

Description, — Shell averaging about 75 millimeters in altitude, longer than high, plano-convex, equilatei'al, and with smooth margins; sides concave above; lateral area very broad. Right valve ventricose and ornamented ])v about 20 low, broad, rounded ribs, separated by shallow interspaces in which are low, broad intercalaries; the sulcation on the interior of the valve corresponding to the

Miocene Pectens. 61

intercalary is often quite prominent; whole surface sculptured by inconspicuous incremental lines; hinge line more than one-half length of disk; ears equal, somewhat convex, rather obliquely truncated and turned up slight' at the corners; sculpture of ears consists of line incremental lines; byssal notch rather small. Left valve flat, with a slight tendency toward concavity- near the umbo, with broad lateral areas and with 18 or 19 low, mther flat-topped ribs; interspaces somewhat wider than the ribs; surface sculptured by fine incremental lines; eai-s concave, obliquely truncated and sculptured })y more or less irregular concentric lines.

Di/nenslom, — Alt. 75 mm.; hinge line to ventral margin 72 nun.; long. 82 mm.; hinge line 35 mm.; diameter 20 mm.; umbonal angle (left valve) 102.

This species is distinguishable from vinjde.nl and P, exvwvatuH which it resembles in general characteristics by its greater relative length, somewhat less convexity, greater umbonal angle, broader lateml arenas and lower ribs.

This species is foiuid associated with P. oamzih-nKls and (Mreit vespertma in beds in the Carrizo Creek district which are probably of Miocene age. The type is from Alverson Canyon, San Diego County, and is now in the collection of Delos Arnold. Named in honor of Prof . Josiah Keep, of Mills College, whose works on California conchology have greatly stimulated the study of that subject on the Pacific coast.

Miocene. Eight miles north of Mexican in Alverson Canyon, Carrizo Creek district, San Diego County (Bowers); Santa Rosalia, Lower California, west of and directly across the (xulf from (fuaymas, Mexico (E. Palmer).

Pecten (Patinopecten) coosensis Shumard.

PI. VI, fig. 2; PL VII, ligs. 2 and 2a.

1868. Pecten cooAensis Shumard. Trans. St. IjOHW Acad. Std., vol. 1, pt. 2, 1858, p. 122.

1864. Pecten coosfieTusis Shumard, Meek (typ. err.), Miocene che<'k list, Smithsonian Miscall. 1864, p. 3 ifide Dall, 1898).

1869. Pecten coosensis Shumard, Gabb, Pal. Cal., vol. 2, 1869, p. 122.

1898. Pecten Ptituiopecten) coosenxim Shumard, Dall, Trans. Wagner Free Inst. Soi., vol. 3, pt. 4, 1898, p. 700, pi. 26, fig. 2.

Description, — Shell averaging about 110 millimeters in altitude, slightly longer than high, valves both well compressed, equilateral, and with margins smooth; sides only slightly concave, and sloping at only a moderately low angle. Right valve with 21 to 31 prominent T-rail shaped ribs, flattened and sometimes faintly dichotomous above, overhanging narrow, deep, almost flat-bottomed channels; whole surface sculptured with more or less prominent tine concentric lines; hinge line nearly equal to one-half length of disk; anterior ear slightly produced and sculptured by radiating ridges and imbricating concentric lines; byssal notch wide and deep; posterior ear rectangularly truncated, and sculptured by sharp incremental lines and sometimes by obsolete radial ridges. Left valve with narrower, rounded, concavesided ribs and wider, round-bottomed interspaces; sculpture of numerous, sharp,

62 Tebtiary And Quaternary Pectkn8 Of California.

raised, concentric lines; ears siibequal, and havinjif incremental and sometimes obsolete I'dial sculpture.

DhnetiHlonti, — Alt. 110 mm.; long. 115 mm.; hinge line 54 mm.; diameter

This fine species is distinguishable by the great number and shape of its I'ibs. Specimens found at Howe's place, northeast of Corvallis, benton County, Oreg., have onh' from 25 to 27 ribs on the right valve. Otherwise the specimens are similar to the typical form.

Found alnmdantly in the Enipire beds at Coos Bay, Oregon, whence the type came.

Miocene. Coos Bay, Oregon (Shumard; Dall; A. W. Crawford and others); Howe's place, northeast of Corvallis, County, Oreg. (Diller).

Pectex (Patinopkcten) dillkri Dall.

PI. V, fir. 2.

1901. Pecien {Lyropeden) dilhri Dall, Nautilus, vol. IH, no. 10, Feb., 1901, p. 117.

The original description is as follows:

Ih'Hcnpfion. — Shell large, averaging about 190 millimeters in altitude, rather compressed, nearly orbicular with a relatively short, straight, hinge line, doisally rectangular, nearly smooth, su})equal ears, the posterior with 3 small riblets; a wellmarked though shallow byssal fold; and moderately thick valves. The right valve is more convex and strongly sculptured, bearing 29 to 3() high, narrow, T-rail shaped ribs, flattened above, overhanging narrower, deep, nearly smooth channels; and with marked concentric imbrication, feeble on top of the ribs but articularly scaW at their sides. The sculpture of the left valve is less pronounced, hidden in the matrix, but apparent similar."

DhtuKHfonn.— 192 mm.; long. 175 mm.; diameter about 35 mm.''

In the type the lateral edges are slightly defective, the submargins very narrow.

This species is close* to P, pnrisJnmenxlM and is no doubt genetically related to that form. Although the left valve of P. dUlen has not been seen, it is safe to assume from the close relationship of this species and P. ]>urfH!yiaerts!s that the left valve of the former is ornamented with narrow, ridge-like ribs which are separated by concave-bottomed interspaces relatively wider than those of the right valve.

P, diller I is so far known only from )>eds of probable upper MioccMie (although possibly lower Pliocene) age at Rio Dell, on the Eel River, Humboldt County, where the type was collected by Mr. J. S. Diller, of the United States (geological Survey.

ranc;b.

Upper Miocene or lower Pliocene. Rio Dell, Eel River, Humboldt Countv (Dall; Diller).

64 Tertiary And Quaternary Pe0Ten8 Of California.

P. (nceni is associated with the following possibly upper San Pablo (upper Miocene) fauna at the Double Eagle wells, in the Coalinga district, Fresno County: TainioHoma gregaria Phania {off')fortU Tresus (?) sp., Glycymeris patulus (?), and Sa,ridomus gibbosux. This fauna, although containing Tamiosovia gregaria lacks the two most characteristic species of the San Pablo formation of this locality, viz, Picten entrellamiH and (Mrea titan. The beds at the Double Eagle wells represent the upper part of the San Pablo as developed in the Coalinga district, so that P, oweni mav, therefore, be considered as only occurring in the upper part of the San Pablo, or, in other words, in beds tmnsitional from the San Pablo (upper Miocene) to the Purisima (lower Pliocene). Just above the first railroad bridge across Waitham Creek, Fresno County, P, mceni is associated with the following fauna in beds probably representing about the same horizon as those exposed at the double Eagle wells above referred to: Saxidovnis gihhomcs Chione n. sp. (large, coarse sculpture), and Tarnwfioina grearia.

A 17-ribbed right valve of P, oweni was found 2 miles south of San Lucas, Monterey County, associated with Pecteii estreUnns and varieties, Astrodopsis tianidiis Balinxis estrellayim etc.

Named at the request of Mr. F. M. Anderson after Josiah Owen, of Los Gatos, Cal.

Range.

Pliocene (lower). North of Purisima, San Mateo County (F. L. Hess); Olinda, Puente Hills, Orange County (Eldridge); Lonoak, Salinas Valle}-, Monterey County (U. S. Nat. Mus. locality 3830), (Hamlin); Lewis Creek, 9 miles below Priest Valley, Monterey County (locality 3833), (Hamlin). Temescal Canyon, Santa Monica Mountains, Los Angeles County (Rivers).

Miocene (upper?) Foxins, Santa Barbara County (University of California collection); Double Eagle wells, Coalinga district, Fresno County (Eldridge); railroad bridge across Wartham Creek, Fresno County (Eldridge); San Lucas, Monterey County (Hamlin; Arnold).

Pecten (Patinopecten) propatulus Conrad.

PI. VII, fig. ' PI. IX, tigs. 1, If/, 2, and 2a.

1849. Pecten propatulus Conrad, Geol. Wilkes Expl. Exped., app. 1, 1849, p. 726, pi. 18, figs. 13, 13a. 1864. PecUn propatulus Conrad, Meek, Miocene Checklist, S. I. Misc. Coll., 1864, p. 26 (Jide Dall). 1869. Pecteii propatulus Conrad, Gabb, Pal. Cal., vol. 2, 1869, p. 103. (California localities excepted.) 1888. Pecten propatulus Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 258 (in part). 1898. Pecten (Patinopecten) propatulus Conrad, Trans. Wagner Free Inst. 8ci., vol. 3, pt. 4, 1898, p. 699.

Description, — Shell averaging about 95 millimeters in altitude, as high as long, equivalve, equilateral, rather thin, somewhat ventricose and with smooth margins; base regularly rounded; sides straight and sloping at a rather low angle. Right valve w4th 15 or 16 subequal. squarish ribs, some of which are generally obsoletely medially sulcated; interspaces subequal, about as wide as ribs and sometimes containing faint intercalaries; whole surface ornamented with fine, sharp,

66 Tertiary And Quaternary Pe0Ten8 Of California.

Pecten (Chlamys) fucanus Dall. PL X, figs. 1, 2, and 2a.

1808. Pecten (Chlamys) fucanus Dall, Trans. Wagner Free Inst. 8ci., vol. 3, pt. 4, 1898, p. 704, pi. 26,

fig. 7. 1904. Pecten (Chlamys) fucanus Dall, Harriman Exped. Bepts., Alaska geology, Neozoic invert.

fossils, p. 113.

Description. — Adult shell averaging nearly 100 millimeters in altitude, about as long as high, inequivalve (the left being the more convex), equilateral, moderately thin, and with nearly smooth margins. Right valve with from 14 to 17 more or less unequal, prominent, rather squarish, radiately striate ribs, between which (especially the anterior and posterior ones) are occasionally intercalated small riblets; interspaces unequal and averaging somewhat narrower than the ribs; whole surface of disk sculptured by rather prominent lines of growth and a fine subsidiary tessellation; hinge line longer than one-half length of disk; ears equal in length; the anterior rather narrow and sculptured by 4 prominent radials and fine, imbricating, incremental lamellee; the posterior rectangularly truncated and sculptured by more, but less prominent radials and fine concentric lamellae; byssal notch profound. Left valve usually having 15 or 16 unequal, prominent, convex-topped ribs, the median one generally being stronger than the rest, with the second or third one from it on each side only a little less prominent; the prominent ribs, especially the median one, is generally surmounted by elevated imbricating scales; the other ribs are simply radially striated, as are the interspaces, which often carry one or more elevated riblets; the submargins are radially threaded, as are the subequal ears, which are rectangular}' truncated, and also bear marked concentric lamelleB; the fine subsidiary tessellation is also present on well-preserved specimens of this valve. The resilial pit is of moderate size, and the cardinal edge is deeply grooved parallel to and just below the margin. The interior of both valves reflects the external ribbing.

Dimensions. — Alt. 85 mm.; long. 80 mm.; convexity of right valve 5 mm.; of left valve 15 mm.; hinge line 50 mm.

The difference between the convexity and ribbing of the two valves, together with the variation in size, shape, and ornamentation of the individual ribs of the same valve, are the prominent characteristics of this species. It is not closely allied to any other species of Chlamys but, instead, shows in its sculpture some affinity to certain species of Patinopecten,

The type of P.fucamis (U. S. N. M., No. 107790) is the mold of the exterior and interior (a cast of the former being PI. X, fig. 2) of a left valve which was found by Mr. J. S. Diller in the Miocene sandstone on the coast just east of Clallam Bay, Clallam County, Wash. It was associated in the sandstone formation with the following species: Sigaretus sp., Crepidulu sp., Dentalixim sp., Mytilus sp., Mactra or Spisula sp., Venericardia sp., (cf.) decisa Conrad, Leda sp., Tellma (cf.) arctata Conrad, Tellina sp., Chione sp.

The writer found P, fucanus at several localities (U. S. Nat. Mus. localities 4074, 4077, 4081, 4082) on the coast between Clallam Bay and the mouth of the Pysht River, 7 miles farther east. At all of these places it was associated with

Miocene Pectens. 67

characteristic Miocene fossils, among which was a large Pecten (probably propatidua Conrad) with medially sulcated ribs on the right valve.

Miocene. Between Clallam Bay and Pysht River, Clallam County, Wash. (Diller; Arnold); north end of Popoff Island, Alaska (Dall).

Pecten (Chlamys) hamlini n. sp.

PI. XI, fig. 2.

Description, — Type somewhat distorted but originally about 60 millimeters in altitude, and probably somewhat shorter than high; modemtely convex; base evenly rounded; sides nearly straight. Right valve with 4 broad, squarish ribs, each ornamented above by about 5 prominent imbricated radiating ridges, and separated by relatively narrow interspaces; hinge line more than one-half length of disk; anterior ear much longer than posterior and ornamented by several imbricated radiating ridges; byssal notch quite prominent; posterior ear short and radially ridged.

Dimensions, — (Of the distorted type.) Alt. 60 mm.; long. 68 mm.; hinge line 40 mm.; diameter 24 mm.

This species is closely allied to P. loattsl but is distinguishable from the latter species by its relatively broader (?)disk and longer hinge line. The char* acteristics of sculpture are approximately the same in the two species.

The geologic position of P, hamlini is somewhat uncertain, although the meager fauna with which it is associated at the type localit}' points toward its correlation with the Vaqueros or lower Miocene. The type of P, fuimlini (U.S.N.M. No. 164844) was collected by Mr. Homer Hamlin near the head of Slack's Canyon, in the Mount Diablo Range, Monterey County, where it was associated with P, estrellamis Conrad, Chione n. sp. (large, and with coarse sculpture), Ohione (cf.) matheii'sonic Gabb, and Mactra (aff.) catillifornus Conrad.

A specimen, which is probably a left valve of P, hamlini was found associated with Pecten hranneri in the lower Miocene at Tuff Hill, near Stanford University, Santa Clara County. This specimen has three widely separated, narrow, ridge-like ribs, and the interspaces are ornamented b}' a number of rather coarse radiating riblet; altitude 31 millimeters.

Miocene (lower?). Locality 3851, U. S. Nat. Mus., head of Slacks Canyon, Mount Diablo Range, Monterey County (Hamlin); Stanford University (Tuff Hill), Santa Clara County (Arnold).

Pectkn (Chlamys) nutteri n. sp.

PI. XI, figs. 3, 4, and 4a.

Description, — Shell averaging about 65 millimeters in altitude, slightly higher than long, inequivalve, equilateral, more or less ventricose, and often showing

68 Tertiary And Quaternary Pecten8 Of California.

several constrictions or undulations of interrupted growth; margins somewhat coarsely serrate; base regularly rounded; sides straight, and forming an acute angle at the umbo. Right valve with about 8 to 10, unequal, mther prominent, flat- topped ribs, each of which is channeled by one or more deep, narrow, concave sulcations which divide the primary rib from umbo to margin into two or more generally unequal but evenly convex riblets; interspaces somewhat narrower than the ribs, and containing from 1 to 3 prominent rounded riblets; the riblets become more numerous and the major ribs less prominent anteriorly and posteriorly; the minor sculpture consists of S(|uamose lines of growth, which are more prominent on the ribs, and beautiful microscopic checkered tessellation which is best developed in the major and minor interspaces; hinge line from two-fifths to nearl} one-half length of disk; anterior ear prominent and sculptured by 5 or 6 elevated radiating ridges and imbricating concentric lamellae; byssal notch moderately deep; posterior ear rectangularly truncated, a little less than one-half length of anterior, and similarly but less prominently sculptured. Left valve wth unequal, rather narrow, convex ribs, the alternate ones being more prominent than those intermediate; extremities of the ribs sometimes ornamented by longitudinal riblets; interspaces of about equal width to the ribs, and ornamented by one or three alternately prominent intercalaries; surface sculptured b}' imbricating incremental lines; the constrictions, when present, are more pronounced in this valve; ears sculptured similarly to those of the right valve. Hinge with a pair of prominent Cardinal ci-ura adjacent to the umbonal pit in the right valve.

Dimemiims. — Alt. 64 mm.; long. 57 mm.; hinge line 27 mm.; diameter 21 mm.

This species is allied to P. parmdeei and P. wattHi but is distinguishable by having a larger number of ribs, which are also narrower and more coarse}' radially sculptured. The Miocene forms of P, natter! have more prominent and deeply sulcated ribs on the right valve, are generally more convex and more prominently constricted, and have relatively longer posterior ears than the later forms.

P. nutteri so far as known, ranges from the Mount Hamilton Range Miocene to the lower Pliocene. It is found rather abundantly in a certain layer in the sea cliff, one-half mile south of the mouth of San Gregorio Creek, San Mateo County, associated with a characteristic lower Pliocene (Purisima) fauna. The species is named in honor of Mr. Edward Hoitt Nutter, who has rendered the writer much valuable assistance in the preparation of this paper. The type is from San Gregorio, San Mateo County, and is now in the collection of the department of geology, Stanford University.

Range.

Pliocene (lower). Purisima to Pescadero, San Mateo County (J. P. Smith, W. R.

Hamilton, Arnold); Kreyenhagen's ranch, Fresno County (Watts). Miocene (upper). Near Mount Hamilton, Santa Clara County (No. 5805, Cal. St.

Min. Bur. Coll., collected by Mrs. A. E. Bush).

Miocene Pegtens. 69

Pecten (Chlamys) sespeenjsis n. sp.

PI. VIII, ligs. 2, 2a, and 3.

1888. Pecten hastntim Coor (not Sowerby), Seventh Ann. Rept. Cal. St. Min., 1888, p. 257 (Miocene of Estrella, San Luis Obispo County?).

Descri-ption. — Shell averaging about 50 millimeters in altitude, higher than long, inequivalve but both valves equally slight]}' convex, rather thin, and equilateral, except for ears. Right valve with about 9 pairs of narrow, rounded, nearly smooth ribs, each pair being separated from the adjacent ones by interspaces, which are general slightly wider than the interspace between the members of the pair; surface sculptured by incremental lines; hinge line about two-thirds length of disk; anterior ear much produced, sculptured by several prominent radials and numerous incremental lines; posterior ear over one-half as long as anterior, and sculptured similarly; byssal notch prominent. Left valve with about nine prominent, narrow, squarish, somewhat convex-topped ribs separated by much broader interspaces, along the bottom of which run one or more thread-like intercalaries of greater or less prominence; ears similar to those of the right valve.

Dhnenshm. — Alt. 37 mm.; long. 30 mm.; hinge line 19 mm.; diameter 12 mm.; umbonal angle 75.

This species is closely allied to, and is probably the precursor of P. hastatus Sowerby. It corresponds to P, hastatm in size, shape, and number of major ribs, but differs from the latter in having longer anterior ears and scarcel} any secondary sculpture of minor riblets and scaly surface. P, sespeensis approaches more closely to the smooth form of P, hastatus found in the Pliocene, but may be easily distinguished from that form by its longer posterior ears and lack of much secondary sculpture.

The only specimens of this species known are rather poorly preserved casts, with now and then small fragments of the shell hanging to them, which come from beds of lower Miocene age, locally known as "oil rocks," in the Sespe oil district, Ventura County. Type and cot3pe, No. 12480, California State Mining Bureau. Other specimens of the same species, Nos. 12427 and 14759 C. S. M. B. On Tar Creek, Ventura County, Mr. found P. sespeetisis associated with Turritdla (cf.) hoffrruinni Ostrea sp., and Mod!olu.H sp.

Miocene (lower.) Sespe oil district, Ventura County (Watts); Tar Creek, Ventura County (Eldridge).

Pecten (Chlamys) sespeensis var. hydei n. var.

PI. V, figs. 8, :ki, and 86. 1903. Pecten (ChlamyK) hydei Arnold. MS.

Desc7*option. — Shell averaging about 45 millimeters in altitude, much higher than long, subequivalve, slightly convex, and subequilateral, except for ears; anterior sides more concave than posterior; base regularly rounded; umbonal angle

70 Tertiary And Quaternary Pecten8 Of California

comparatively small. Right valve with about 20 subequal, prominent, rounded, somewhat imbricated ribs, which increase gradually in number by division and intercalation as the shell grows; inteispaces somewhat narrower than ribs and often containing one or two thread-like intercalaries; eai*s as in P. liastatxis var. herwixia except less imbricated, and the posterior relatively larger. Left valve similar in every respect to right.

Dimensions, — Alt. 46 mm.; long. 39 mm.; diameter 13 mm. ; umbonal angle 82.

This variety is characterized by the nearly uniform size of its ribs and interspaces. The shell ha& a tendency to contract somewhat upon reaching an altitude of about 35 or 40 millimeters. var. hydel is closely allied to the typical P. sespeensh but may usually be distinguished by its more nearly equal ribs, which are generall} more strongly imbricated.

In a tributary of Little Sespe Creek, Ventura County, Mr. Eldridge found P. var. hydi associated with Seutellu fairbanhm Ostrea sp.. Area sp., and Balanus. Near the Torrey wells, Ventura County, the same gentleman found it with MytUus mathevMonii and Ostrea (aff.) titan. In the Ojai Valley it occurs with Pecten magnolia and Chione n. sp. (large; coarse sculpture).

The type specimen is from Lynch's Mountain, Monterey County, where it was found associated in the lower Miocene (Vaqueros sandstone) with TwiteUu hoffniannl, Pecten estvellanus and other species characteristic of this horizon. It is now in the collection of Delos Arnold. Named in honor of Prof. James M. Hyde, of the University of Oregon.

Range.

Miocene (lower). L3'nch's Mountain, Monterey County (Arnold); vicinity of Little Sespe Creek, Torrey oil wells, and Ojai Valley, Ventura County (Eldridge).

Pecten (LYROPEcrrEN) bowers n. sp.

PI. XII, tigs. 1 and 2; PI. XIII, figs. 1 and la.

1856. ? Pedm mvadanus Conrad, Pac. R. R. Rept., vol. 5, p. 329, pi. 8, fig. 77.

Description, — Shell averaging about 150 millimeters in altitude and length, inequivalve, equilateral, rather thick, ventricose, and with smooth margins; base regularly rounded; sides sloping, the anterior ones slightly concave upward. Right valve considerably less ventricose than left, the surface of the disk being almost flat until an altitude of 50 or 60 millimeters is reached, when it begins to be more or less convex; surface ornamented with about 18 subequal, prominent, rounded ribs, which, with the interspaces, are radiately striate and crossed by fine wavy incremental lines; the ribs tend to become smaller toward the sides of the disk, there being a varying number of riblets near the sides in different specimens; interspaces subequal, round bottomed, about as wide as the ribs, and sometimes containing an auxiliary riblet; hinge line about three-fifths length of shell; ears about equal in length, anterior ear divided into two nearly equal parts by a line radiating from the apex, the part above the dividing line being ornamented by 3 or 4 radiating ribs and concentric lines while the lower part (byssal area) is ornamented by imbricating incremental lines which are convex

Miocene Pecten8. 71

toward the apex; byssai notch wide and of medium depth; posterior ear rectangularly truncated, radiately ribbed, and crossed b}" concentric incremental lines. Left valve prominently and evenly ventricose; sculptured the same as the right valve except that most of the interspaces contain an auxiliary riblet; anterior ear arcuate ended, radiately ribbed, and with concentric incremental sculpture; posterior ear as in right valve.

Dirtienshms. — Alt. 150 mm.; long. 150 mm.; hinge line (restored) 90 mm.; diameter 55 mm.

This species is distinguishable by its large size, almost smooth rounded ribs, and the greater convexity of the left valve. The flat surface of the right valve, near the apex is also a very noticeable chamcteristic. P. bowers is placed in the section Lyropecten because of its hinge and general aflinity to the group. It, however, lacks the radial secondary sculpture found developed to a greater or less degree on most of the species of this group, and is also different from the other members examined by the writer in having the left valve noticeably the more convex.

P. Jxrwersi ranges from the lower to possibl} the middle Miocene, being found associated in some localities with P. magnolia and in others with P, discs.

The type which is figured is from Santa Inez Canyon, Santa Barbara County, and is now in the collection of the University of California. Named in honor of Dr. Stephen Bowers, of Los Angeles, one of the pioneer geologists of southern California, to whom the writer is indebted for much valuable material and information used in the preparation of this paper.

Range.

Miocene (middle?). Gillis's ranch, 10 miles southwest of Paso Robles, San Luis Obispo County (J. P. Smith).

Miocene (lower). Santa Inez Canyon, Santa Barbara County (Voy; J. H. Wilson); La Panza Creek, San Luis Obispo County (Fairbanks; R. Moran; Arnold); Barker ranch, and "top of hill" at Long Tom mine and Miller Bros, ranch east of Annette P. O., Kern County (Watts; Arnold); 30 miles north of Santa Monica and 1 mile from ocean, Ventura Count} (R. E. Maynai-d); Santa Monica Mountains, Los Angeles and Ventura counties (Bowers). Station No. 550, Santa Ana Mountains (Watts).

Pecten (Lyropecten) crassicardo Conrad. PI. XVI, figs. 1 and 1; PL XVII, figs. 1, la, and PI. XVIII, figi?. 1, 2, and 2a.

1856. PaUium erf uffticnrdo Conmd Proc. Nat. 8ci. PhUa., 1856, p. 313.

1857.? Spondylus [=IWten] EstraUemis Conrad, Proc. Acad. Nat. Sci. Phila., first series, vol. 8, for

1856, 1857, p. 315. 1857.? Spondylus [ Peclen] Jtrellaniis Conrad, Pac. R. R. Rept., vol. 7, 1857, p. 191, pi. 1, fig. 3; not

Pallium l=Pedeu] eMrellmmm Conrad, Pac. R. R. Repc, vol. 6, pt. 2,1856, p. 71, pi. 3, fig. 15. 1863. PecUn crassicardo Conrad, Proc. Acad. Nat. Sci. Phila., 1862, p. 291. 1867. Lyropecten crassicardo Conrad, Am. Jour. Conch., vol. 3, 1867, p. 6. 1869. Liropecten crassicardo Conrad, Gabb, Pal. Cal., vol. 2, 1869, p. 105 (in part, at least). 1888. Liropecten crassicardo Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 246 (in part,

at least).

i2 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA.

ISH. PecUn eMreUanus Conrad, Cooper, Bull. Cal. St. Min. Bureau, No. 4, pt. 5, 1894, p. 67 (in part). 1898. Pectm magnolia Dall, Trans. Wagner Free Inst. Soi., vol. 3, pt. 4, p. 702 (in part); not Pecten

magtiolia Conrad, Pac. R. R. Rept, vol. 7, 1857, p. 191, pi. l,.fig. 2. 1901- PecUn magnolia Dall, Nautilus, vol. 14, 1901, p. 117 (in part); not P. magnolia Conrad, 1857. 1904. Pfcim diaUoensis Arnold, MS. (a distorted specimen of P. crassirarflo being the

type).

Descriptitm, — Adult, shell averaging about 130 millimeters in altitude, about as long as high, inequi valve, convex, equilateral (except for ears), thick, and generally prominently and abruptly constricted or undulated one or more times near the umbo and .sometimes at later stages of growth; sides nearly straight; base regularly rounded; margins smooth. Right valve with 14 to 17 prominent, perpendicular- .sided, convex-topped ribs, which are separated b}' more or less deeply channeled, flat-topped, convex-bottomed interspaces somewhat narrower than the ribs; whole surface of ribs and interspaces sculptured by numerous radial stria3 and fine, minutely wavy, imbricating, concentric lines; hinge line about four-sevenths length of disk; anterior ear somewhat produced, subarcuate laterally and sculptured by about 5 prominent radial ridges and numerous fine imbricating incremental lines; posterior ear about three-fourths length of anterior, sculptured similarly, but .slightly less prominently, and rectangularly truncated. Left valve similar to right, except that the ribs are narrower, and the interspaces correspondingly broader; ears similar to posterior one of right valve. Hinge with a deep resilial pit, on each side of which are several prominent lateral crura or teeth.

Du/ienshnx,— 140 mm.; long. 188 mm.; hinge line 85 mm.; diameter 50 mm.; angle 105.

The tops of the ribs sometimes overhang the interspaces and also sometimes appear smooth. Great variation is shown in regard to the luuuber, abruptness, and prominence of the constrictions on the disk. One or two are generally present near the umbo in most specimens, and some show as as six or seven at different periods of growth. The specimens of this species from Orange County are generally freer from constrictions and the disks are usually more compressed than in the forms from central California; otherwise the former are normal types.

P. crdHHicardo is characterized by its comparatively few ribs, which, with the interspaces, are more or less prominently striated. It is distinguishable from P. iVihJeyt its relatively much greater length, fewer ribs, and tendency to be constricted at different stages of growth; distinguishable from P, marfnolla with which it is often confused, by its more numerous and much narrower ribs, relatively shorter hinge line, more prominently striate (rs, and its tendency to become constricted; distinguislmble from P. eatrellanm with which it is often associated, by its fewer and rather finely striate ribs and lack of a major intercalary riblet (the bottoms of the interspaces of P. cr/jw/ca/vfo being striate rather than containing a riblet). Some of the lateral ribs and interspaces, and the surface near the periphery of the disk in adults of P, estrellaniis generally show sculpture similar to that characteristic of P. crasHicardo.

P, crassicardo is found abundantly in the San Pablo, or upper Miocene formation of central California, and also in beds of possibly lower Miocene age in southern California.

Miocene Pectens. 73

Mr. Homer Hamlin and the writer found P, crasslcardo associated with the following fauna in beds of somewhat uncertain age, in a small ravine one-half mile south of J. C. Griffin's ranch house, Nest Valley, Montere} County; dhciis Conrad, Agasoma {aff.) larltrianum Cooper, 2Iyt!luH inath&wsonli Gabb, Verttis perte7iuk Gabb, and Ontrea titan Conrad.

In the Valcito Valley, Fresno County, Mr. H. W. Turner found P. crasdeardo with Yenus pertenaiH Doninla ponderona and Tellina sp.

Mr. Eldridge found P, crasicardo associated with the following species in beds of probable lower Miocene age on the ridge between the Upper and Lower Ojai valleys, Ventura Count}': Pecten lomjtocensis Tumtella {cf.) hoffmanni Phacoides sp. (flat), Nassa sp., Dental luin sp., Cftione Leda sp, Ba/anus sp., and Tritanium or Iwas sp.

Dr. Stephen Bowers has found P. crassicardo with the following species in the Miocene of Laguna Canyon, San Joaquin Hills, Orange County: Pecten estrellaniis Glycymeris ? sp., Twnitella Jwjfrnatnii Oh lone n. sp. (large, coarse sculpture), and Gyrodea ? sp.

A beautiful specimen of P. crassicardo in the National Museum (No. 154154) labeled from '' California " is associated in the matrix with Saxidomun graciliH Tresus nuttalli and Litorina reniondi. As the last mentioned species is found only at Kirker Pass it is safe to assume that this magnificent specimen (which is figured) is from that locality.

The type of P, (PI. XVIII, fig. 1), which is now in the collection of the Philadelphia Academ} of Natural Sciences, is simply labeled "California. Pres. by Dr. Wilson.-'

Range.

Miocene (upper). San Pablo Bay, Contra Costa County (Merriam, Arnold, and others); Kirker Pass, Contra Costa Count} (U. S. N. M.); Mount Diablo, Contra Costa County (Pioche collection, Univ. Cal.); Scott Valle} Santa Cruz County (Miss L. J. F. Hecox); Cammatta ranch and San Juan Valley, east of San Luis Obispo, San Luis Obispo County (Fairbanks, Moran, Arnold); Priest Valley, Monterey County (Hamlin, Arnold); San Ardo, Monterey County (Fairbanks, Hamlin, Anderson, W. C. Dudley- for Cal. St. Min. Bureau, Arnold); Quail water Creek, San Luis Obispo County (Anderson); Ventura County (No. 12772, C. S. M. B.); Sunset district, Kern County (Eldridge); Valcito Valle} Fresno County (Turner).

Miocene (middle or lower). Devils Den, Kern Count\; Ojai Valley, Ventura County (Eldridge); ? El Toro and Laguna Canjon, Orange County (Bowers, Arnold).

Pecten (Lyropecten) Crassu ardo Conrad var. hamiltoni n. var.

PI. XI, fijrs. 5 and

Description, — Adult shell averaging about 60 in altitude, subequivalve, equilateral, convex; sides concave above; margins smooth. Right valve with 15 to 17 prominent convex-topped ribs, separated by interspaces narrower

Miocene Pecten8. 75

1888. Liropecten estrellanus Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 246.

1894. TAropecten estrellanus Conrad, Cooper, Bull. Cal. St. Min. Bureau, No. 4, pt. 5, 1894, p. 57, pi. 5.

figs. 65-67 (text only in part). 1898. Pectm (Lyropecten) Heermanni Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 701

(not P. Heermanni Conrad, Proc. Acad. Nat. Sci. Phila., vol. 7, 1855, p. 267, which is P,

caurinus Gould).

Description, — Shell avei-aging about 90 millimeters in altitude, somewhat longer than high, equivalve, equilateral, of medium thickness, generally quite ventricose, and with margins more or less sen-ate; base evenly rounded; sides sloping, slightly concave above. Right valve with 16 to 20 prominent, squarish ribs separated by channeled interspaces which are narrower than the ribs; interspaces each with one sharply outlined, squarish riblet in the middle; surface sculptured by fine raised incremental lirulte which loop back over the ribs and riblets, and, on the anterior and posterior portions of the disk, by radiating striae, which increase in number as the periphery of the disk is approached; hinge line straight and nearly equal to one-half length of disk; ears equal; anterior ear arcuate in front and ornamented above area by three or four radiating ridges and numerous incremental lines; byssal notch sharply defined; byssal area with incremental sculpture only; posterior ear with slightly concave end and ornamented by 5 or 6 radiating ridges and more or less prominent incremental lines. Left valve with the ribs narrower and having more sloping sides and rounded tops than those of the right; interspaces wider; auxiliary riblets inclined to be dichotomous near the ends in the more mature specimens; the looping incremental lirulsB and the secondary radiating lines apparently more highly developed in this valve than in the right; ears similar to the posterior ear of the right valve.

Dimensions. — Alt. 93 mm.; long. 105 nmi.; hinge line 50mm.; diameter 47 mm.

This is a most variable species in size, shape, and sculpture, the above description applying to the most common form. One peculiar characteristic sometimes shown by this species is a contraction or interruption in the growth at different stages. See PI. XXI, figs. 1, la, li. Up to the first interruption the sculpture is generally simple and quite constant, but afterwards it (especially the radial) becomes more complex, the riblets in the interspaces becoming dichotomous and the radiating lines becoming more numerous and prominent.

The variety of this species described as Lyropecten by Conrad is the extremel}' convex type. Conrad thought that the valves were unequal in the very convex shell, but in all the specimens of this sort examined by the writer, both valves show an equal amount of convexit3 This very ventricose form is common near Coalinga, Fresno County, in beds of probable San Pablo (upper Miocene) age.

Specimens of this species from Catalina Island show more ribs (right valves, 19 to 21) than the average, and also appear to be slightl} inequi valve, the left valve being the more ventricose. The characteristic interruption and constriction took place on most of the Catalina specimens at an altitude of about 55 millimeters.

A specimen of this species from San Benito County, collected by Mr. H. W. Turner, is very convex, and shows beautiful equal, equidistant, looped lamellae over the surface of the valve. The intercalary riblets on this specimen are sharply defined.

76 Tertiary And Quaternary Pecten8 Ob California.

Between San Lucas and San Ardo, Monterey County, Mr. Homer Hamlin found a specimen of P, estrelUmm measuring 125 millimeters in altitude, which shows the striations well developed on the anterior and posterior ribs and near the ends of the middle ribs and interspaces. The flat forms grading into var. cataZirue were found associated at this locality with the typical convex shells.

In central California, especial in the region about the Salinas Valley, the P. estrellanus associated with the large Ostrea titan Conrad usually have nineteen ribs, while those found in the horizon of Ostrea palvuda Carpenter and Chorxis htlherl Hinds average two or three less. The latter horizon appears to be above that of O. titan.

In the region around Coalinga, Fresno County, P, estrellaruts is very common, and is usually associated with Tarniosmna ijregaria, Ostrea titan Venus pertenuis Chione n. sp. (large; coarse sculpture), Area canal etc., in beds which may be the equivalent of the San Pablo formation. The significance of the total absence of P. estrelhuuM from the type locality of the San Pablo is not at present known.

So far as is definitely known, this species is confined to the Miocene, where it is found in nearly ever}" county of California from Napa to Orange. In some places it is found associated with a characteristic lower Miocene fauna, while at others the same form will be found in the San Pablo or upper Miocene.

Range.

Miocene. Napa County (Lockwood); Solano County (Cooper); Alameda County (Yates); Mount Hamilton Range (J. P. Smith; Arnold); Santa Cruz Mountains (Ashley; Arnold); San Lucas and San Ardo, Monterey Count}' (Anderson; Hamlin); Lynch's Mountain, Monterey County (C. S. Smith); 15 miles northeast of San Miguel, Monterey County (Hamlin; Arnold); San. Luis Obispo and Santa Barbara counties (Conrad; Fairbanks; R. Moran; J. H. Wilson; Arnold, and others); Coalinga, Fresno County (Watts; Eldridge; L. D. O'Neal); San Benito County (Turner); Santa Ana Range, Orange County (Watts); El Toro, Orange County (Bowers).

Pecten (Lyropecten) ESTRELLANUS Conrad var. catalin n. var.

PI. XX, figs. 3, 3a, and 4.

Description. — Shell averaging about 65 millimeters in altitude, considerably longer than high, equivalve, equilateral, of medium thickness, only slightly ventricose, and with margins more or less serrate; base evenly rounded; sides only slightly concave above. Right valve with 19 or 20 square, flat-topped ribs, all of which are sculptured by incremental lines and the 3 or 4 outer ribs on each side by more oi* less prominent radial lines; interepaces narrower than ribs and ornamented by a prominent squarish riblet; hinge line over one-half length of disk; anterior ear arcuate in front, with rather small byssal notch, and ornamented by concentric lines and 5 or 6 rather prominent radiating ridges; posterior ear with concave end and ornamented by numerous fine radiating ridges and incremental lines. Left valve similar to right except that the ears are both like the posterior one of the right valve, and the interspaces are relatively a little wider.

Miocenk Pectens. 77

Dimensions. — Alt. 62 mm.; long. 72 mm.; hinge line -10 mm.; diameter 12 mm.

This species is similar in general characteristics to the typical P, estrellanus but differs from it in being much flatter, having a relatively much longer hinge, and, on the average, more ribs. The characteristic constriction of P, estrellaniis is also lacking in this variety, so far as known.

P. var. catalim ranges from the upper Miocene to the Pliocene. On Santa Catalina Island it is associated with the typical P, estrellanm in beds which are probably upper Miocene, while at Temescal Canyon, near Santa Monica, it is associated with the well-known Pliocene species P. stearnsii P, cerrosensi and Laqaeus calif'nicus (or Jeffrey si).

The type, which is figured and is now in the collection of Delos Arnold, was found in a limy matrix near the isthmus, Santa Catalina Island, Los Angeles County, by Mr. F. H. Thurston.

Range.

Pliocene (lower). Temescal 'Canyon, Santa Monica Mountains, Los Angeles County

(Watt). Miocene (upper). Isthmus, Santa Catalina Island, Los Angeles County (Thurston,

Mrs. Trask);? San Ardo and vicinity, Montere}" County (Hamlin, Andei*son).

PeCTEN (LyROPECTEX) E8TKKI.LANUS CONRAD Var. TERMINUS U. Var.

PI. XXIII, figs. 2 and 2a.

Description. — Shell averaging about 70 millimeters in altitude, somewhat longer than high, ventricose, subequivalve, equilateral; margins coarsely serrate. Right valve with about 15 prominent, squarish ribs, separated by narrower channeled interspaces, in each of which runs a prominent intercalary; surface of ribs and interspaces obsoletely radially striate; hinge line more than one-half length of disk; ears subequal, the anterior strongW radially ribbed, the posterior with finer sculpture; ssal notch deep and rather narrow. Left valve similar to right, except that the ribs are relativel}- narrower.

Dimensiims. — Alt. 70 mm.; long. 75 mm.; hinge line 48 mm.; diameter 32 mm.

This variet}" is distinguishable from the typical form by its fewer and broader ribs, relatively longer hinge line, and finer obsolete radial striation; and from var. catalina b}" its fewer ribs and greater convexity.

The type of P. var. terminus is from the upper Miocene or San Pablo horizon of Monterey County, and is now in the collection of the University of California.

Range.

Miocene (upper). Monterey County (University of California).

Pecten magnolia Conrad.

PI. XXIV, tigs. 1 and 2; PI. XXV, fig. 1.

1857. Pecten magnolia Conrad, Pac. R. R. Kept., vol. 7, 1857, p. 191, pi. 1, tig. 2.

1888. Llropecten veatchii Cooper (nut of Seventh Ann. Kept. Cal. St. Min., 1888, p. 246

("Pliocene, Ojai Valley"). 1898. Pecten magnolia Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 702 (in part). 1901. Pecten viagiwlia Dall, Nautilus, vol. 14, 1901, p. 117 (in part.)

78 Tertiary And Quaternary Pecten8 Of California.

Description. — Shell averaging about 150 millimeters iu altitude, slightly longer than high, subexjuivalve, equilateral, rather thick, somewhat ventricose, and with smooth margins; base regularly rounded; sides sloping above, and slightly concave. Right valve slightly more convex than left, with about 9 to 11 broad, flat-topped, equal, equidistant ribs; interspaces slightly narrower than ribs and flat-bottomed; whole surface of ribs and interspaces covered by imbricated radiating riblets (about 10 on each rib) and fine, concentric incremental lines; hinge line about two-thirds the length of the disk; anterior ear slightly longer than the posterior, with arcuate end and fine concentric incremental sculpture, but obsolete radiating ridges; posterior ear with no radial sculpture whatever; b3's8al notch relativel} small. Left valve quite similar to right but with narrower, more rounded ribs; sculpture of radiating riblets and fine wavy incremental lines; interspaces broader than in right valve; ears almost identical to those of right.

DimsnsioTis, — Alt. 146 mm.; long. 150 mm.; hinge line 105 mm.; diameter 65 mm.

The original description and figure of this species are poor, but there is no question in the writer's mind as to which species Conrad applied this name. There is no other large Pecteii in the Miocene of the West Coast having the small number and characteristically large, striate ribs, and ears with so little radiate sculpture. The figure of the type, poor as it is, shows that there was little or no radiate sculpture on the ears of the specimen or specimens serving as the type for the drawings. Furthermore, there is no other Peaten except the species above described, which would bring out the following comment, which Conrad, in his original description, applied to P, magnolia:

''This species will compare in size with P, Jeffermninf Say, and is so remarkably similar to it that it may prove to be the same' species when more perfect specimens are collected."

The specimens which served the types for Conrad's P. magnolia are in the U. S. National Museum (Nos. 13311 and 18325), and came from the Santa Inez Mountains, Santa Barbara County. Although much broken, these specimens show the ribbing and sculpture of the original shell almost perfectly.

In many of the worn specimens of this specie the radiating striae have been lost, and the ribs appear smooth. Internal casts show smooth rounded ribs for both valves. The distinguishing characteristics of this magnificent species, some of which attain an altitude of over 210 millimeters, are its size, small number and equality of ribs, equality} of ears, and almost total lack of any radiating sculpture on the ears.

P, m.agnolUi is somewhat closely allied to P, cramicardo and is no doubt its precursor. It is distinguishable from the latter by its fewer (9 to 11, instead of 14 to 17), broader, more square-cut and more coarsely radially sculptured ribs, and the obsolete radial sculpture on its ears.

P, magnolia is one of the most characteristic of the lower Miocene, or Vaqueros formation, fossils. In the region around Mindego Hill, San Mateo County, it is found in the Vaqueros sandstone associated with the following fauna: Agas&ma harkerianum Agawma {cf,) gravida Agaso7na I'eniianum, Area (cf.) microdonta

Miocene Pecten8. 79

Balanus (cf.) estrellanus Cardiwn {Trachycardmm) n. sp., Chione matheiosonl! Chione n. sp. (large; coarse sculpture), Crepidula princeps Chima hiplicdta Dosinia conradi Doainia mathews/nii., Dosinia {cf,) mo7itana Dosinia {off.) ponderosa Odleru8 (aff,) eccentriciis Olycyineris n. sp. (large), Pimcoides acutilhieatns Phacoides richthofeni Mytilus niatheicsoiiU N&verita recluzmna Ostrea (of.) tita7i Panopea generosa Pecten estreUanus Pecten {Plagiocteniuin) Soleii slcariua Tivela ineziana, Trochita costdlata Turritella fvoffmanni. On the south fork of the lower Ojai Valley, Ventura County, Mr. Eldridge found P. magnolia associated with Chione n. sp. (large; coarse sculpture), Mytilus rtiathewsonii Turritell'a hoffmann! Pecten sespeensis var. hydei and other lower Miocene forms.

Miocene (lower). Mindego Creek, 10 miles south of Stanford University (Arnold); Corral de Piedra Creek, San Luis Obispo County (I. H. Wilson; Robert Moran; Fairbanks); Hazard Canyon, 12 miles southwest of San Luis Obispo (N. H. Drake); Morro and Toro creeks, San Luis Obispo County (Fairbanks; R. Moran); Santa Inez Mountains, Santa Barbara County (Conrad); near Oceanic quicksilver raise, San Simeon, San Luis Obispo County (L. Wagner); Ojai Valley, Ventura County (Eldridge).

Pecten (Lykopecten) miguelensis n. sp.

PI. XXIT, figP. ], la, and 16; PL XXIIl, fig. 1.

1898. Pecten (Lipropecten) Heennanni Dall, (not Conrad) , Trans. Wagner Free Inst. Sci., vol. 3, pi. 4. p. 701. (Specimens in U. S. Nat. Mus., No. 6397, lat:K5led P. Heerrnanni by Conrad; PI. XXIII, fig. 1.)

Description, — Shell averaging about 110 millimeters in altitude, about as long as high, inequivalve, subequilateral, rather thin, and with margins more or less serrate; base rounded; sides slightl} concave above, the posterior being slightl} longer than the anterior. Right valve more convex than the left, with 17 or 18 prominent rounded ribs, each sculptured by several (10 or 11 at extremist}- of ribs in type) distinct radiating raised riblets and numerous sharp, minutely wavv, incremental lines; interspaces narrower than ribs, and containing by a prominent radial auxiliary rib,* which is ornamented by the incremental sculpture, and toward the periphery of the disk, by two or more radiating riblets as in the large ribs; hinge line somewhat longer than one-half the length of the disk; anterior ear arcuate in front, with small byssal notch, and sculptured by 5 or 6 prominent, rounded, radiating ridges and numerous sharp, concentric lines; posterior ear with 10 or 11 radiating riblets and fine incremental sculpture. Left valve less ventncose than the right, but otherwise similar to it, except that the ribs are slightly narrower and the interspaces relatively broader; ears similar to those of the right valve except that the anterior one lacks the byssal notch.

Dimnswns, — Alt. 107 mm. ; long. 110 mm. ; hinge line 60 mm. ; diameter 50 mm.

This species is distinguishable from P, estreUanus and others of the same group by its larger size, inequality of valves (which are more or less inequilateral), and radially striate surface from umbo to periphery. It sometimes shows the constric-

70 Tertiary And Quaternary Pecten8 Of California

comparatively small. Right valve with about 20 subequal, prominent, rounded, somewhat imbricated ribs, which increase gradually in number by division and intercalation as the shell grows; interspaces somewhat narrower than ribs and often containing one or two thread-like intercalaries; ears as in P. hastatua var. hericiuB except less imbricated, and the posterior relatively larger. Left valve similar in every respect to right.

DimenHions. — Alt. 46 mm.; long. 39 mm.; diameter 13 mm.; umbonal angle 82.

This variety is characterized by the nearly uniform size of its ribs and interspaces. The shell hasa tendency to contract somewhat upon reaching an altitude of about 35 or 40 millimeters. P, var. hydci is closely allied to the typical P, sespeensis but may usually be distinguished by its more nearly equal ribs, which are generally more strongly imbricated.

In a tributary of Little Sespe Creek, Ventura County, Mr. Eldridge found P. var. hydei associated with Scutellu fairbanksi Ostrea sp., Area sp., SLud Balanus. Near the Torrey wells, Ventui*a County, the same gentleman found it with MytUua matheay%oiiii and Ostrea (aff.) titan. In the Ojai Valley it occurs with Pecten magnolia and Chimie n. sp. (large; coarse sculpture).

The type specimen is from Lynch's Mountain, Monterey County, where it was found associated in the lower Miocene (Vaqueros sandstone) with TurriteUa hoffmanni Pecten estrellanus and other species characteristic of this horizon. It is now in the collection of Delos Arnold. Named in honor of Prof. James M. Hyde, of the University of Oregon.

Range.

Miocene (lower). Lynch's Mountain, Monterey County (Arnold); vicinity of Little Sespe Creek, Torrey oil wells, and Ojai Valley, Ventura County (Eldridge).

Pecten (LYROPEcrrEN) bowers n. sp.

PI. XII. figB. 1 and 2; PI. XIII, figs. 1 and la.

1856. ? Peden imudanus Conrad, Pac, R. R. Rept., vol. 5, p. 329, pi. 8, fig. 77.

Description. — Shell averaging about 150 millimeters in altitude and length, inequivalve, equilateral, rather thick, ventricose, and with smooth margins; base regular}' rounded; sides sloping, the anterior ones slightly concave upward. Right valve considerably less ventricose than left, the surface of the disk being almost flat until an altitude of 50 or 60 millimeters is reached, when it begins to be more or less convex; surface ornamented with about 18 subequal, prominent, rounded ribs, which, with the interspaces, are obsoletely radiately striate and crossed by tine wavy incremental lines; the ribs tend to become smaller toward the sides of the disk, there being a varying number of riblets near the sides in different specimens; interspaces subequal, round bottomed, about as wide as the ribs, and sometimes containing an auxiliary riblet; hinge line about three-fifths length of shell; ears about equal in length, anterior ear divided into two nearly equal parts by a line radiating from the apex, the part above the dividing line being ornamented b\' 3 or 4 radiating ribs and concentric lines while the lower part (byssal area) is ornamented b}' imbricating incremental lines which are convex

Miocene Pecten8. 71

toward the apex; hyssal notch wide and of medium depth; posterior ear rectangularly truncated, radiately ribbed, and crossed b}' concentric incremental lines. Left valve prominently and evenly ventricose; sculptured the same as the right valve except that most of the intervspaces contain an auxiliary riblet; anterior ear arcuate ended, radiately ribbed, and with concentric incremental sculpture; posterior ear as in right valve.

Dimemlons, — Alt. 150 mm.; long. 150 mm.; hinge line (restored) 90 mm.; diameter 55 mm.

This species is distinguishable its large size, almost smooth rounded ribs, and the greater convexity of the left valve. The flat surface of the right valve, near the apex is also a ver}' noticeable characteristic. P, hoversi is placed in the section Lyropecfen because of its hinge and general aflinity to the group. It, however, lacks the radial secondary sculpture found developed to a greater or less degree on most of the species of this group, and is also diflferent from the other members examined the writer in having the left valve noticeably the more convex.

P, hncersi ranges from the lower to possibly the middle Miocene, being found associated in some localities with P, laaguoUd and in others with P, disciis.

The type which is figured is from Santa Inez Canyon, Santa Barbara County, and is now in the collection of the University of California. Named in honor of Dr. Stephen Bowers, of Los Angeles, one of the pioneer geologists of southern California, to whom the writer is indebted for much valuable material and information used in the preparation of this paper.

Range.

Miocene (middle if). Gillis's ranch, 10 miles southwest of Paso Robles, San Luis Obispo Count} (J. P. Smith).

Miocene (lower). Santa Inez Canyon, Santa Barbara County (Voy; J. H. Wilson); La Panza Creek, San Luis Obispo County (Fairbanks; R. Moran; Arnold); Barker ranch, and ''top of hilF' at Long Tom mine and Miller Bros, ranch east of Annette P. O., Kern County (Watts; Arnold); 30 miles north of Santa Monica and 1 mile from ocean, Ventura Count}' (R. E. Maynai'd); Santa Monica Mountains, Los Angeles and Ventura counties (Bowers). Station No. 550, Santa Ana Mountains (Watts).

Pkcten (Lyhopecten) crassicardo Conrad. PI. XVI, figs. 1 and la; PI. XVII, tigs. 1, 1, and Ih- PI. XVIII, figs. 1, 2, and 2a.

1856. Pall turn muiHinirdo ConTud, Proc. Acad. Nat. Sci. PhUa., 1856, p. 313.

1857.? Spondi/lut [=P<'r/e?j] Estrallemi Conrad, Proc. Acad. Nat. Sci. Phila., first series, vol. 8, for

1856, 1857, p. 315. 1857.? Spoyidylus l Perten] Estrdf atut Conmd, Pac. R. R. Rept., vol. 7, 1857, p. 191, pl. 1, fig. 3; not

Pallium [=Perfen] cdrdhtnum Conrad, Pac. R. R. Repc, vol. 6, pt. 2,1856, p. 71, pl. 3, fig. 15. 1863. Pecteri cnmicardo Conrad, Proc. Acad. Nat. Sci. Phila., 1862, p. 291. 1867. Lyropecten craMicardo Conrad, Am. Jour. C/Onch., vol. 3, 1867, p. 6. 1869. Liropect en crassicardo Conrad, Gabl), Pal. Cal., vol. 2, 1869, p. 105 (in part, at least). 1888. Liropecten crassicardo Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 246 (in part,

at least).

72 Tertiary And Quaternary Pectens Of California.

1894. estrellanns Conrad, Cooper, Bull. Cal. St. Min. Bureau, No. 4, pt. 5, 18d4, p. 67 (in part). 1898. Pecten magnolia Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, p. 702 (in part); not Pecten

maipwlia ConT&dy Pac. R. R. Rept., vol. 7, 1857, p. 191, pi. l,,fig. 2. 1901. Pecten magnolia Dall, Nautilus, vol. 14, 1901, p. 117 (in part); not P. magnolia Conrad, 1857. 1904. Pecten {Lyropecten) diabloenm Arnold, MS. (a distorted specimen of P. cramcardo being the

type).

Descriptum, — Adult, shell averaging about 180 millimeters in altitude, about as long as high, inequivalve, convex, equilateral (except for ears), thick, and generally prominently and abruptly or undulated one or more times near the umbo and sometimes at later stages of growth; sides nearly straight; base regularly rounded; margins smooth. Right valve with 14 to 17 prominent, perpendicularsided, convex-topped ribs, which are separated by more or less deep' channeled, flat-topped, convex-bottomed interspaces somewhat narrower than the ribs; whole surface of ribs and interspaces sculptured by numerous radial striae and fine, minutely imbricating, concentric lines; hinge line about four-sevenths length of disk; anterior ear somewhat produced, subarcuate laterally and sculptured by about 5 prominent radial ridges and numerous fine imbricating incremental lines; posterior ear about three-fourths length of anterior, sculptured similarly, but slightl} less prominently, and rectangularly truncated. Left valve similar to right, except that the ribs are narrower, and the interspaces broader; ears similar to posterior one of right valve. Hinge with a deep resilial pit, on each side of which are several prominent lateral crura or teth.

Dtinensionft.—AM. 140 mm.; long. 188 mm.; hinge line 85 mm.; diameter 50 mm.; umbonal angle 105.

The tops of the ribs sometimes overhang the interspaces and also sometimes appear smooth. Great variation is shown in regard to the number, abruptness, and prominence of the constrictions on the disk. One or two are generally present near the umbo in most specimens, and some show as as six or seven at different periods of growth. The specimens of this species from Orange County are generally freer from constrictions and the disks are usually' more compressed than in the forms from central California; otherwise the former are normal types.

P, crmHlcardo is characterized by its comparatively few ribs, which, with the interspaces, are more or less prominently striated. It is distinguishable from P. aMeyi by its relatively greater length, fewer ribs, and tendency to be constricted at different stages of growth; distinguishable from P, magnolia with which it is often confused, by its more numerous and much narrower ribs, relatively shorter hinge line, more prominently striate (!ars, and its tendency to become constricted; distinguishable from P. eatrellanm with which it is often associated, by its fewer and rather finely striate ribs and lack of a major intercalary riblet (the bottoms of the inteispaces of craicarcbj being striate rather than containing a riblet). Some of the lateral ribs and interspaces, and the surface near the periphery}' of the disk in adult* of P. estrellanns generally show sculpture similar to that characteristic of P, crasHicardo,

P. crassicardo is found abundantly in the San Pablo, or upper Miocene formation of central California, and also in beds of possibly lower Miocene age in southern California.

Miocene Pectens. 73

Mr. Homer Hamlin and the writer found P. crassicardo associated with the following fauna in beds of somewhat uncertain age, in a small ravine one-lialf mile south of J. C. Griffin's ranch house, Priest Valley, Monterey Count}; P, disco Conrad, Aijasoma {aff,) harlerlaiiartt Cooper, Myt!lut< {((Jf\) matheirsoni ! Gabb, Verttis perteiiuiH Gabb, and (Xstna titan Conrad.

In the Valcito Valley, Fresno County, Mr. H. W. Turner found P. crassicardo with YentiS jtertertuis Doslnla and Tell In a sp.

Mr. Eldridge found P, craKslcardo associated with the following species in beds of probable lower Aliocene age on the ridge between the Upper and Lower Ojai valleys, Ventura County: TurrUelUi {cf,) hoffmamii Phacoldes sp. (flat), Ostreas, Nassa sp., DeiitaUinn sp., Cftione Leda sp. Balamis sp., and Tritonium or Ffisus sp.

Dr. Stephen Bowers has found P, cvdHHlcardo with the following species in the Miocene of Laguna Canyon, San Joaquin Hills, Orange Count}': Pecten tstrellaniis Glycymerls ? sp., Turritellu hoifmann! Chtonc n. sp. (large, coarse sculpture), AgasmiiakerntaRuiu and Gyrodes % sp.

A beautiful specimen of P, crumlcardo in the National Museum (No. 154154) labeled from '' California '' is associated in the matrix with Saxido7nus gracilis Tresus nuttalli and Litmuna rentondi. As the last mentioned species is found only at Kirker Pass it is safe to assume that this magnificent specimen (which is figured) is from that locality.

The type of P, crassicardo (PI. XVHI, tig. 1), which is now in the collection of the Philadelphia Academy of Natural Sciences, is simply labeled "California. Pres. by Dr. Wilson.'

Range.

Miocene (upper). San Pablo Bay, Contra Csta County (Merriam, Arnold, and others); Kirker Pass, Contra Costa County (U. S. N. M.); Mount Diablo, Contra Costa County (Pioche collection, Univ. Cal.); Scott Valley, Santa Cruz County (Miss L. J. F. Hecox); Cammatta ranch and San Juan Valley, east of San Luis Obispo, San Luis Obispo County (Fairbanks, Moran, Arnold); Priest Valley, Monterey County (Hamlin, Arnold); San Ardo, Monterey County (Fairbanks, Hamlin, Anderson, W. C. Dudlc} for Cal. St. Min. Bureau, Arnold); Quail water Creek, San Luis Obispo County (Anderson); Ventura County (No. 12772, C. S. M. B.); Sunset district, Kern County (Eldridge); Valcito Valle}', Fresno County (Turner).

Miocene (middle or lower). Devils Den, Kern County; Ojai Valle}', Ventura County (Eldridge); ? El Toro and Laguna Canyon, Orange County (Bowers, Arnold).

Pecten (Lyro pecten) Crassk arix) Conrad var. hamiltoni n. var.

PI. XI, fijrs. 5 ami (i.

Description, — Adult shell aveniging about 60 millimeters in altitude, subequivalve, equilateral, convex; sides concave above; margins smooth. Right valve with 15 to 17 prominent convex-topped ribs, separated bv interspaces narrower

72 Tertiary And Quaternary Pectens Of California.

1894. Pedn eslrellanus Conrad, Cooper, Bull. Cal. St. Min. Bureau, No. 4, pt. 5, 18d4, p. 67 (in part). 1898. Pecten magnolia Dall, Trans. Wagner Free Inst. iSci., vol. 3, pt. 4, p. 702 (in part); not Pecten

magnolia Conrad, Pac. R. R. Rept, vol. 7, 1857, p. 191, pi. l,.fig. 2. 1901. Peden magnolia Dall, Nautilus, vol. 14, 1901, p. 117 (in not P. magnolia Conrad, 1857. 1904. Pecten (Lyropeden) diahloensis Arnold, MS. (a distorted specimen of P. cransicarfh being the

type).

Descnptum. — Adult, shell averaging about 130 millimeters in altitude, about as long as high, inequivalve, convex, equilateral (except for ears), thick, and generally prominently and abruptly constricted or undulated one or more times near the umbo and sometimes at later stages of growth; sides nearly straight; base regularly rounded; margins smooth. Right valve with 14 to 17 prominent, perpendicularsided, convex-topped ribs, which are separated by more or less deeply channeled, flat- topped, convex-bottomed interspaces somewhat narrower than the ribs; whole surface of ribs and interspaces sculptured by numerous radial nitrite and fine, minutely wavy, imbricating, concentric lines; hinge line about four-sevenths length of disk; anterior ear somewhat produced, subarcuate laterally and sculptured by about 5 prominent radial ridges and numerous fine imbricating incremental lines; posterior ear about three-fourths length of anterior, sculptured similarly, but slightly less prominently, and rectangularly truncated. Left valve similar to right, except that the ribs are narrower, and the interspaces correspondingly broader; ears similar to posterior one of right valve. Hinge with a deep resilial pit, on each side of which are several prominent lateral crura or teeth.

Di/nefisimis.—Alt 140 mm.; long. 188 mm.; hinge line 85 mm.; diameter 50 mm. ; umbonal angle 105.

The tops of the ribs sometimes overhang the interspaces and also sometimes appear smooth. Great variation is shown in regard to the number, abruptness, and prominence of the constrictions on the disk. One or two are generally present near the umbo in most specimens, and some show as man}' as six or seven at different periods of growth. The specimens of this species from Orange County are generally freer from constrictions and the disks are usually more compressed than in the forms from central California; otherwise the former are normal types.

P. crassleardo is characterized by its comparatively few ribs, which, with the interspaces, are more or less prominently striated. It is distinguishable from P. aMey'i by its relatively much greater length, fewer ribs, and tendency to be constricted at different stages of growth; distinguishable from P. mgnoUa with which it is often confused, by its more numerous and much narrower ribs, relatively shorter hinge line, more prominently striate rs, and its tendency to become constricted; distinguisliable from P. tHtrellanm with which it is often associated, by its fewer and rather finely striate ribs and lack of a major intercalary riblet (the bottoms of the interapaces of P, cramlcardo being striate rather than containing a riblet). Some of the latei'al ribs and interspaces, and the surface near the periphery} of the disk in adults of P. estreUamiH generally show sculpture similar to that characteristic of P, cviissicardo,

P, crassicardo is found abundantly in the San Pablo, or upper Miocene formation of central California, and also in beds of possibly lower Miocene age in southern California.

Miocene Pectens. 73

Mr. Homer Hamlin and the writer found cruHslcardo associated with the following fauna in beds of somewhat uncertain age, in a small ravine one-half mile south of J. C. Griffin's ranch house, Priest Valle}, Alontere}' County; P, dlscujn Conrad, Agamma {aff,) harlerianunt Cooper, My t Huh {(ijf\) iitatheicsonll (jabb, Veriiis pertenuis Gabb, and (Mtrea titan Conrad.

In the Valcito Valley, Fresno County, Mr. H. W. Turner found P. cranmardo with VentiS Doslnla (rf.) jjouderoa and Tellina sp.

Mr. Eldridge found P, crass/'cardo associated with the following species in beds of probable lower Miocene age on the ridge between the Upper and Lower Ojai valleys, Ventura County: Pecten loinpocerhns Turrltella (cf.) hoffriianni„ Phacmdes sp. (flat), (htrea. NaHna sp., DcntaUum sp., Chionr Zeda sp, litdmnis sp., and Tritoiiluin or Fuhu sp.

Dr. Stephen Rowers has found P, with the following series in the Miocene of Laguna Canyon, San Joaquin Hills, Orange County: Pecten estrellanus Glycymeriif ? sp., Tunitella hoffihunni Chione n. sp. (large, coarse sculpture), Agasoinakhmlaniun and ? sp.

A beautiful specimen of P, crasHlairdo in the National Museum (No. 154154) labeled from "" California " is associated in the matrix with Saxidoinus gracilis Tresus nuttalll and LtUrrtna remand!. As the last mentioned species is found only at Kirker Pass it is safe to assume that this magnificent specimen (which is figured) is from that locality.

The type of P. crasslcardo (PI. XVUI, tig. 1), which is now in the collection of the Philadelphia Academy of Natural Sciences, is simply labeled "California. Pres. by Dr. Wilson.''

Miocene (upper). San Pablo Bay, Contra Costji County (Merriam, Arnold, and others); Kirker Pass, Contra Costa County (U. S. N. M.); Mount Diablo, Contra Costa County (Pioche collection, Univ. Cal.); Scott Valley, Santa Cruz County (Miss L. T. F. Hecox); Cammatta ranch and San Juan Valley, east of San Luis Obispo, San Luis Obispo Count} (Fairbanks, Moran, Arnold); Priest Valley, Monterey County (Hamlin, Arnold); San Ardo, Montere}' County (Fairbanks, Hamlin, Anderson, W. C. Dudley for Cal. St. Min. Bureau, Arnold); Quail water Creek, San Luis Obispo County (Anderson); Ventura County (No. 12772, C. S. M. B.); Sunset district, Kern County (Eldridge); Valcito Valley, Fresno County (Turner).

Miocene (middle or lower). Devils Den, Kern County; Ojai Valley, Ventura County (Eldridge); ? El Toro and Laguna Canyon, Orange County (Bowers, Arnold).

Pecten (Lyropecten) Crassk ardo Conrad var. hamiltoni n. var.

PI. XI, iip. 5 ami H.

Description, — Adult shell averaging about 60 millimeters in altitude, subequivalve, equilateral, convex; sides concave above; margins smooth. Right valve with 15 to 17 prominent convex-topped ribs, separated by interspaces narrower

74 Tertiary And Quaternary Pectens Of California.

than the ribs; surface of ribs and interspaces sculptured by rather coarse radiating lines and imbricating incremental lamellae; anterior ear longer than the posterior, and with 4 prominent, finely imbricated radials; byssal notch rather deep; posterior ear rectangularly truncated, and with radial and concentric sculpture. Left valve similar to right, except with slightly wider interspaces. The disk of this variety is generally contracted after reaching an altitude of 40 millimeters or more.

Dimenmmis. — Alt. 40 mm.; long. 47 mm.; hinge line about 30 mm.; diameter about 14 mm.

This variety is closely allied to the typical P, crash4ardo and probably is the ancestral form. It is distinguishable from the latter by its smaller size when adult, narrower, lower, and more strongly and evenly convex-topped ribs, narrower anterior ear on the right valve, and tendency to become more contracted, and consequently more convex when adult or at an altitude of about 60 millimeters. P. var. hamiltmii resembles P, estrelliinus in size and shape, and in the earlier stages of growth is almost indistinguishable on account of having but a single line down the middle of the interspace, which the intercalary riblet of P. estrellmus. After attaining an altitude of about 30 millimeters the two species are easily separated, as at that stage of growth the radial striation becomes apparent on the ribs of P, var. havulton! and the radial line in the interspace is supplemented by others, thus ornamenting the interspace with several radial lines rather than with an intercalary riblet, as in P. estnl- Uinus, The tendency to undulations caused by temporary contractions in the growth of the disk near the umbo is often exhibited to a slight degree in some specimens of P, var. hainiltoni.

This variety is known only from the Mount Hamilton Range, where it is quite common from a few miles south of Mount Hamilton to Mount Diablo, in Contra Costa County. P. var. hamlltonl occurs in the horizon of the Miocene which is so well developed in the vicinity of Alum Rock Canyon, Santa Clara County. The type is from this locality, and is now in the U. S. National Museum (No. 164845). Named in honor of Mr. W. R. Hamilton, of Bodie, Cal.

Miocene (upper). Alum Rock Canyon, Santa Clara (>>unty (Turner; J. P. Smith; Arnold); Mount Hamilton, Santa Clara County (Crawford); Mount Hamilton Range in Alameda County (Yates).

Pecten (Lyropecten) estrellanus Conmd.

PI. XIX, figs. 1 and la; PI. XX, figs. 1, 2, and 2a; PI. XXI, figs. 1, la, 16, 2, 2a, and 26.

1856. Pallium estrellanum Conrad, Pac. R. R. Rept., vol. 6, pt. 2, 1856, p. 71, pi. 3, tig. 15.

1856. Pallium estrellanum Conrad, Pac. R. R. Rept., vol. 7, pt. 2, 1856, p. 191, pi. 3, figs. 3 and 4.

1857. Pallium estrellanum Conrad, Proc. Acad. Nat. Sci. Phila., vol. 8 for 1856, p. 313. 1863. Lyropecten estrellanus Conrad, Proc. Acad. Nat. iSci. Phila., vol. 6 for 1862, p. 291. 1863. Lyropecten rolceformis Conrad, Proc. Acad. Nat. Sci. Phila., vol. 6 for 1862, p. 291. 1869. Liropecten estrallanus Conrad, Gabb, Pal. Cal., vol. 2, 1869, p. 105.

Miocene Pecten8. 75

1888. Liropecten estrellantis Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 246.

1894. Liropecten estrellanus Conrad, Cooper, Bull. Cal. St. Min. Bureau, No. 4, pt. 5, 1894, p. 57, pi. 5.

figs. 65-67 (text only in part). 1898. Pecteji {Lyropecten) Heermmmi Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 701

(not P. fhermanni Conrad, Proc. Acad. Nat. Sci. Phila., vol. 7, 1855, p. 267, which is P,

cauriiius Gould).

Descriptkm. — Shell averaging about 90 millimeters in altitude, somewhat longer than high, equivalve, equilateral, of medium thickness, generally quite ventricose, and with margins more or less seriate; base evenly" rounded; sides sloping, slightly concave above. Right valve with 16 to 20 prominent, squarish ribs separated by channeled interspaces which are narrower than the ribs; interspaces each with one shai'ply outlined, scjuarish riblet in the middle; surface sculptured by fine raised incremental lirulie which loop back over the ribs and riblets, and, on the anterior and posterior portions of the disk, by radiating striss, which increase in number as the periphery of the disk is approached; hinge line straight and nearly equal to one-half length of disk; ears equal; anterior ear arcuate in front and ornamented above byssal area by three or four radiating ridges and numerous incremental lines; byssal notch sharply defined; byssal area with incremental sculpture only; posterior ear with slightly concave end and ornamented by 5 or 6 radiating ridges and more or less prominent incremental lines. Left valve with the ribs narrower and having more sloping sides and rounded tops than those of the right; interspaces wider; auxiliary riblets inclined to be dichotomous near the ends in the more mature specimens; the looping incremental lirulffi and the secondary radiating lines apparently more highly developed in this valve than in the right; ears similar to the posterior ear of the right valve.

DimenHlork, — Alt. 93 mm.; long. 105 nmi.; hinge line 50 mm.; diameter 47 mm.

This is a most variable species in size, shape, and sculpture, the above description applying to the most common form. One peculiar characteristic sometimes shown by this species is a contraction or interruption in the growth at different stages. See PL XXI, figs. 1, la, Xh, Up to the first interruption the sculpture is generally simple and quite constant, but afterwards it (especially the radial) becomes more complex, the riblets in the interspaces becoming dichotomous and the radiating lines becoming more numerous and prominent.

The variety of this species described as Lyroptcten volijefornils by Conrad is the extremel}' convex type. Conrad thought that the valves were unequal in the very convex shell, but in all the specimens of this sort examined by the writer, both valves show an equal amount of convexity. This very ventricose form is common near Coalinga, Fresno County, in beds of probable San Pablo (upper Miocene) age.

Specimens of this species from Catalina Island show more ribs (right valves, 19 to 21) than the average, and also appear to be slightly inequi valve, the left valve being the more ventricose. The characteristic interruption and constriction took place on most of the Catalina specimens at an altitude of about 55 millimeters.

A specimen of this species from San Benito County, collected by Mr. H. W. Turner, is very convex, and shows beautiful equal, equidistant, looped lamellaB over the surface of the valve. The intercalary riblets on this specimen are sharply defined.

76 Tertiary And Quaternary Pecten8 Of California.

Between San Lucas and San Ardo, Monterey County, Mr. Homer Hamlin found a specimen of P, estrelkintui measuring 125 niillimeters in altitude, whicli sliows the striations well developed on the anterior and posterior ribs and near the ends of the middle ribs and interspaces. The flat forms grading into var. cataZinse were found associated at this locality with the typical convex shells.

In central California, especially in the region about the Salinas Valley, the P. estrellurms associated with the large Ostrea titan Conrad usually have nineteen ribs, while those found in the horizon of Ostrea palmula Carpenter and Chertui helcheri Hinds average two or three less. The latter horizon appears to be above that of O, titan.

In the region around Coalinga, Fresno County, P, estrellanita is very common, and is usually associated with Tainiosorna gregaria Ostrea titan,, Veyivs pertenuis CMcm n. sp. (large; coarse sculpture), Area eanali etc., in beds which may be the equivalent of the San Pablo formation. The significance of the total absence of P. eMrellunm from the type locality of the San Pablo is not at present known.

So far as is definitely known, this species is confined to the Miocene, where it is found in nearly every county of California from Napa to Orange. In some places it is found associated with a characteristic lower Miocene fauna, while at others the same form will be found in the San Pablo or upper Miocene.

Bange.

Miocene. Napa County (Lockwood); Solano County (Cooper); Alameda County (Yates); Mount Hamilton Range (J. P. Smith; Arnold); Santa Cruz Mountains (Ashley; Arnold); San Lucas and San Ardo, Monterey County (Anderson; Hamlin); Lynch's Mountain, Monterey County (C. S. Smith); 15 miles northeast of San Miguel, Monterey County (Hamlin; Arnold); San. Luis Obispo and Santa Barbara counties (Conrad; Fairbanks; R. Moran; J. H. Wilson; Arnold, and others); Coalinga, Fresno County (Watts; Eldridge; L. D. O'Neal); San Benito County (Turner); Santa Ana Range, Orange County (Watts); El Toro, Orange County (Bowers). .

Pecten (Lyropecten) estrellanus Conmd var. catalin n. var.

PL XX, figs. 3, 3a, and 4.

Description. — Shell averaging about 65 millimeters in altitude, considerably longer than high, equivalve, equilateral, of medium thickness, only slightly ventricose, and with margins more or less serrate; base evenly rounded; sides only slightly concave above. Right valve with 19 or 20 square, flat-topped ribs, all of which are sculptured by incremental lines and the 3 or 4 outer ribs on each side by more oi* less prominent radial lines; intei'spaces narrower than ribs and ornamented by a prominent squarish riblet; hinge line over one-half length of disk; anterior ear arcuate in front, with rather small byssal notch, and ornamented by concentric lines and 5 or 6 i-ather prominent radiating ridges; posterior ear with concave end and ornamented by numerous fine radiating ridges and incremental lines. Left valve similar to right except that the ears are both like the posterior one of the right valve, and the interspaces are relatively a little wider.

78 Tertiary And Quaternary Pecten8 Of California.

Description. — Shell averaging about 150 millimeters in altitude, slightly longer than high, subequivalve, equilateral, rather thick, somewhat ventricose, and with smooth margins; base regularly rounded; sides sloping above, and slightly concave. Right valve slightly more convex than left, with about 9 to 11 broad, flat-topped, equal, equidistant ribs; interspaces slightly narrower than ribs and flat-bottomed; whole surface of ribs and interspaces covered by imbricated radiating riblets (about 10 on each rib) and fine, concentric incremental lines; hinge line about two-thirds the length of the disk; anterior ear slightly longer than the posterior, with arcuate end and fine concentric incremental sculpture, but obsolete radiating ridges; posterior ear with no radial sculpture whatever; b3ssal notch relatively small. Left valve quite similar to right but with narrower, more rounded ribs; sculpture of radiating riblets and fine wavy incremental lines; interspaces broader than in right valve; ears almost identical to those of right.

Dimensions. — Alt. 146 mm.; long. 150 mm.; hinge line 105 mm.; diameter 65 mm.

The original description and figure of this species are poor, but there is no question in the writer's mind as to which species Conrad applied this name. There is no other large Pecteii in the Miocene of the West Coast having the small number and characteristically large, striate ribs, and ears with so little radiate sculpture. The figure of the type, poor as it is, shows that there was little or no radiate sculpture on the ears of the specimen or specimens serving as the type for the drawings. Furthermore, there is no other Pecten, except the species above described, which would bring out the following comment, which Conrad, in his original description, applied to P, magnolia:

'This species will compare in size with P, Jefferso7iius Say, and is so remarkably similar to it that it may prove to be the same* species when more perfect specimens are collected."

The specimens which served a.s the types for Conrad's P, magnolia are in the U. S. National Museum (Nos. 13311 and 18325), and came from the Santa Inez Mountains, Santa Barbam County. Although broken, these specimens show the ribbing and sculpture of the original shell almost perfectly.

In many of the worn specimens of this specie the radiating striaj have been lost, and the ribs appear smooth. Internal casts show smooth rounded ribs for both valves. The distinguishing characteristics of this magnificent species, some of which attain an altitude of over 210 millimeters, are its size, small number and equality of ribs, equality of ears, and almost total lack of any radiating sculpture on the ears.

P. magnolia is somewhat closely allied to P, orasslcardo and is no doubt its precursor. It is distinguishable from the latter by its fewer (9 to 11, instead of 14 to 17), broader, more square-cut and more coarsely radially sculptured ribs, and the obsolete radial sculpture on its ears.

P. m/ognolia is one of the most characteristic of the lower Miocene, or Vaqueros formation, fossils. In the region around Mindego Hill, San Mateo Count} it is found in the Vaqueros sandstone associated with the following fauna: Agasoma harJcerlanum Agasoma (cf,) gravida Agasoma Area (cf.) miorodontay

Miocene Pectens. 79

Balanus (cf.) estrellamiA Cardium (Trachycardium) n. sp., Chions mathewsonli Chione n. sp. (large; coarse sculpture), princeps Chuna biplicata Dosinia oonradi Dofdnia matheficsfmii DoHlnia (cf.) rnmitanu Dosinla {ajf,) ponder'osa Galeru8 {aff.) eccentricics Olycytneris n. sp. (large), Phacoides acutilineatus Phawides richthofeni Mytilus viatheiosonii Never ita reclmiana Ostrea {aff,) titan Panopea genera Pecten estreUambs Pecten {Plugioctenium) andenimu Sol en sicarms Tivela inezianay Trochita costdlata,, TurriteUa hjoffmanni. On the south fork of the lower Ojai Valley, Ventura County, Mr. Eldridge found P, magnolia associated with Chione n. sp. (large; coarse sculpture), Mytilus matheicsonii Turritella hoffmanni,, Pecten sespeensis var. hydel and other lower Miocene forms.

Miocene (lower). Mindego Creek, 10 miles south of Stanford University (Arnold); Corral de Piedra Creek, San Luis Obispo County (J. H. Wilson; Robert Moran; Fairbanks); Hazard Canyon, VI miles southwest of San Luis Obispo (N. H. Drake); Morro and Toro creeks, San Luis Obispo County (Fairbanks; R. Moran); Santa Inez Mountains, Santa Barbara County (Conrad); near Oceanic quicksilver San Simeon, San Luis Obispo County (L. Wagner); Ojai Valley, Ventura County (Eldridge).

Pecten (Lykopecten) miguelensis n. sp.

PI. XXII, figf. 1, la, and l/>; PI. XXIII, fig. 1.

1898. Pectni Lifrojecten) Heermnnni Dall, (not Conrad) , Trans. Wagner Free Inst. Sci., vol. 3, pi. 4, p. 701. (Specimens in U. S. Nat. Mus., No. 6:97, P. Ileermanni bv Conrad; Pi. XXIII,

Descrlpthn, — Shell averaging about 110 millimeters in altitude, about as long as high, inequivalve, subequilateral, rather thin, and with margins more or less sermte; base rounded; sides slightly concave above, the posterior being slightly longer than the anterior. Right valve more convex than the left, with 17 or 18 prominent rounded ribs, each sculptured })y several (10 or 11 at extremity of ribs in type) distinct radiating raised riblets and numerous sharp, minutely wavy, incremental lines; interspaces narrower than ribs, and containing by a prominent radial auxiliary rib,* which is ornamented by the incrementjil sculpture, and toward the periphery of the disk, by two or more radiating riblets as in the large ribs; hinge line somewhat longer than one-half the length of the disk; anterior ear arcuate in front, with small byssal notch, and sculptured by 5 or 6 prominent, rounded, radiating ridges and numerous sharp, concentric lines; posterior ear with 10 or 11 radiating riblets and fine incremental sculpture. Left valve less ventricose than the right, but otherwise similar to it, except that the ribs are slightly narrower and the interspaces relatively broader; ears similar to those of the right valve except that the anterior one lacks the byssal notch.

Dimensions, — Alt. 107 mm. ; long. 110 mm. ; hinge line 60 mm. ; diameter 50 mm.

This species is distinguishable from estrellanus and others of the same group by its larger size, inequality of valves (which are more or less inequilateral), and radially striate surface from umbo to periphery. It sometimes shows the constric-

80 Tertiary And Quaternary Pectens Of California.

tions common to P. estrellanvs, miguel7iiH may be the P, catilliformis of Conrad (Pac. R. R. Rept., Vol. V, Pt. II, p. 83, PL IX, fig. 83, 1857), but his description is so brief and his figure so poor that it is impossible to make anything definite out of it.

P, mlgudensw is confined to the Miocene (probably lower horizon).

The t3pe is a slightly crushed specimen from San Miguel Island. It is the specimen figured, and is now in the collection of the University of California.

Miocene. San Miguel Island (Univ. of Cal.); Santa Rosa Island (No. 12333, Cal. St. Min. Bureau); Santa Inez Valle} near Santa Barbara (J. H. Wilson); Santa Inez Mountains, near Santa Barbara, Santa Barbara County (Pac. R. R. Expedition).

Pecten (Lyropecten) perrini n. sp.

PL XIV, figs. 1 and la; PI. XV, fig. 1.

Description, — Shell averaging about 150 millimeters in altitude, somewhat longer than high, inequivalve, equilateral, of medium thickness, ventricose, and with smooth margins; base regularly rounded; sides sloping and decidedly concave above. Right valve nearly flat, with about 23 unequal, narrow, more or less rounded, and often prominently imbricated, radiating ribs, which are sometimes dichotomous; intei'spaces unequal, narrow, and occasional!} ornamented by a small| auxiliary riblet; surface sculptured by fine incremental lamellae which are much more prominent in sonie specimens than in others; hinge line about one-half length of disk; ears about equal in length; anterior ear wide, ornamented by concentric incremental sculpture; byssal notch wide and deep; posterior ear ornamented by several prominent, more or less imbricated i-radiating ridges, and concentric sculpture. Left valve quite prominently ventricose, otherwise similar to the right, except that the ribs seem to vary even more in relative size and spacing; anterior ear lacking notch, otherwise ears similar to those of the right valve.

Diifie7islo7iH, — Alt. 150 mm.; long, (restored) 160 mm.; hinge line (restored) 80 mm.; diameter 55 mm.

This is a most variable species, there being no two specimens sculptured in exact the same manner in a series of over fifty specimens examined. The convexity of the valves is almost constant, the variable factors being the number and relative importance of the intercalary ribs, and the prominence of the incremental sculpture.

The geologic range of P. perrini is the lower to the middle (?) Miocene. It is found associated with Pecten magnolia,, and other characteristic lower Miocene fossils between Morro and Toro creeks, San Luis Obispo County, while at Roblar, in the same county, it is found with P. discus a species found usually in the Santa Margarita formation.

The type, an imperfect specimen, of which both valves are figured, is from the lower Miocene between Morro and Toro creeks, San Luis Obispo County,

Miocene Pec5Ten8. 81

and is now in the collection of the department of geology, Stanford University. Named in honor of Dr. James Perrin Smith, professor of paleontology at the Leland Stanford Junior University.

Miocene (middle?). Roblar, 12 miles from Paso Robles, and on ranch of W. F. Gillis, 10 miles southwest of Paso Robles, San Luis Obispo County (J. P. Smith).

Miocene (lower). Between Morro and Toro creeks, and on the Lenton ranch, between Morro and Old creeks, San Luis Obispo County (Fairbanks, R. Moran); 30 miles north of Santa Monica and 1 mile from the ocean, Ventura(?) County (R. E. Maynard); Pyramid Mountain, Greenhorn Mountains, Kern County (No. 12925, C. S. M. B.) (Watts).

Pecten (Lyropecten) vaikjiiani n. sp. PI. XXIII, figs. 3, 3, and 3/>.

Descriptum. — Shell averaging alwut 40 millimeters in altitude, slightly longer than high, inequi valve, equilateml, convex, and showing constrictions with consequent undulations on the right valve and nodose ribs on the left; base regularly rounded; sides nearlv stmight above; margins smooth. Right valve with 12 prominent convex ribs separated by concave-bottomed interspaces somewhat narrower than the ribs; surface of ribs and interspaces sculptured by numerous fine, imbricated, thread-like, radial lines, between which are fine imbricating concentric lira, the lines multiplying by intercalation toward the periphery of ' the disk; hinge line about five-eighths length of disk; ears unequal, the anterior much elongated, rather narrow, and ornamented by 4 very prominent, rounded, sharply imbricated radials and numerous fine imbricating incremental lirae; byssal notch deep; posterior ear about one-half length of ante'ior, somewhat concave behind, and ornamented by about radial and numerous fine incremental lira?. Left valve similar to right, but with narrower, sharper ribs and correspondingly broader interspaces; the second, fourth, seventh, tenth, and twelfth ribs from the posterior end are more prominent than the others, and are subnodose at the lines of undulation of the disk; anterior ear similar to that of the right valve but with 2 or 8 more radials, which are less prominent; posterior ear like that of right.

DhnenHiouH, — Alt. 37 mm.; long. 40 mm.; hinge line about 25 mm.; diameter 15 mm.

This beautiful little Pcvtau though allied to P, viagnolia P, crasicardo etc., is distinguishable by its small size, obviously}' unequal ears, long and strongly radially sculptured right anterior ear, deep basal notch, undulating disk, and finely striated, concave-bottomed interspaces. This form seems to combine the number of ribs of P, nuujmtJUi {P, niafjnolia generally has one to three less), with the sculpture of P. craHxlcanlo var. hamiltoni the undulations of P. crasstca/rdo and the long, strongly sculptured, right anterior ear of the typical Chlamys. It appears to be a connecting link between the typical Chlamys and Lyropecten.

17260— No. 47—06 6

82 Tertiary And Quaternary Pecten8 Of California.

The range of this species is not definitely known. It is found in the Miocene, probably lower, of the Ojai Valley, Ventura County. The type, which was collected at the above locality by Dr. Stephen Bowers, is now in the collection of Delos Arnold. The species is named in honor of Dr. T. Wayland Vaughan, of the United States Geological Survey.

Miocene (lower). Ojai Valley, Ventura County (Bowers).

Pecten (Plagioctenium) andkrsoni II. sp.

PI. XXVI, figs. 5, 5a, 6, 7, 8, and 8</.

1894. PecUn discus Cooper (not Conrad), Bull. Cal. St. Min. Bureau, No. 4, pt. 5, 1894, p. 57, pi. 5, figs. 55 and 56 (in part).

Description. — Shell averaging about 35 millimeters in altitude, generally somewhat longer than high, both valves convex, more or less inequivalve and inequilateral; margins smooth; base regularly rounded; sides concave above. Right valve with 14 to 18 prominent rounded ribs, separated by flat-bottomed interspaces, which are generally of about equal width to, but sometimes narrower than, the ribs; surface sculptured by numerous, sharp, imbricating, incremental lines, and sometimes, at irregular intervals, by more or less prominent lines of interrupted growth; hinge line more than one-half length of disk; ears subequal; anterior ear with 3 or 4 sharp radials and numerous fine concentric lines; byssal notch quite pronounced; posterior ear sculptured similarly to anterior, and truncated nearly rectangularly. Left valve more convex than the right, sculptured similarly and with similar ears, except that the notch in the anterior is not so pronounced.

Dimensions. — Alt. 37 mm.; long. 44 mm.; hinge line 23 mm.; diameter 8 mm.; umbonal angle 105°.

A prominent characteristic of this species is that the left is decidedly the more convex of the two valves. In this respect it is similar to P. latiaurttvs and varieties. In fact, the young of P. anderHoni is almost indistinguishable, in some instances, from small specimens of P, var. monothneris. The young of P. andermni are equilateral, are relatively more convex, and have more prominent ribs than the adult forms.

Those specimens of P, andersoni found in the earlier formations appear to be somewhat smaller, and have on an average fewer ribs (14 to 17) than those in the later Miocene horizons, which have from 15 to 18. Exceptions to this rule, however, are not rare, one specimen, for example, from the same locality as the type (which has 16 ribs on the left valve) having 18 ribs.

It would not be surprising to the writer to find, after an examination of a large series of P, andersoni and allied forms from the upper Miocene, that it is more or less closely related to P, discus. Large specimens of P, andersoni very closely resemble some specimens of P, discus but differ from the latter in the fewer number (14 to 18) of their ribs, P, discus having 18 to 21.

Miocene Pectens. 83

inidersoni ranges from the lower to the middle (and probably upper) Miocene. At locality No. 9 (L. 8. J. U. Geol. Survey), on 'Tuff Hill," 3i miles southeast of Stanford University, anderHoni is associated with the following species: Pecten hranneri Chionen, sp., Phrieoidefi acHttlineatus Terthratella (?) n. sp., Glycxjm. sp., and BaJunm sp. {cf.) At locality No. -I:, not far from but stratigraphically considerably above No. 9, we find P, with the the following: Agmovia hare7*!anum Area microdimta Chkme sp., CaJUsta n. sp. A., DosmUi mathetmonii Leda (cf,) taphria Phacoides acutlllneatiiii Mactra cidifomica Katica ocoijima (?), Saldomns gibhomcs Tapes trtnwata (i) Trochlta costellata Tdllna {Anguluji) sp., TrUonium sp., Tlvela hiezlana and Yoldia n. sp. {aff,) cooperL On the Searsville road, miles west of Stanford University (locality 2), P, is associated with the following among other species: Agasonta grairlda Agasfnna kerniajinm Dosinia {aff.) ponderosa., and Pinna aJmnedensis. At Barker's ranch, Kern County, Mr. Watts found P. anderHfmi associated with barker ianum and Jcemuinnm and other supposedly characteristic lower Miocene forms. P, andersoni occurs with P, crasslcardo in the upper Miocene 8 miles south of Mount Diablo. In Avenal Canyon, Kern County, P, andersoni is associated with P, andersoni var. harkerianus ocoyana. Venus sp., Ostrea sp., and a large flat Dosinia, In the Devils Den country, Kern County, P. andersoni is found with P, crassicardo in beds of probable lower Miocene (Vaqueros) age.

The type of P. aiulersoni,, which is now in the collection of the department of geology, Stanford University, is from locality 127, three-fourths mile below Zayante station on Zayante Creek, Santa Cruz County, where it was found associated with P. sespeensis var. hydei and Balanns estrellanu'<. The beds from which the type was taken lie only a few feet below, and conformable with, the base of the chamcteristic Monterey shales, which are very well developed in the vicinity.

Miocene (upper). Three miles south of Mount Diablo, Contra Costa County (University of California); Pacheco, Contra Costa Count\ (J. P. Smith); San Pablo Bay, near Pinole, Contra Costa County (Merriam, Arnold).

Miocene (middle and lower). Locality 127, Zayante Creek, three-fourths mile below Zayante station; near (Henwood (Miss Hecox); near Magnetic Springs; near Felton (locality 82), Santa Cruz County; near Stanford University, at localities 1, 2, 3, 4, 9, 3-1:, and 85, Santa Clam and San Mateo counties (Branner, J. P. Smith, Arnold, and others); Barker ranch, Kern Count}" (Watts); New Almaden (Turner); Contra Costa County (Lawson); near head of Slacks Canyon, NE. i sec. 9, T. 22 S., K. 18 E., Mount Diablo meridian, Monterey County (Hamlin); Avenal Canyon, Kern County (Eld ridge); Devils Den, Kern County (Eldridge).

Pectkn (Plaoioctexium) andersoni var. barkerianus n. var.

PI. XXVI. fig. y.

Description. — Shell averaging about 40 millimeters in altitude, somewhat longer than high, equilateral, somewhat ventricose, and with serrate margins; base regu-

84 Tertiary And Quaternary Pecten8 Of California.

larly rounded; sides nearly straight, sloping at a moderately low angle. Left valve with 17 rather narrow, prominent rounded ribs, eiich with a rounded, thread-like riblet running longitudinally along its top; at more or less regular intervals small obsolete spines protrude from the riblet; interspaces wider than the ribs, with sloping sides, and flat bottoms; whole surface of disk crossed by very fine incremental lines; hinge line longer than one-half length of disk; ears subequal, rectangularly truncated, and sculptured radiating ridges and incremental lines.

Dhnefisions. — Alt. 40 mm.; long. 44 mm.; hinge line 28 mm.; diameter 7 mm.

This variety, which is characterized by the thread-like riblet along the top of each primary rib on the left valve, has been found only in beds of lower Miocene age {Turritdla ocoyana zone) in the southern San Joaquin country. It is found associated with the following characteristic fauna in the bluffs of the Kern River, 1 mile below the power-development station, Kern County: Conits n. sp., Mactra near planulata Phacoide sp., Tellina near idie, TrochiUx film Agasoimi Tcenviavum Agasorna harkerianuin., Leda taphria Leda (off*) foasa Cajicellarm u, sp., Plvrotoina {DoUchotoma) n. sp., Phurotorna (Leucof/7*inir) near jjedroaiia Chmne n. sp. near (jnidki Dentalium 2 n. sp., Nassa (of,) per pinguid Pleurotonia sp., Neptunea n. sp., Crucihulum n. sp., TunritellAi ocoyana Canceller hi {cf.) vetusta Phaeoides (cf,) nuttalli Natica or Lunatla sp., Terehra sp. (probably new), Trophon (cf.) ponderoinn Drillia (<iff*) tf/rosa Solen sicarin. At A venal Canyon, Kern County, Mr. Eldridge found P, var. harkerlanua with P, anderscmi Tnrritella ocoyana Dodnia (large and flat), Vemis sp., and Ostrea sp.

The type of P, var. harkirlamis was found east of the Barker ranch house, near Kern River, Kern County, and is now in the collection of the California Academy of Sciences.

Range.

Miocene (lower). Barker ranch, Kern County (Watts): Avenal Canyon and bluffs of Kern River near power-development station, Kern County (Eldridge).

Pectkn (Plagiootexium) (errosensis gabb var.? mendenhalli n. var.

PI. XXV, tigs. 2, 2a, and 26.

DescrljJtit/n, — Shell, when adult, averaging about 75 millimeters in altitude. Similar to P. verronenjis in shape, convexity, and ribbing, but differing from the latter in much smaller when adult, having fewer ribs (about 19 in the former, while the latter has usually 21 or more), much less prominent incremental lines, and a relatively longer hinge line.

Dlnienmons (of a medium-Hized specimen), — Alt. 48 mm.; long. 44 mm.; hinge line '28 mm.; diameter 17 mm.

Although this form is closely allied to P, eerroHemaU it, nevertheless, should possibly have specific rank, as the differences between it and the typical P. cerroseimis are constant, and it belongs to a different geologic horizon. Not enough is known about its range and relations, however, to warrant a wider separation, at present, than that of a variety.

The type is from beds of probable Miocene age (the equivalent of the Carrizo Creek beds) at Santa Rosalia, Lower California, directly west of and across the Gulf

o

Miocene Pectens. 85

of California from Guaymas, Mexico. At the type locality it is associated with the following fauna: Pecten carrizoenHlH Pec.ten, keep'i Cardium sp., Chirme n. sp., GlycymeriH sp., Otifrea sp. (large), CodaMa sp. (ver\ large), Seimh' {(iff.) pulchra' Cardlta {Cardltamerd) sp., Stronihtm sp., Maha (aff.) rhif/t/i-s echinoid spines, etc. The type of P. var. uneiidenhalli is U. S. N. M. No. 14849, and is from Santa Rosalia, Lower California, where it was collected by Doctor Merrill. Named in honor of Mr. Walter C. Mendenhall, of the United States Geological Survey.

Miocene. Santa Rosalia, Lower California (G. P. Merrill; E. Palmer); head of Garnet Canyon, about 12 miles north of the Mexican })oundary, and Alverson Canyon, about 8 miles north of the Mexican boundary, San Diego County (W. C. Mendenhall: S. Bowers).

Pecten (Plagioctemum) deserti Conrad. PI. XXVI, figs. 1, 2, 2n, 8, 4, and An.

1855. Pecten deserti Conrad, Desc. Foj. and ShelL., House Doc, 129, July, 1855, p. 15 {Me Dall).

1856. Pecten deserti Conrad, Pac. R. R. Rept., vol. 5, 1856, p. 325, pi. 5, fig. 41.

1888. Pecten deserti Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., for 1887, p. 257. 1894. Pecten (Plagioctenlum) deserti Conraii, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 703.

Descrlptl/nt, — Shell averaging about 32 millimeters in altitude, about as long as high, biconvex, and with seri*ate margins; sides straight and sloping at a steep angle. Right valve with 22 or 23 high, narrow, close-set, smooth, rounded ribs, which sometimes show looped incremental lines on their tops near extremities; interspaces deep, narrow, slightly concave bottomed, and ornamented on the bottom by numerous fine, sharp, straight, incremental lines; hinge line about three-fourths length of disk; ears subequal; the anterior slightly convex and ornamented by 4 radiating ridges and numerous incremental lines, while the posterior is ornamented by 6 or 7 radials and numerous concentric lines; b\'ssal notch rather small. Left valve similar to the right, except possibly that the ribs are relatively slightly taller. Hinge strong, with a deep resilial pit and a submarginal channel parallel with the upper margin; numerous parallel microscopic lines perpendicular to the hinge line visible in the crural grooves.

— Alt. 32 mm.; long. 33mm.; hinge line 25 mm.; diameter 17 mm.

This species is distinguishable from allied forms b\' its strong hinge, tall, narrow, close-set ridges and straight incremental sculpture in the bottoms of the interspaces.

P. denevtl has so far been found in beds supposed to be of Miocene age, in the Carrizo Creek district, Colorado Desert, San Diego Count3\ From the evidence at hand it seems likely that P. ( occupies a somewhat different horizon (possibly lower) than that containing P, carrizoaisiH P, keep and P, cerrosensis var. viendenJialli,

Range.

Miocene. East end of Carrizo Mountain, and Ulsa oil well, north of the Mexican boundary, San Diego County (Conrad; Fairbanks; Bowers; Mendenhall).

86 Tertiary And Quaternary Pecten8 Of California.

Pecten (Plagioctenium) discus Conrad.

PI. XXVII, tigs. 1, 2, 3, and 4.

1857. Pecten discus Conrad Pac. R. R. Rept., vol. 7, pt. 2, 1857, p. 190, pi. 3, fig. 1.

1869. Pecteii discus Conrad, (Jabb, Pal. Cab, vol. 2, 1869, p. 122.

1888. Pect£n discus Conrad, Cooper, Seventh Ann. Rept. Cab St. Min., 1888, p. 257.

1888. Pecten pabloeiisis Conrad, Cooper, Seventh Ann. Rept. Cab St. Min., 1888, p. 258 (in part).

1894. Not Pecten discus Cooper, Bull. Cab St. Min. Bureau, No. 4, pt. 5, 1894, p. 67, pi. 5, figs. 55, 56.

( P. andersoni n. sp. )

1898. Pecten (Chlamis?) discus Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898. p. 704.

'iptiim. — Shell averaging about 50 millimeters in altitude, about as long as high, equivalve, equilateral, thin, rather compressed, and with smooth margins; umbonal angle large, averaging about 108; sides somewhat concave above. Right valve with 17 to 20 moderatel} strong, rounded ribs, separated by rather flat interspaces about equal in width to the ribs; surface sculptured by regular, elevated, wavy, incremental lines and, at irregular intervals, generally by more or less prominent lines of interrupted growth; hinge line about one-half length of disk; ears unequal, the anterior showing several strong radials, while on the posterior the radials are obsolete; both ears sculptured by fine concentric lines. Left valve similar to right; ears more or less distinctly radially ridged and obliquely truncated.

Dimensions, — Alt. 48 mm.; long. 50 mm.; hinge line 24 mm.; diameter 8 mm.; umbonal angle 108.

This species, of which the type is a poor specimen, being preserved as a cast in indui-ated cla', is characterized by its moderately strong, convex ribs, compressed disk, and strikingly unequal ears on the right valve. Specimens of P. discus having the shell material preserved always show moderately high, convex ribs; the internal casts (in which form the species is generally found) have the ribs more or less squarish, and low. The specimens having the fewest number of ribs have the widest lateral areas or submargins. The type does not show the radial sculpture found in most cases on the ears of the left valve.

P, discus is closely allied to P, pabloensis but has the constant difference of larger size when adult and stronger rounded ribs instead of weak squarish ones. It occurs in approximately the same horizon as P, pahloenstM and seems to represent the latter in what is probably the equivalent of the San Pablo (upper Miocene) formation in the region south of the typical San Pablo Bay locality, although at some localities it has been found in beds of probable middle Miocene age.

About the head of Crescent Creek, near Oil City, Fresno County, P, discus is associated with the following: Ocinehra near caucdUna Trochita filosa Mytilus mathewsonii (?), Area sp. indet., and Valuta (?) sp. This appears to be an uncertain horizon in the Miocene.

Range.

Miocene (upper). Walnut Creek, Contra Costa County (Univ. of Cal. collection); Santa Margarita, San Luis Obispo County {J, H. Henry); Assuncion ranch, San Luis Obispo County (Fairbanks; Arnold; R. Mo ran); Huasua ranch, 20 miles north of Santa Maria, Santa Barbara County (C. E. Knecht).

Miocene Pecten8. 87

Miocene (middle or lower?) Roblar, 12 miles from Paso Robles, and on ranch of W. F. Gillis, 10 miles southwest of Paso Robles, San Luis Obispo County (J. P. Smith); Oil City, Fresno County (Eldridge).

Pecten (Plagioctenium) eldridgei n. sp.

PL XXV, figs. 3, 3a, 36, 4, 4a, 5, 5a, and 6.

Description. — Shell averaging about 20 millimeters in altitude, nearly as high as long, equivalve, somewhat oblique (the posterior portion being the longer), very thick and heav}', very ventricose, and with serrate margins; base unequally rounded; sides somewhat concave above and sloping at a moderately steep angle. Right valve with 19 or 20 small, rather low but sharply defined, squarish ribs; interspaces about one-half as wide as riKs, channeled, and with flat bottoms; surface of disk ornamented by numerous sharp concentric lines which loop back over the ribs; more or less prominent constrictions, indicating interrupted growth, are common on most specimens; hinge line equal to about three-fourths length of disk; anterior ear slightly longer than posterior, deeply notched, and ornamented by 3 or 4 prominent radiating ridges and numerous imbricating incremental lines; posterior ear rectangularly truncated and ornamented by 8 or 10 radiating ridges and incremental sculpture. Left valve similar to right, except that the ribs are slightly narrower and more rounded; ears similar to those of right valve except that the anterior one is not as deeply notched. Hinge similar to that of P. circularis except stronger and with the auricular crura much more highly developed. Adductor impressions very deep.

DlmeuMiom. — Alt. 20 mm.; long. 21 mm.; hinge line 15 mm.; diameter 15 mm.

This species is similar in respects to P, circularise but is characterized by its smaller size, greater ventricosity, thicker and heavier shell, deep adductor impressions, and more or less prominent constrictions. It sometimes attains an altitude of -15 milhmeters, as shown by fragments collected at the type locality.

eldridgei appears to be confined to the oil-bearing strata of the San Joaquin Valley, which arc probably San Pablo or upper Miocene in age.

The type, which is figured and is now in the United States National Museum, was collected in the hills south of the Dahney water wells, McKittrick district, Kern County. Named in honor of the late Mr. G. H. Eldridge, of the United States Geological Surve} .

Miocene (upper). McKittrick district, Kern County (Eldridge); Riiena Vista and McKittrick, Kern County (Watts).

Pecten (Plagioctenium) neahensis n. sp. PI. XV, figH. 2, and 26.

Descrriptioix, — Adult shell averaging about 45 millimeters in altitude, somewhat longer than high, subequivalve, subequilateral, prominently ventricose, especially for about the first 25 millimeters of altitude, after which it is sometimes more compressed; sides concave above; base evenly rounded; margins smooth. Right valve with 19 prominent rounded ribs, separated by somewhat narrower

88 Tertiary And Quaternary Pecten8 Of California.

interspaces; surface sculptured by fine incremental lirulse which loop back over the tops of the ribs; hinge line over one-half length of disk; ears subequal; anterior with 4 or 5 prominent radials, posterior with one or two less prominent ones; both ears sculptured by fine incremental lines; byssal notch rather prominent. Left valve a little less ventricose than right and with ribs narrower and more sharply convex above and the interspaces relatively broader; ears as in right valve.

Dimenmons. — Alt. 43 mm.; long. 50 mm.; hinge line' 28 mm.; diameter 28 mm.

This species is probably allied to P, circulariH and P, circularis var. but may be distinguished by its fewer and narrower ribs and longer hinge line.

The type (U. S. N. M. No. 5912) is labeled '' Neah Bay, Washington," and was collected by Lieut. J. G. Swan. The beds in the immediate vicinity of Neah Bay were found by the writer to be almost entirely unfossiliferous, so that it is probable that P. naahefisis instead of coming from Neah Bay, comes from some of the fossiliferous strata farther east, possibly from those in the vicinity of Clallam Bay.

Range.

Miocene. Clallam County, near (?) Neah Bay, Washington (J. (i. Swan). Peoten (Plagioctenium) pabloensis Conrad.

PI. XXVII, figs. 5, 5a, 6, 6a, and 7.

1857. Pecteji pabloeims Conrad, Pac. R. R. Rept., vol. 6, pt. 2, 1857, p. 71, pi. 3, fig. 14. 1888. Peden jxibloenniji Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 258 (in part). 1898. Pecten (? PUiffioctenium) pahloenm Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 703.

DeHcHptloru — Shell averaging about 35 millimeters in altitude, about as high as long, equivalve, equilateral, thin, slightly ventricose, and with smooth margins; sides sloping at a low angle and quite prominently concave above. Kight valve with 18 to 20 square, flat-topped, radiating ribs, which are narrower and less distinct laterally and become more feeble as the periphery of the disk is approached; interspaces about as wide as the ribs, flat bottomed and often separated from the principal ribs by impressed lines which give the interspaces the appearance of bearing intercalary riblets; whole surface of disk sculptured by tine concentric lines and, in some instances, more or less prominent lines showing interrupted growth; hinge line somewhat longer than one-half length of disk; anterior ear slightly longer than posterior, deeply notched, and ornamented by 4 or 5 coarse radiating ridges and sharp, raised incremental lines; posterior ear slightly concave behind, and covered by numerous incremental lines and several obsolete radiating ribs. Left valve similar to the right except that in some cases the ribs are slightly more rounded above, and the looped or wavy concentric lines are more conspicuous; ears similar to those of the right valve except that the anterior one lacks the deep byssal notch. Hinge as in P, circidarh except that the cardinal crura are very faint, while the auricular crura are quite prominent.

Miocene Pecten8. 89

Dimensions, — Alt. 35 mm.; long. 35 mm.; hinge line 20 mm.; diameter 6 mm.

The measurements given above are from an average-sized specimen. One left valve examined was 50 millimeters in altitude, but this size is exceptional for specimens from the t'pe locality (shore of San Pablo Bay).

The prominence of the ribs seems to be the most variable factor in this species. As a rule the ribs are sharp and well defined until the shell attains an altitude of 10 or 15 millimeters, when they broaden out and become low, those near the sides almost losing their identity in some specimens. One specimen examined retained the elevated and sharply defined ribs up to an altitude of over 25 millimeters, and ver}' much resembled a young P, civcidaru var. cequlsidcatics,

P, pabloeisu is so far known only in the San Pablo, or upper Miocene formation. At the type locality, on the shore of San Pablo Contra Costa County, a bed several feet thick is made up almost entirely of valves of this species. At this locality P, pahloen-uii i.s associated with P, cramlcardo and P, (?).

Raxge.

Miocene (upper). Shores of San Pablo Bay, Contra Costa Count}' (Newberry; Merriam; Arnold).

Pecten (Pseudamusium) lompicoensis n. sp.

PI. XXIII, fig. 5; PI. XXVII, fig. 8.

Description, — Adult shell averaging about 11 millimeters in altitude, subcircular, inequivalve, thin, compressed; margins smooth. Right valve ornamented externally by numerous sharp, elevated, equal, equidistant, imbricating, concentric lamellae; hinge line equal to one-half length of disk; ears unequal; anterior nearly twice as long as the posterior, arcuately truncated and sculptured by regular, sharp, imbricating, concentric lamelhe and or 7 faint radials; posterior ear short, somewhat obliquely truncated and sculptured by concentric lamella?; byssal notch only faintly indicated. Left valve sculptured by concentric lamella* similai- to those of the right, and, in addition, having numerous fine radiating stria?, which usually become obsolete near the periphery in the adult shell; ears similar to those of the right valve, except that in the specimens examined no ludials were noted on the anterior one. Hinge siuiilar to that of P, randflphl.

Dlnienilons {of slightly (/7'fcd s/Mchnen). — Alt. 11.5 mm.; long. 11 mm.; hinge line 5.5 mm.

This beautiful little PecUn is allied to jhckJuiml but is distinguishable from the latter by its much more prominent and regular concentric lamelbe, and by its well-defined ears, the anterior one of which on the right valve is relatively much shorter and broader than the analogous one in P. ptckhdint. The byssal notch in P, lonipleoensls is also only faintly indicated, while in P. ptckhaml the notch is profoundly developed.

P, is known only from the Miocene (exact horizon doubtful) shales at the head of Lompico Creek, Santa Cruz County, where it is associated with a Phdcoldts resembling acutllineatics Conrad.

Range.

Miocene. Head of Lompico Creek, Santa Cruz County (Newsom, Arnold).

W) Tkhtiakv And Quaternary Pecten8 Of California.

pErmcN (PsEUDAMuaiUM) PEDROANU8 Trask. PL XXVIII, figs. 4 and 5.

IH.V>. f'Uii/jMU/rna Pedrtxina Traak, Proc. Cal. Acad. Nat. Sci., vol. 1, 1856, p. 93, pi. 3, tigs. 1, la.

I'lmjio/ftorfui trunaita Traiik, Proc. Cal. Acad. Nat. Sci., vol. 1, 1856, p. 94, pi. 3, fig. 3.

IH.Vi. Hfi/jiotiUfina anwiifUiMTrHiikf Proc. Cal. Acad. Nat. Sci., vol. 1, 1856, p. 94, pi. 3, fig. 2.

1H61I. /V/Y/'// Pfdrfpfinus Trask, Gabb, Pal. Cal., vol. 2, 1869, p. 60.

18HM. J't-rten pflrrMiniis Trask, Cooper, Seventh Ann. Rept. Cal. St. Min., for 1887, p. 258.

1898. PerU'n j*edrrxiutJis , Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 705.

The original description is as follows:

Ihfxcrtptlou. — '"Shell compressed, subtriangular, with 8 or 9 flatly rounded concentric annulations, which are nearly as distinctly marked on the interior of the valve for half the height from the ventral margin; beaks acute at the a|>ex. and as high as the line of the auricles; anterior auricle rounded in front, and has a small, thin fold extending from the umbone to the center of its anterior margin, and is covered with about 13 small, rounded, radiating stria?, which converge at the beak; beaks at the anterior third; subacute; anterior margin rounded, and somewhat produced; ventral margin smooth' arched; margin rounded, becoming slightly arcuate toward the dorsum of the shell: auricle angulate and obtusely truncate posteriorly."

IHiiamlffm, — Alt. 30 mm.; long. 37 mm.; hinge line 13.5 mm.

The above is Doctor Trask's original description with measurements of the type. Gabb has the following to say of this species:"

'*In 185*5 Doctor Trask named three species of PJagioHUmui giving full descriptions and well-executed figures as above. His specimens are casts of a number of distorted Pectenn perhaps normally a little o})lique, but in most cases with the obliquity exaggerated by pressure. They l;>elong without question to but one species, and the first name given have to retained. I have carefully studied the specimens, and have visited the locality from which they were o])tained. The deposit belongs to the bituminous shale of the upper Miocene, which underlies the whole or the greater part of the Los Angeles plain, crops out on the beach at San Pedro, under the post- Pliocene, and has been reached by artesian borings under the city itself.

''The species is about an inch in diameter, ears subequal, shell thin, perhaps nonnally a little oblique, and the shell substance contains a few concentric undulations or ribs, which are retained in the cast. No specimens show any shell preserved; so that if there was any surface sculpture, it is as yet unknown.''

The writer has examined several specimens of this species collected by Mr. W. L. Watts in the oil fields of southern California. Some of these specimens show the original shell material, which, upon a careful examination, revealed no trace whatever of any but the concentric undulating sculpture.

The best preserved specimens of this species examined by the writer were taken from the Third street tunnel in Los Angeles by Mr. Homer Hamlin and are now in the U. S. National Museum (No. In several of these specimens the original shell material is quite well preserved, and in one case Camptonectes

a Pal. Cal.. vol. 2. 1869, p. 60.

Miocene Pectens. 91

sculpture of numerous faint radiating ribs, microscopic striae, and numerous more or less prominent lines of interrupted growth were plainly seen. The sculpture was very similar, if not identical, to that of P. randolpliL P, Wr<?ani/ and P, randolph are also alike in shape and general characteristics, and the only difference noted in a comparison of the two was the slightl\ larger size and more prominent undulated disks of the former. A careful examination of better material of the fossil form, if any is ever obtained, may lead to a union of the two species.

The Third street tunnel beds are of soft bluish shale, which yielded besides densldathraia -n latianritu Nassa ii. sp. ?, Macoma sp. indet.. Area taulticostata Lima hamlinl Bwclmun sp. indet., Neverita rtdiizlana Afitarte'i sp., Prieiie oregoneihHtH (htrea veatchri. PJeurotonat sp. indet., ,carditoid, coral, bird bone, and crab claw.

This fauna indicates a horizon the same as that of the San Diego formation, and is Pliocene (probably lower) in age. It therefore seems likely that P, pedroanm which has heretofore been considered a typical Monterey or middle Miocene species, also occurs in the Pliocene, and may possibly be Dall's recent deep-water species, P. randolph.

kan(;e.

Pliocene (lower). Clark estate, Los Angeles and Puente Hills, Los Angeles County (Watts); Third street tunnel, Los Angeles (Hamlin); Joyce wells, Whittier district, Puente Hills, Los Angeles County (Eldridge).

Miocene. San Pedro (Trask, Gabb); 4 miles south of McKittrick, Kern County (Eldridge).

Pecten (Propeamusium) stanfordensis n. sp.

Pi. Xxiii. %. 4.

DescHptum, — Shell averaging about !♦ millimeters in altitude, subcircular, equivalve, equilateral, thin, only slightly ventricose, and with smooth margins. Right valve with the exterior surface ornamented by numerous fine concentric undulations and, in somc cases, microscopic radiating strite; interior with lU to 12 prominent, rounded, equidistant ribs extending from the umbo to or near to the periphery of the disk, those ribs nearest the center of the shell being straight, while those near the sides are somewhat arcuate toward the central rib; hinge line slight longer than one-half the length of the disk; ears equal in length, and ornamented by the fine concentric undulations; anterior ear with a small byssal notch. Left valve similar to right, except that its anterior ear lacks the byssal notch.

Diniefhsloihs, — Alt. 7 mm.; long. 7.2 mm.; hinge line 4 mm.; diameter 1.2 mm.

In the specimens showing the original shell material the internal ribs sometimes break out and leave corresponding grooves in the disk, thus showing that they are of a rather secondary growth compared to that of the disk.

This species is somewhat similar to P, InterradiaMis of the Tejon (Eocene), but may be distinguished from it by having 10 to 12 instead of 8 ribs, being

Miocene Pectens.

sp. On the ridge between the Upper and Lower Ojai Valleys, Ventura County, Mr. Eldridge has found lompoceniii< with the following species, in beds which he thinks are of lower Miocene (Vaqueros) age: Peettm eniHsicardo Turritdla (cf.) hoffmanni Phacoides sp. (flat), Ostrea sp., Nansa sp., Dentalium sp., Chixme sp., Leda sp. BaJanm sp., Tritonhcin or Fu,uj< sp.

Miocene (lower i). Four miles south of Lonipoc, Santa Barbara County (F. M. Anderson); ridge between upper and lower Ojai valleys, Ventura County (Eldridge).

Pecten (HiNxiTEs) (irav.

PI. XXIX, fi. 1, 2,

1826. Hinnites gigantem Gray, Ann. Phil., scr., vol. 12, 1826, p. 103.

1834. Illnnita ponhonl Conmd, Jour. Acad. Nat. Sol., Phila., vol. 7, p. 182, pi. 14.

1843. Ifinnites gigonteus (TiTa.yy Sowerhy, Thes. Conch., vol. 1, Ilinnites, p. 80, pi. 20, fijjs. 3-5.

1853. Hinnites gigaiiteus Gray, Reeve, Conch. Icon., vol. 8, Ilirinites, Oct., 1853, sp. 2, pi. 1, fig. 3.

1857. HinniUs crassa Conrad, Pae. R. R. Rept., vol. 7, pt. 2, p. 190, pi. 2, figs. 1 and 2. ,

1863. Ilinnites gigatiteus Gr&yy Carpenter, Brit. Afsn. Rept., 1863, p. 645.

1863. Jliniiites craififa ConrB,(\, Brit. Assn. Rept., 1863, p. 595.

1869. Hlnniies giganteus Gr&y, (xabb, Pal. Cal., vol. 2, 1869, p. 105.

1887. Hinniles giganteus Gray, Whiteaves, Trans. Roy. Soc. Canada, vol. 4, sec. 4, 1887, p. 119.

1888. Pecten {Ilinnites) giganirns Gray, Kiister, and Conch. -Cab., vol. 17, pt. 2, 8pondylu8 und

Pecten, sp. 228, taf. 65, figs. 9 and 10. 1888. I finnitcs gigantens GrAy J Seventh Ann. Rept. Cal. vt. Min., 1888, p. 243 (Santa Rosa

Island record exceptetl). 1892. Hinnites giganteiis Gray, Keep, West Coast Shells, 165, fig. VM>. 1892. Hinnites giganteus Gmy, Williamson, Proc. U. S. Nat. Mus., vol. 15, 1892, p. 193. 1898. Ilinnites giganteus Gniy, Dall, Trans. Wagner Free Inst. Sci.. vol. 3, pt. 4, 1898, p. 711. 1898. Ilinnites crassa Conrad, Dall, Trans. Wagner Free Inst. 8ci., vol. 3, pt. 4, p. 711.

1903. Pecten {Ilinnites) giganteus Gray, Arnold, Mem. Cal. Acad. Sci., vol. 3, pt. 2, 1903, p. 115.

1904. Pecten {Hinnites) giganteus Gray, Keep, West American Shells, p. 42, fig. 22.

— Shell averaging about 75 millimeters in altitude, usually not quite so long as high, irregular, inequivalve, generally inequilateral on account of attachment to irregular surface; shell quite thick; margins smooth. Right valve more ventricose than left, ornamented by 9 to 18 narrow, irregular, prominently squamose ribs, ))etween which in the flat interspaces are less prominent raised lines similarly sculptured; hinge linc more than one-half length of disk; ears subequal, and more or less prominently sculptured by fine, squamose, radiating lines; b3'ssal sinus sometimes visible. Left valve less ventricose than right, otherwise similar. Hinge rather narrow and heavy; fosset deeply excavated, oblique, narrow, and angular; hinge is dark purple in living shells.

DimenHi(>ni<, — Alt. 70 mm.; long. 65 mm.; hinge line 40 mm. in length, 10 mm. in width; diameter 85 mm.

The young of this species is free swimming until an altitude of about 20 or 30 millimeters is reached, when they become attached to some fixed object. If this object happens to have an irregular surface, as is generally the caae, the shell grows irregular in consequence. The young, up to the time of attachment, are indis-

94 Tertiary And Quaternary Pectens Of California.

tinguishable from the young of P, hastahis and varieties, except possibly that the ribs on the right valve of Ilinnltes are rather more irregular in size than those of CMwiiys,

After comparing Conrad's types of Hinnitefi crassa with a large series of living HlmiiteH glganteuHy the writer has no hesitation in pronouncing the two species identical. The types of H, drama were collected from the upper Miocene near Santa Margarita/ (See PI. XXIX, fig. 1.)

P, {Ilinnites) giganteus ranges from the lower Miocene to the living fauna. Mr. Eldridge found it associated with Tunntella hoffmcmni in a small gulch east of Wiley Canyon, Ventura County.

Range.

Living. Strait of Fuca to San Diego (Cooper); Quatsino Sound, B. C. (Dawson). Pleistocene. Santa Barbara to San Diego (Cooper); upper and lower San Pedro

formation, San Pedro (Arnold). Pliocene. Pacific Beach, San Diego (Arnold); Ventura County, Los Angeles County

(Cooper). Miocene (upper). Santa Margarita, San Luis Obispo County (Conrad). Miocene (lower). Gulch east of Wiley Canyon, Ventura County (Eldridge). Miocene (horizon?) Carrizo Creek district, San Diego County (Bowers).

PLIOCENE PECTENS. [Those known firKt to appear in the Pliocene fonnations.]

Pecten (Pecten) auburyi n. sp. PI. XXXIII, figs. 2 and 2a; PI. XXXIV, figs. 2 and 2a. 1900. Pecten indet., Merriam, Bull. Cal. St. Min. Bureau, No. 19, 1900, p. 222.

Description, — Adult shell averaging about 60 millimeters in altitude, somewhat longer than high, inequivalve, plano-convex, equilateral, and with smooth margins. Right valve convex and ornamented about 16 or 17 prominent, rather narrow, convex-topped ribs; interspaces slightly narrower than the ribs, and with concave bottoms; whole surface sculptured by prominent, tine, sharp, subequal incremental lines; hinge line less than one-half length of disk; ears subequal and convex; anterior ear with two or three obsolete radiating ridges, prominent concentric sculpture, and small byssal notch; posterior ear with concentric sculpture only. Left valve flat or slightly concave, ornamented by 16 or 17 prominent, narrow, convex-topped ribs, which are separated by deep, almost flat-bottomed interspaces slightly wider than the ribs; whole surface sculptured by prominent, fine, sharp, equal, concentric lines; ears slightly concave, rectangularly truncated, and sculptured by fine, sharp, concentric lines.

Dimensions, — Alt. 47 mm.; long. 50 mm.; hinge line 21 mm.; diameter 12 mm.; umbonal angle (left valve) 93.

This species is quite closely related to P, lecontei but is distinguishable from the latter by the smaller angle at the apex (102° in the latter), much narrower sharper ribs, and stronger sculpture on the right valve.

P, avhuryi has so far been found in beds of probable lower Pliocene age. About 1 mile east of the Chandler well, Puente Hills, Los Angeles County, it is

Pliocene Pecten8. 95

associated, according to Doctor Merriam (see Merriani, 1900, p. 222), witli Cancelhiria 2 n. sp., Crepklula sp. indet., DriUui sp., II/nn!tes near glgantcHS Natlca {Xecerlta {aff.) reduzlamu oreganenaiH Ranella eaUfornica and Trochlta sp, indet. At Olinda, Puente Hills, Orange County, Mr. Eldridge found ayhuryl with the following lower Pliocene fauna: Pedeti ((Mhlryf\ P, watts! P. owenL var., Priene {aff,) arego/unsis Oardlum Neverita recluzuntn PhacoUles califoinlcuty,, Fuhws harharensls,, Area mnltieoxtata (?), Nasa jterphtgulit (?), Chione Hp,,, Li:da taphrUi, Flsnurideo murlna,, JVassa fossata Phacoide<'< ruhthofeni Phaoldes nuttalli Phacoides (cf.) acutllineatus,, Cardiu/n {cf,) corhln Chlone sp., Dentalmm neohexagonxim, Sol en {rf,) TurTltdhi iooperl, rngom Asfyris sp., Cancelhiria n. sp., CaUloxtoma codatniH Modiolus (cf.) recttiJ< Bulla punctulata,, and Dentalium n. sp. (like Miocene form).

The type specimen is from the tirst-mentioned localit}-, and is now in the State Mining Bureau. Named in honor of Mr. Lewis E. Anbury, State Minenilogist of California, through whom the writer was enabled to procure the valuable Pecten material in the State museum.

Pliocene. Locality 88, 1 mile east of the Chandler wells, Puente Hills, Los Angeles County (Watts): Several localities in the vicinity of Olinda and Brea Canyon, Puente Hills, Orange County (Eldridge).

Pecten (Pecten) bellus Conrad. PI. XXXI, figH. 1 and \n.

1857. Janira bella Conrad, Proc. Acad. Nat. Sci. Phila., fnr 1856, p. 812.

1857. Janira bella Conmd, Pac. R. R. Rept., vol. 6, 1857, p. 71, pi. 3, fig. 16.

1869. Janira bella Conrad, Gabb, Pal. Cal., vol. 2, 1869, p. 105, pi. KJ, %. 20.

1888. Janira bella Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 188S, p. 244.

1898. Peclen [Pecten) bellus Conrad, Dall, Trans. Wagner Free . Sci., vol. 3, pt. 4, 1898, p. 704; not

P. bell in McCoy tente D&W, 1898). 1900. To/anp. indet., Merriam, Bull. Cal. vSt. Min. Bureau, No. 19, p. 222, table 111. 1903. Pecten {Pecten) bellus Conrad, Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, j). 103, pi. 21, figs. 1, 2.

—HheW large, thin, inequivalve, elegantly, radiately ribbed. Left (upper) valve slightW convex, the point of greatest convexity })eing generally about one-fourth the distance from the apex toward the ventral margin; between this point of greatest convexity and the apex there is a deeply depressed area, the depression generally not affecting the two outer ribs on each side, which inclose the depression on the sides; surface of left valve ornamented })v 18 or 14 prominent, flat- topped, sometimes faintly bicarinated, radiating ribs, which have flat, sloping sides; these ribs become broader, less elevated, and less sharply angulated near the periphery} in the adult; interspaces slightly wider than the tops of the ribs, wMth slightly rounded bottoms; whole surface of left disk covered with line, sharp, concentric, regular lamelhe; ears rather small, subequal, slightly concave, finely concentricall}' lamellated, .separated from the disk by an impressed line. Right (lower) valve prominently convex, the point of greatest convexity being about one-third the distance from the apex to the ventral margin of the disk; the imibo in this valve curves sharply and meets the plane of the ears at an angle of about 90 degrees; surface

96 Tertiary And Quaternary Pecten8 Of California.

of right valve ornamented by 14 or 15 prominent, nearly flat-topped, square radiating ribs, some of them with one or two longitudinal obsolete lines; the ribs become somewhat le.ss elevated and the sides more sloping as the periphery is approached in the adult; surface of right disk ornamented with close, fine, squamose, concentric wrinkles; ears subequal, arched, covered with crowded, elevated kimellfe: byssal notch small.

DhntnimonH, — Alt. 80 mm.; lat. loS mm.: diam. 32 mm.: length of hinge line, 45 mm.

The description, measurements, and figures are of Gabb's type specimen of Janira delhi (No. 960, Collection Academy Natural Sciences, Philadelphia), which was kindly lent to the writer by Prof. 11. A. Pilsbry, curator of Mollusca.

P, titearnail and dugensis are distinguishable from Mhm by the more numerous (25 or 28 in the first, 20 or 22 in the second), narrower, sharper defined, radiating ribs on the right valve, and by the evenly rounded, piomiiiently and evenly lamellated ribs of the left valve. heniphtlli is distinguishable from helluM by its smaller size: by having on the right valve more numerous (15 or 16 in the former), round-topped, narrower, nearly perpendicularsided, radiating ribs, which retain their prominence for their entire length; by the less convexity of the disk: and by the more numerous, narrower, and more elevated radiating ribs of the left valve. P. ht-mphUll has the same depression below the apex in the left valve, but the lesser convexity of the rest of the disk lessens the prominence of the depression, which is so marked in most specimens of P, hell, P, txcarutu is distinguishable from -t/Zw by its smaller size, greater convexity of right valve, greater conc*avity of left valve, greater of ribs, and by the auxiliary ribs in the left valve.

After a careful comparison of a large series* of P. with Conrad's descrip tion and figure and Gabb's figure and type specimen, the writer has no hesitancy in adopting the synonymy given at the beginning of this article. Dall is of the opinion that Conrad's species and that of Gabb aiv different. Tliis idea was prolmbly caused ])v the exaggeration of the bicariuation of the ribs in Conrad's figure. Several of the specimens of htlluM examined by the writer show this bicariuation to a greater or less degree, although as a rule the rib are nearly smooth-topped. A large series of P. . and P. hemphill! show the differences enumerated in a previous paragraph to be constant for the adults. The young of species up to an altitude of 20 millimeters are nearly identical in appearance.

P. so far as known, is confined to the Pliocene. It occurs abimdantly in the Pliocene formation on Packards Hill, Santa Barbjini, and in other localities in the vicinity. The type was obtained near Santa Barbara.

RANt.E.

Pliocene. Santa Barbara (Conrad: Gabb: Yates: Cooper: Arnold): Top of hill. Long Tom mine, Kern County (Watts): Eureka Canyon, west side, near mouth, Ventura Count}* (Eldridge): Rincon asphalt mine, Santa Barbaia County (Watts): Loc. 33, east side of Piru Creek, near railroad bridge, Ventura Coimty (Watts): i Temescal Canyon, north of Santa Monica, Los Angeles County (Rivers).

Pliocene Pectens. 97

Pecten (Pecten) coALiNcsAENsrs n. sp.

PI. IV, figs. 4, 4a, and 5.

Description, — Shell about 45 millimeters in altitude, longer than high, planoconvex, or nearly so, equilateml, and with smooth margins. Right valve ventrieose and ornamented by about 20 ribs which have narrow, somewhat convex tops, and sides which slope at angles of about 46; interspaces quite deeply impressed, channeled, and flat bottomed; surface sculptured by fine incremental lines; hinge line slightly longer than one-half length of disk; ears equal, convex, and ornamented b\' 2 or 3 obsolete radiating ridges and numerous tine incremental lines. Left valve flat, with 19 prominent (*convex ribs, a surface sculpture of tine regular incremental lines, and concave ears which are slightly obliquely truncated.

DlmennionA, — Alt. 45 mm.; long. 52 mm.; hinge line 28 mm.; diameter 18 mm.

This species is easily distinguishable by tin* peculiar shape of the ribs on the right valve. The type (right valve) was collected by Mr. L. D. O'Neal from beds of probable lower Pliocene age near Coalinga, Fresno County, and is now in the collection of the Leland Stanford Junior University. A left valve, which is undoubtedly of this species, was found by Mr. Watts near Kreyenhagen's ranch, Fresno County, and is now in the collection of the California Academy of Sciences. This left valve measures as follows: Alt. 35 mm.; long. 37 mm.: hinge line 13 mm.

Pliocene (lower). Coalinga, Fresno County (L. D. O'Neal): Kreyenhagen's ranch, Fresno County (Watts. Anderson, Arnold).

Pecten (Pectex) iiemphilli Dall.

PI. XXXIll, lirH. S, 3f/, and \M.

1879. Pertm hemphilli Dall, Proc. U. S. Nat. Mas., vol. 1, 1879, p. 15.

18HS. IWten hemphUVi Dall, Cooper, Seventh Ann. Kept. Cal. St. Min., 1888, p. 2o7.

1898. Pt'cten (Pertm) hcmphUli Dall, Trans. WajrniT Free In.Jt. Sci., vol. pt. 4, 1898, p.

1903. Pt'deii [Pecten) hemphilli Dall, Arnold, Meui. Cal. Acad. Sci., vol. 3, 19()3, p. 105.

Di'Acriptuni, — Shell of medium size, thin, ineijuivalve. Upper (left) valve flat or slightly concave, with a concave depression between middle of valve and umbo; surface of this valv( sculptui'ed ))y or 17 very prominent, rather narrow radiating ribs, which are nearly flat-topped and have nearh' sides; interspaces wider than ribs, with rounding bottoms; ttne incremental! lauKlhv cover the surface of this valve; ears square-cornered and concave, covered with incremental lamelhe. Lower (right) valve convex, the convexity being most apparent between middle of valve and umbo; sculptured by prominent squarish ribs, which are similar to those on the upper valve, exce|)t that they are slightly broader and have a more rounded top; whole surface sculptured by very fine incremental lines; ears similar to those of upper valve convex, the right one having 3 or 4 radiating ridges and a small byssal notch. 17260— No. 47—06 7

98 Tkrtiary And Quaternary Pecten8 Of California.

— Alt. 56 mm.; long. 63 mm.; diam. 15 mm.; hinge line 28 mm.

This species is readily distinguishable from P. Hteiumsll. and (Hegemis by its smaller size, greater convexity of lower valve, and fewer ribs. Distinguishable from helliii< by smaller size, flat or concave upper valve, and narrow, more elevated and prominent, radiating ribs. Common in the upper horizon of the Pliocene at Pacific Beach, and also in the strata exposed on Tenth street, near Russ School, San Diego.

Pliocene, Temescal Canyon, north of Santa Monica, IjOs Angeles County (Rivers); Pacific Beach, Russ School, and ''San Diego well," San Diego (Hemphill, Dall, Arnold).

Pecten (Pecten) lecontei n. sp.

PI. XXXIII, figs. 4, 4</, ami 4/>.

Description, — Shell averaging about 60 millimeters in altitude, longer than high, plano-convex, equilateral, and with smooth margins; base evenly rounded; sides concave above. Right valve convex, and ornamented about 18 prominent round-topped, perpendicular-sided, smoothish ribs, separated by interspaces, which are narrower than the ribs and have nearly flat bottoms; surface sculptured by fine wavy incremental lines, which are generally worn off from the tops of the . ribs; hinge less than one-half the length of the disk; ears somewhat convex; the anterior with 2 or 8 broad, nearly obsolete, radiating ridges, imbricating incrementiil lines, and a mther small byssal notch: the posterior recttingularly trun(?ated, and with fine incremental sculpture. Left valve flat or slightly concave, ornamented by about 17 prominent rounded ri})s, which are separated by interspaces about equal in width to the ribs; surface sculptured by numerous fine, sharp, regular, raised, increnKntal lines; ears concave, rectangularly truncated, and covered by fine sharp incremental lines.

DlmeiinlonH. — Alt. 59 mm.; long. 65 mm.; hinge line 29 mm.; diameter 18 mm. ; umbonal angle (left valve) 102.

This species is distinguishable from dlegentilii,, P. hell P, and other members of this group by the number and convexity of the ribs on the right valve. The left valves of P. leamtei and P, diegenHh are somewhat similar, although the former has fewer ribs and is generally slightly more concave.

P, lecontei has so far been found onh' in the Pliocene of Cerros Island, where it is associated with reutchll, P. and Ostrea veatchiL The type is now in the (collection of Delos Arnold. Named in honor of the late Prof. Joseph Le Conte, of the University of California.

Pliocene. Cerros Island, Lower California (Lniversity of California).

100 Tertiary And Quaternary Peotens Of California.

PeCTEN (PeCTEN) 8TEARNSII Dall.

PI. XXXII, figs. 1 and

1869. Janira dentaia Gab]> (not Sowcrby), Pal. Cal., vol. 2, 189, p. 104 (in part).

1879. Pecten Mearmii Dall, Proe. U. S. Nat. Miis., vol. 1, 1879, p. 14.

1888. Janira deniata Cooper (not Sowerby), Seventh Ann. Kept. Cal. St. Min., 1888, p. 244 (in part).

1898. Pet-ten ( Peoteu) stearnsii Dall, Trans. Wagner Free Inst. St-i., vol. 3, pt. 4, 1898, p. 706, pi. 26, fig. 5.

1900. VoUi pp. indet., Merriam, Bull. Cal. St. Min. Bureau, No. 19, 1900, p. 222, table 4.

190:i Pectm (Perten) nteaiiwii Dall, Arnold, Mem. Cal. Sci., vol. 3, 1903, p. 106, pi. 12, fig. 3.

— Shell of medium size, subcircular, iiiequivalve, concavo-convex, thin; right valve slightly convex, with about 2f> regular, even, square ribs, separated by channeled interspaces somewhat narrower than the ribs: the top surface of each rib is flattened with a broad, shallow groove in the middle, with one or two faint riblets on each side of the groove; whole surface co\'ered witJi concentric lamellae which are much tiner and about twice as crowded as those of the left valve; left valve flattened or concave, with about 24 regularly rounded, vaulted, even ribs, separated by slightly wider channeled interspaces; the whole surface covered with fine, shai*p, concentric, regular lamelhv, a little looped })awkward over the tops of the ridge; ears of this valve concave, with obsolete mdiating ridges, and tine, concentric lamella*; ears of right valve sulwqual, arched, covered with crowded, elevated lamella*; byssal notch very small.

DhneHHUmsi. — Alt. 62 mm.; long. 71 mm.; diameter 14 nmi.; hinge 25 mm.

According to Doctor Dall this is the precursor of ilivfjenatH from which it differs by having 5 or more ribs, which in the adult have a conspicuous medial sulcus.

P. Htianmi so far as known, is contined to the Pliocene. It is quite abundant at Pacific Beach, near San Diego, where it is associated with P, P, hemj)- h!Uf\ Opnlla O. anomala Scola Ptcten jmviheltel and other unique forms. In a well at San Juan Capistrano it was found by Watts associated with TnrrlteUa axtptn Yenencardia ventrlami Area tnlhieata inendlco etc. Two left valves have been found in the Pliocene at Deadman Island, near San Pedro.

Pliocene. Temescal Canyon, Santa Monica Mountains, Los Angeles County (Watts, Rivers); San Pedro (Arnold); San Juan Capistrano, Orange (\)unty (Watts); Pacific Bleach, near San Diego (Hemphill, Stearns, Dall, Arnold); Third street tunnel, Ijos Angeles (Hamlin).

PI. XXXIII, fis. 1 and la; 1*1. XXXIV, %. 1.

1888. Jnulm deniata Cooper, Seventh Ann. Kept. Cal. St. Min., 1888, p. 244 ((iuaternarv records). 1903. Pecteu {JWten) dentatm Arnold, Mem. Cal. Acad. Sci., vol. .S, p. 105 (PU'iMtoceno ivoord).

Dernptiofi. — Shell similar to P. exvtnmtuH except averaging larger and with the following differences: Right valve, somewhat less convex, has li> or 20 broader. Hatter ribs, which are separated bv relatively broader interspaces that occasionally show faint intercalary riblets or faint longitudinal striations. Left valve with fcwiM* ribs

Pliocene Pectens. 101

than p. and having no intercalan' ri blots, or else faint ones, which become obsolete near the periphery of the dik; ears slightly le.s.s concave than in fM'cavafKK

Dtm(<7iloiii<. — Alt. 69 mm.: hinge line to ventnil margin (right valve) 67 nmi.; long. 73 mm.; hinge line 35 mm.; diameter 24 mm.; umbonal angle (left valve) 98".

All of the Pleistocene spix'imens of the group of which f.fxurafus is the living representative have the constant differential characteristics above enumemted. These differences are so constant and so pronounced that they are deemed by the writer to be of specific importance.

A fragment of a right valve in the California Academy of Si'iences from the Pleistocene of Ventura Countv is over 120 millimeters in length.

The type of this species (a right valve) is from the upper San Pedro formation at San Pedro, and is now in the collection of Delos Arnold. The cotype, a left valve from the Pleistocene of Ventura (>ounty, is now in the (collection of the California Academy of wSciences. The horizon of some large specimens of this species in the Philadelphia Academy collected by Mr. Hemphill near San Diego is uncertain. Named in honor of Gen. A. W. Vogdes, U. S. Armv.

Pleistocene. San Pedro (Arnold); Ventum County (Bowers); San Diego (Hemphill). Pliocene (?). San Diego (Hemphill); Cholas Valley, nejir San Diego (Stearns).

Pecten (Patinopectex) CAURiNrs Gould.

PI. XXXVIII, figs. 1, If/, and 1//; PI. XXXIX, figs. 1 and 2.

1850. Pecten cnarinm ( Jould, Proc. Host. Nat. Hist., vol. 3, 150, p. %h.

1852. Pecten caannns Wilkes Expl. Exped., vol. 12, p. 458, figs. 569, 569/, 569?;.

1865. Pecten Heermanni Conrad, Proc. Acad. Nat. Sci. Phila., vol. 7, 1855, p. 267 (not P. (Lyrnpecten)

ffeerninnni Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, j). 701, nor Pecten If eerinanni

Nautilus, vol. 14, 1901, p. 117, P. eatrelldniLs Conrad). 1857. Pecten Meekii Conrad, Proc. Acarl. Nat. 8ci. Phila., for 1856, 1st ser., vol. 8, 1857, p. :U8. 1857. Pectm Meekii Conrad, Pac. R. R. Rept., vol. 7, pt. 2, 157, p. 190, 1, fig. 1. 1863. Amumim canrinutn Gould, Carpint4'r, Brit. As-n. Rept., 1863, p. 645. 1863. Pecten Carpenter, loc. cit., ]). 645 (not P. Jay, Perry's Voyage, 1856);

profHtlufus lur. rif., p. 679 (not Conrad, 1849). Flile Dall, lh98. 1886. Not Pectm caitrinnH Dall, Bull. Mus. Comp. Zool., vol. 12, p. 216, pi. 5, fig. 4, 18S6(=P.

vancoureroiitiii W hit eaves ) . 1888. Pecten caurinns Gould, Kiister and Ko})elt, Conch. -Cab., vol. 17, pt. 2, Spondylus und Pecten,

sp. 108, p. 152, tiil. 43, fig. 1. 1888. Amiiiinm murinus (ioidd, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 228 (excepting

"Japan"). 1888. Pecten propntnlns Coo]\tT, loc. cit., p. 258 ( " Pl River, Humboldt County"). 1H89. Not Pecten ctmrinuA Dall, Bull. U. S. Nat. Mus., n). .37, 1889, 5, fig. 4 mncovnrenms

Whiteaves). 1892. Perfen raurinux Gould, Williamson, Proc. V. S. Nat. Mus., vol. 15, p. 193. 1892. Amiuvunt caurinum (iould, Keep, West Coast Shells, 1892, p. 168. 1898. Pecten {Patinopecten) (iouM, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898,

p. 710. 1903. Pecten [Patlnopectni) cmrinns Gould, Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 107, pi. 13,

fig. fi.

1903. Not Pecten caurinns Dall, Bull. V. S. Nat. Mus., no. 37 (reprint), pi. 5, fig. 4, (=P.

eancoii ?v'/t///*m Whiteaves ) .

1904. Pecten caurinns Oould, Keep, West. Am. Shells, pp. 38-39.

102 Tertiary And Quaternary Pectens Of California.

DencHpthm, — Shell avemging about 150 millimeters in altitude, slightly longer than high, valves much compressed (the right generally slightly more convex than the left), equilateral, and with smooth margins; sides straight or only slightly concave above. Right valve with 20 to 25 strong, flat-topped, squarish ribs, which, in some well-preserved specimens, show faint obsolete radial striae; interspaces flat-bottomed and about equal in width to the ribs; whole surface of disk sculptured by fine incremental lines; hinge line less than onehalf length of disk; anttu'ior ear only very slightly longer than posterior, ornamented with fine, sharp, incremental lines, but generally having no radial sculpture whatever; byssal notch prominent; posterior ear rectangular Ijehind, and with sculpture similar to anterior. Ieft valve slightly less ventricose than right, with narrow rounded ribs and wide con cave -bottomed interspaces; surface ornamented by fine, regular, raised, wavy, concentric lines, and sometimes more or less tesselated; ears truncated and sculptured with sharp incremental lines and sometimes by obsolete radiating ridges.

r/?wA/?.v. —Alt. 105 mm.; long. 110 mm.; hinge line 4S mm.; diameter 15 mm.

The measurements are for a specimen under the avemge in size.

This species has caused considemble confusion in the nomenclature of the West Coast. In 1855 Conrad described a couple of small right valves of caurhnui and named the species Pecten IFeerDiann!, The following is his original description and notes (see synonym} above): '*Suborbicular, thin, compressed; ribs about 21, square, smooth; ears moderate in size. Locality, California. Doctor Heermann. Allied to P, fhn'eua of the Virginia Miocene, but very distinct; only two inferior valves were obtained; slightly convex." The type of P, IleernHmiu (so labeled in Conrad's own writing), and the other speciijnen referred to in the description are now in the Philadelphia Academ} of Sciences, where they were examined and photographcnl ])v the writer. They are both right valves of young P, caurinv and undoubtedly came from the unique brozoan marl of Santii Barbara, both specimens showing the characteristic matrix and blue-gray color of specimens of P, cfinrlnm from that locality. Some time after 1855 Conrad la})eled a P. and also some fragments of P, miguIsnsv* in the National Museum with the name P, Ileirmanni,"' One of these latter sptmens is referred to by Doctor Dall (see Dall, 1818 and 1901) as the type of P. IfeerwnmL This error of Conrad's caused Dall to apply the name 'Ileermanni'' to

The type of P. Meel*i! Connid is in the National Museum (No. 13333) and has been examined by the writer. It, also, is a cctHrlnuH from the bryozoan marl of Santa Barbara. The 'San Raphael Hills,*" from whence the type of 'i! came, according to Conrad, are near Santa Barbara.

P, YfHsoenx! Jay, from Amori, Rikonoken, Japan, .diflfers from P. cnurhivs by having a mon convex shell, wider, lower, more rounded ribs on the right valve, less prominent ribs on the left valve, and by having larger ears, which are truncated more nearly at right angles.

P, caurinuH ranges from the Pliocene upward. It has been reported from the Miocene by several authors, so far none of these records have been authenticated.

Pliocene Pectens. 103

A PecUoi having 19 ribs, and allied to. if not identical with, raurmf/.s was found in the lower Pliocene (i) sandstone at the mouth of tne Raft River, Jetferson County, Wash. The ribs on the right valve of this specimen were narrower and those on the left valve were somewhat higher than those of a typical atKrinuK.

Pecten caurltniM is found abundantly in the lower Pliocene along Eel River, Humboldt County. Some of the specimens from this locality have as many as 25 ribs, and the' ribs are, in some cttses, higher and narrower than in the typical form. On Kel River a))ove the mouth of Price Creek, Mr. J. S. Diller found P, canrSnu associated with the following fauna: uLsff/ris rlchtliofeiu CaUlstu suhdiaphana CliryxodoiiiuH n. sp., Krnnerlln (jrandis K. Inrarlnata Macoiui calcareiu Xatica Piinnimja PJrurofoma percersa Pn'ene n. sp. (?) near om/(>n*nxl}<s .stidrfjl Thravnt trapezoldt'. Trophon near nudtiooatdfus and Yohh'<t sclssurattt. This is a Pliocene fauna.

From Switch Gulch to French Gulch, on the Kel River, P, cnurlnuM is found with the following: Cardimn meekidnunu c/(nmi Mattnt (rf,) callfornica Slliqua patnlii Macotiui calcarta M. Inqnirndd Tape Hiahyt. Tresua nttttalli Solen {of,) hlcariu. Pleurotonia Tlmtrla traptzouh's Chrytiodomus n. sp., Yoldia Hciasurata Pephls (cf,) iantilhi Trophon near inHlticostatus Scutella or Echinarachnlns sp. indet. This is also a Pliocene fauna.

A magnificent specimen of P, caurinus measuring nearly 200 millimeters in altitude, was found by Dr. Stephen Bowers in the Pliocene near Santa Paula, Ventura County.

The type of P, capri/ius is in the LT. S. National Museum, No. 5154.

Living. Puget Sound (Carpenter).

Pleistocene. Santii Barbara; San Pedro (Cooper, Mrs. A. E. Bush, Arnold).

Pliocene. Mouth of Raft River. 7etferson County, Washington (Arnold); above mouth of Price Creek, from Switch Gulch to French Gulch, and south of the middle of Rio Dell Blufi', Eel River (J. S. Diller); Eel River, Humboldt County (W. S. Monroe, A. C. Lawson); T. 1 N., Humboldt meridian, Hui!iboldt County (J. M. Graham); Eagle Piairie, Humboldt County; San Fernando, Los Angeles County (Cooper); Santa Paula, VcMitura County (Bowers, Watts); Santa Barbara; San Pedro (Arnold).

Pecten (Patixopecten) healevi n. sp.

PI. XXXVI, fi's. 1 and la; PI. XXXVll, fij;s. 1, hi, and 2.

1879. Pertni r.rpan:<u. Dall, l*roo. V. S. Nat. Mii... vol. 1, 1S7), p. 14; not IWl,'n rxpaumA Smith,

Quart. Jour. CJeol. Soc, vol. 8, 1847, 41.*, 41U, IS, 11:. 21. 1898. Pecten {Jdtiiopcrteu) Dall, Tnins. \Va;ner Free Inst. Sci., vol. pt. 4, 1898, p. 706,

pi. 2H, Wii. 1.

1903. PccUn [Patiuoperten) e.vjHinsns Dall, Mem. Cal. Acad. Sei., vol. 3, 1903, p. 108.

1904. Pecten expaiiins Dall, Rivers, Bull. So. (-al. Aead. Sei., vol. .3, no. 5, p. (>9.

Desrr/pti'fn. — Shell 180 niilliuieters in altitude, length about equal to height, inequivalve (the riirht slightly more ventricose than the left), equilateral, and with smooth margins; base evenly rounded; sides only slightly

104 Tertiary And Quaternary Pecten8 Ob California.

concave above. Right valve somewhat ventricose, and ornamented by 18 to 21 strong, squarish, subequal primary ribs, which become more or less dichotomous, and sometimes trichotomous, after 30 or 40 millimeters in length; medial sulcus of rib more or less deep, in some cases being as deep as the interspaces near the ends, thus completely dividing the primary rib; interspaces subequal, much narrower than the ribs, quite deeply channeled, and often ornamented by a small, rounded intercalary riblet; whole surface crossed by numerous fine lines of growth; hinge line less than one-half length of disk; anterior ear only slightly longer than left, arcuate in front, and ornamented by several obsolete radial ridges and numerous sharp incremental lines; byssal notch quite prominent; posterior ear slightly obliquely truncated, and ornamented by sharp incremental lines and sometimes by obsolete radiating ridges. Left valve much compressed; ribs narrow and rounded, more or less sharply toward the top (there being in some cases a narrow, slightly raised line along the top); interspaces wide, and each ornamented by a more or less prominent, rounded, intercalary riblet; whole surface striated concentrically by fine, sharp, wavy lines; ears obliquely truncated and sculptured similarly to those of the right valve.

Dltnerisions, — Alt. 112 mm.; long. 112 mm.; hinge line 50 mm.; diameter 18mm.

The measurements are of a specimen somewhat below the average in size. A fine from San Gregorio, San Mateo County, measures 180 mm. in altitude.

The most variable factors in this species seem to be the depth and width of the medial sulci on the ribs of the right valve, and the prominence of the intercalary riblet in the left.

The specimens from San Gregorio and Pescadero, San Mateo County, show, on the average, flatter ribs, more highW developed medial sulci, and intercalary ribs on the left valve that almost equal the primary ones in impoi-tance. Specimens from Purisima and Lobitas, which appear to represent a somewhat lower horizon than the San Gregorio and Pescadero beds, are smaller, slightly more convex, and liave two or three less ribs.

As the forms from both San Diego and San Mateo counties appear to vary through an almost analogous series of mutations, the slight differences enumerated above have not been deemed of even varietal importance. .

A variety of P, liealeyl with 17 ribs is found at Brea Canyon, 4 miles southeast of Newhall, Los Angeles County, associated with the following fauna: Phaandes acutilinatm P. rlchtliofenl Dotiinki ponderona (?), Tritonimn sp., Coum n. sp. (?), sp., Turritella coiypen Tdlina Idm Nevantu recluziarui Trochita Jilosa Chtone near micclncta Cardlutn near corbi JVassa near fossata. This fauna is probably well down in the Plio(!ene.

P, healeyl appears to have a very limited vertical range at the few localities where it is known. In San Mateo County it is found in the Purisima formation, which lies conformably beneath the Merced series, while in San Diego it is very abundant in beds of lower Pliocene age. The great abundance of this species in both the Purisima and San Diego formations may possibly be taken as evidence of their partial contemporaneity.

It was with regret that a name so well established in the paleontological literature of the Pacific coast as P, expatunw was found to })e preoccupied. Since, however,

Pliocene Pecten8. 105

it becomes neoessary to rename the species, it is with pleasure that the writer is enabled to dedicate it to Dr. William Healey Dall.

Pliocene. Purisima to Pescadero, and Punta Ano Nuevo, San Mateo County (J. P. Smith, Arnold); Te mescal Canyon, Santa Monica Mountains, Los Angeles County (Rivers); Pacific Beach, San Dieo Count} (Hemphill, Dall, Arnold, and others); Tia Juana, Mexico (A. W. Greeley); Brea Canyon, 4 miles southeast of Newhall, Los Angeles County (U. S. Nat. Mus.)

PeCTEN (PaTINOPECTEN) PURISIMAENSIS U. sp. PI. XXXIV, tig. H; PI. XXXV, li.us. 1 ami hi.

Description, — Shell averaging about 125 millimeters in altitude, length same as height, valves both equally well compressed, equilateral, and with the margins smooth; base regularly rounded; sides relatively short, straight, sloping at a moderate angle. Right valve with about 24 prominent, T-iail-shaped ribs, flattened and sometimes faintly dichotomous above, overhanging deep, channeled, flatinterspaces, which are about equal in width to the ribs; whole surface of disk with incremental sculpture, which develops into prominent scales on the sides of the ribs; hinge line equal to two fifths length of disk; anterior ear only slightly longer than posterior, sculptured about three prominent radiating ridges and numerous imbricating incremental lines; })yssal notch prominent, but not deep, being equal in width to one-half width of ear; posterior ear obliquely truncated, and ornamented )y about three prominent radiating ribs and imbricating incremental lines. Left valve with narrow, rather sharp, concavesided ribs and wide concave-bottomed interspaces; surface with fine incremental sculpture; ears obliquely truncated and sculptured similar to those of right, except that the radiating ridges are finer and more numerous.

DintertsionH. Alt. 125 mm.; long. 125 mm.: hinge line 50 mm.; diameter 25 mm.

This magnificent species is allied to and df'f/en\ one of which is probably its precursor. is easily distinguishable, however, by the fewer and broader ribs on the right valve, narrower, sharper ribs and broader interspaces on the left, and from by the prominent radial sculpture of the ears.

is characteristic of the Purisima (lower Pliocene) formation, where it is tissociated with heahiiu tnittrr! j/r/nce/jn,, Phaaytdes acutUiHi-atfx Rontelhtrifi ImfKmta etc.

The type is from tlu })eds on the coast north of Pescadero, and is now in the collection of Delos Arnold.

Pliocene (lower). Purisima to and Punta Ano Nuevo, San Mateo County (J. P. Smith; VV. R. Hamilton: Arnold).

106 Tertiary And Quaternary Peotens Of California.

Pkctex (Patinopecen) tuknehi n. sp.

PI. XXXIV, fip. 4; PI. XXXV, tign. 2 and 8.

1888.? Pecien propatulm Cooper, Seventh Ann. Kept. Cal. St. Min., 1888, p. 258 (**Tomale8, Marin County*').

DeHcrlpfion. — Shell averaging about 70 to 80 millimeters in altitude, length same as height, both valves equally compressed, equilateral, and with smooth margins; base regularly rounded; sides nearl}' straight and sloping at a rather low angle. Right valve with eighteen to twenty-two high, narrow, flat-topped, coneavesidod ribs, which, in most crises, a distinct medial sulcus after reaching a length of 30 or 35 interspaces much wider than ribs, round bottomed and sometimes ornamented near the end by a faint intercalary riblet; whole surface of disk finely concentrically striated; hinge line slightly longer than one-half length of disk; ears equal, rectangularly truncated; anterior ear sculptured by four or five prominent radiating ridges and numerous tine incremental lines; byssal notch shallow but distinct; posterior ear with scnilpture similar to anterior. Left valve with narrow rounded ribs, \which are separated by round-bottomed and concave-sided interspaces nuich wider than the ribs; surface sculptured by fine, distinct, wavy, concentric lines; ears as in right valve, except lacking byssal notch. Hinge as in P, ranrunfs,

Duiitnj<!o7Vi. — Alt. 65 mm.; long. H5 mm.; hinge line 35 mm.; diameter 6 mm.

The type is a smaller specimen than the average of this species.

turmi'l is allied to the group of which P, vaunnuH is the commonest representative. Its diagnostic characteristics are its small size for one of this group, narrow, sulcated ribs on right valve and radially striate ears.

Found in the Pliocene at Arroyo San Antonio, near Tomales Bay, Marin County, by Dr. II. W. Turner, late of the United States Geological Survey, after whom it is named.

The type, which is figured, is now in the collection of the department of geology, Leland Stanford Junior University.

Pliocene. Tomales Bay, Marin County (Turner).

Pecten veatchii Gabb.

PI. XL, fijrs. 1 and U.

1869. Peden Veatchii Gabb, Pal. Cal., vol. 2, 1869, p. 32, pi. 10, li'. 50.

1888. Liropecten veaichii Gabb, Cooper, Seventh Ann. Kept. Cal. St. Min., 1888, p. 246.

1898. IWteu Veatchii Gabb, Dall, Trans. Wagner Frec Inst. Sei., vol. 3, pt. 4, 1898, p. 705.

DtHrriptHm, — Shell averaging about 130 millimeters in altitude, slightly broader than high, subequivalve, equilateral, of medium thickness, somewhat ventricose, and with margins finely serrate; base regularly rounded; sides sloping above with slight concavity. Right valve slightly less ventricose than left, with about 8 broad, flat ribs arranged in pairs, and a few small linear ribs on the sides; the

Pliocenk Pectens. 107

whole surface is covered hv several more or less prominent concentric undulations and numerous tine, sciuarisli, imin-icated, raised riblets; hinge line a little more than one-half the length of the disk; anterior ear about one and two-thirds length of posterior, ornamented by about 12 radiating riblets and numerous fine, sharp, imbricating, incremental lines; byssal notch about one-fourth length of ear in depth; ear nuich smaller than anterior, but sculptured in a similar manner. Left valve with about 7 flat, round-cornered ridges of unequal size, which are sepamted bv interspaccvs of unequal width, there being 3 or 5 prominent ribs, between each pair of which is a smaller one; the surface of this valve is sculptured similarly to that of the right, except that the concentric undulations on the ribs IxH-ome more or less prominent nodes toward the apex of the shell; ears similar to those of th( right valve, except that the anterior one has a simple arcuate end and no notch.

/)n/trfis!o7hs. — Alt. 130 mm.; long. 14:5 nun.; hinge line 75 mm.; diameter 50 nun.

This species is (piite similar to and is no doubt the precursor of xuhwdjMu-s, from which it ditfers by attaining a larger size and having fewer and broader ribs. Like the living form, it is cpiite variabh as regards the number and rugosity of its ribs.

The only locality from which this magnificent species has so far been reported is Cerros Island, otf the coast of Lower California, where it is associated with crrroMenslfi P, hvmtri (>Hti\'(i reatdtn and O. orrosen/'s in beds of probable Pliocene age. Doctor Cooper confused one of the large Miocene Pectens (J\ mff(/noh'(f) with this* species when he reported it from the Pliocene of Ojai Valley, Ventura County. (See Seventh Ann. Kept. Cal. St. Min., 1888, p. 246.)

The specimen figured is the type, which is now in the collection of the University of California.

Pliocene. Cerros Island, otl* Lower California (Dr. J. A. \>atch).

Pectkx (Chlamys) baktsciii n. sp. PI. XLI, iiii. 'X

DrserijffioN. — Adult shell averaging about millimeters in altitude, somewhat shorter than high, convex, slightly ineipiilatcral: huso ngularly roinided; margins smooth. Valves with about 40 (more or less unequal) narrow threadlike ornamented on top by mimerous short imbricating spines; interspaces deep, narrow, and channeled; lateral areas rather narrow, perpendicular to disk, and slightly concave. Ears similar to those of /.vAr//7/r//.v.

Alt TrJ mm.; hit. 50 nun.; diameter 28 nun.

This species, of which only two or three rather poorly preserved specimens are known, is quite closely n'latcd to P. opntrfld but is di.Ntinguishable by its nuich larger size when adult, lack of concentric constriction in the later stages of growth, and relatively shorter disk.

P, Imi' is found in beds of probable lower Pliocene age at Crescent City, Cal., where it is associated with Ttrrhrnfalia near hetnpluUi Dall, Phttcoldes

108 Tertiary And Quaternary Pecten8 Of California.

aoutUhuatuH Conmd, and Pecten parmdeei Dall. The type is figured and is now in the U. S. National Museum, No. 164841.

Pliocene (lower). Crescent Citj', Del Norte Count}', Cal., south side of Light-House Point, north of wharf (Diller).

Pecten (Chlamys) bellilamellatus n. sp.

PI. XLI, figH. tta, 7, and

Description, — Shell averaging about IS millimeters in altitude, about as long as high, equivalve, both valves moderately convex, inequilateral; sides nearly straight; margins not serrate. Right valve with 15 or 16 prominent narrow, sharply convex-topped ribs with sloping sides; interspaces uuich wider than ribs, with narrow, flat bottoms; surface sculptured by numerous, regular, equidistant, thin, concentric, imbricating lamella?, which cut squarely across the bottoms of the interspaces, curve convexly toward the umbo on the sides of the ribs, and loop gracefully downward away from the umbo on the tops; hinge line to the length of the disk; ears equal in length; anterior ear convexly truncated, separated from the disk hy a deep, sharply defined, b3'ssal notch, and sculptured by fine, regular, incremental lamellfle and five or six radials; posterior ear acutely pointed, radial}' striate, and with Incremental sculpture similar to but not quite a,s prominent as that of the anterior. Left valve similar to right; anterior ear more prominently sculptured, both radi&Uy and concentricall3', than the posterior.

18 mm.; long. 18 mm.; hinge line IS mm.; diameter 8 mm.; umbonal angle 100.

This species is characterized by its small size when adult, long hinge line, narrow, sharply topped ribs and curved incremental lamellte. It is easily distinguishable from latiaurltus and varieties, with which it is allied, by the above-enumerated characteristics.

P. hellllamellutm is so far known only from the Pliocene at Pacific Beach, San Diego, where it is associated with P, Iwaleyl steaniffu\ etc. Type in the collection of Delos Arnold.

Kance.

Pliocene. Pacific Beach, San Diego County (Arnold).

Pecten (Ciilamys) hastatus Sowerby. PI. XLI, %. 4; PL XUI, fijrs. 1, la, 2, and 2it.

1843. Pecten hastatm Sowerby, Thee. Conch., vol. 1, 1843, 72, pi. 20, tig. 236 (not of Reeve, 1852= P. var. herii'ius Gld.; in part not of Carpenter, 1863; nor of Cooixr, 1888).

1857. Perten altiplectns [typ. err.] Conrad, Pror. Acad. Nat. Sci. Phila., for 1856, Ist ser., vol. 8, ia57, p. 31.3.

1857. Perteu altipllratus Conmd, Pac. K. R. Rept., vol. 7, 1857, p. 191, pi. 3, tig. 2.

1869. Pecten hasUUius Sowerby, Gabb, Pal. Cal., vol. 2, 1869, p. 104.

Pliocene Pectens. ' 109

1887. ?Pecten hcuUatuH Sowerby, Whiteaves, Trans. Roy. Soc. Canada, vol. 4, sec. 4, 1887, p. 119. 1898. Peden hantatm Sower])y, Dall, . Wagner Inst. Sci., vol. 8, 4, 1898, p. 708.

1903. Pecten (Odamys) hantatm Sowerby, Arnold, Mem. Cal. Acad. Sei., vol. 8, 1903, p. 109, 11,

figH. 4, 4a.

1904. Pecten haMatus Sowerby, Keep, West. Am. Shelly, p. 40.

Dtiicrlptimi, — Shell averaging about 64 millimeters in altitude, slightly shorter than high, inequivalve, equilateral (except for ears), compressed and with serrate margins; base evenly- rounded below; sides slightly concave above. Right valve with 9 pairs of narrow, elevated, spiny ribs, along the sides of which are a pair of smaller spiny riblets; major interspaces much wider than ribs, concave -bottomed and ornamented })v 1 or 3 thread-like, spiny, intercalary riblets; whole surface sculptured by microscopic imbricating lines, of which the spines on the ribs and riblets are only modifications : hinge line ecjual to one-half length of disk; ears unequal, the anterior being about two and one-half times the length of the posterior: anterior ear with 7 or s radials and minor riblets, and imbricating incremental lines; byssal notch deep and almost as wide as ear; posterior ear small, and sculptured by lines spiny radials and imbricating incremental lines. Left valve with about narrow, very prominently spiny ribs; interspaces wide, concave- bottomed, and ornamented by a single prominent, central, imbricated riblet, on each side of which are minor thread-like riblets: whole surface of disk with tine incremental sculpture as in right valve; ears similar to those of right valve except that the anterior one has more ribs and riblets and no byssal notch. Hinge with almost ob.olete cardinal crura. Color, golden yellow to pink, the left valve being the darker.

Dliiu'Ufiltnhs, — Alt. nun.; long. iS"! mm.: hinge line 81 mm.: diameter 22 mm.

This beautiful species, which is the southern representative of the group of which var. hfrlrlus is the normal form, is characterized by the great prominence of the spines which adorn the major ribs of both valves. A fossil specimen of this species from th( bryozoan Pliocene marl of Santa Barbara served as Conrad's type of altlpJ lent IIS. (See PI. XLl, tig. 4.)

A variety of P, hasfatti found associated with the typical form in the Pliocene at San Pedro, Santa Barbara, and San Diego, has th( strong' individualized ri))s which characterize the typ(\ but almost completely lacks the prominent spines. The young of this smooth form, and also of the typical spiny form, up to an altitude of about 15 millinuters an* indistinguishable from the young of II! n n /'ti's f/!f/ffn ft'us.

\Vhiteav<\s reports Iiustdfus from Quatsino Sound, British C-olumbia. In

describing his specinicMis. which were collcM-ted by Doctor Dawson, he mentions

the prominent ribs with a singit* row of high spines which characterize this

species.

ha.\(;k.

Living. Quatsino Sound, British Columbia (Dawson, Whiteaves): Montere}' (Button); San Pedro (Oldroyd, Kaymond); Catalina Island (Arnold): San Diego (Raymond). (In all crises

PleistoctMie (lower San Pedro formation). Bath-house Beach, Santa Barbara; Deadman Island, San Pedro (Arnold).

110 Tertiary And Quaternary Pecten8 Of California.

Pliocene. Packard's hill, Santa Barbara (Yates, Wilson, Bowers, and Arnold); Ventiini County (Bowers); Deadman Island, San Pedro (Mrs. A. E. Bush, Voy, Wilson, Oldroyd, Williamson, Arnold, and others); Tenieseal Canyon, Santa Monica Mountains, Los Angeles County (Rivers): Pacific lieach, San Diego (Arnold).

Peien (C'hijmys) HA8TATUR Sowerby var. hericius (would. PI. XLIII, figH. 8 ami

18.5jO. Pecten herichiJ* Gould, '. Bont. Soc. Nat. His., vol. 3, 1850, p. 345.

1852. Pectf*u heririus Gould, Wilkes Expl. vol. 12, 1852, p. 457, fig. 570.

1852. Periea hcuttatm* Reeve (not of Sowerby), Conch. Icon., vol. 8, pi. 11, fig. and sp. 43.

186:. Pecten hastatns (not of Sowerby), Brit. Assn. Kept., 1863, p. (545 (in \y&Tt).

1888. Pecten haMiitm Kiister Kobelt (not of Sowerby, 1843), Conch. -Cab., vol. 17, pt. 2, sp.

210, p. 233, taf. 62, figs. 1 and 2. 1888. Pecten haMatm Cooper (not of Sowerby), Seventh Ann. Cal. St. Min., 1888, 257 (in

part). 1898. J*eaten {Chlamyfi) hericenn Gould, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898,

p. 708.

1903. Pecten (Chlamys) hericenn Gould, Arnold, Mem. Cal. Acad. Sci., vol. 3, 190:, i>. 110, pi. 11,

fig. 2.

1904. Pectm herireus Gouhl, Keep, West. Am. Shells, pp. 3t>-40, fig. 19.

Dtm'rljdlon, — Adult shell averaging about 70 millimeters in altitude, not (quite as long as high, both valves compressed, equilateral (except for ears), which are decidedly unecpial; margins finely sermte; sides markedly concave above; umlx) acute. Right valve with 9 or 10 pairs of spiny fasciculi, the middle rib of each fascicule being the most prominent; interstices about as wide as the fasciculi, and oinanunted by seveml more or less spiny ri))lets; spaces the riblets of the fasci(!uli and large interspaces channeled and ornamented by line imbricating incremental lines, but free from any reticulations whatever: hinge line a little over one-half the length of the disk; anterior ear about two and one-half times longer than the posterior, ornamented bv imbricating concentric lines, and above the notch several subeipial spiny riblets; byssal notch wide and deep; posterior ear small, and ornamented by numerous line spiny riblets. Left valve with about 1) or 10 elevated fasciculi, the middle rib of each fascicule being quite prominently spinose; the spaces between the major fasciculi each occupied b}' a minor fascicule of more or less scaly riblets; interspaces the riblets channeled and with imbricating incremental sculpture; ears sculptured as in right valve except that the riblets are smaller and more luimerous on the anterior ear. Hinge weak}- developed. Color pink to greenisli, left valve the darker.

Dimennumjt. — Alt. 78 mm.; long. 65 nun.; hinge line 34 mm.; diameter 21 mm.

This variet}' appears to be the normal form of the group of /tastatuM the typical hamtntuJi having the imbricating spines on .the ribs extremely developed. The only difference between and this variety is in the relative prominence and abundance of the ribs and riblets forming the fasciculi. In the right valve of the adult var. each fascicule consists of three nearly spiny

PLIOCENE PECTENS. Ill

riblets (the middle riblet of the three -being slightly more prominent and spiny), between which and the middle riblet of the adjoining interspace are two small riblets (and sometimes another still smaller pair of intercalaries), while in the adult P, hastatua the fascicular arrangement on the right valve is obscure, there being a central spiny rib with 2 and sometimes 4 faint scaly riblets between the major rib and the middle riblet of the interspace. The ftisciculi of the left valve of licnrlus are convex, and consist of a central more or less spiny rib, between which and the middle riblet of the fascicule of the intrspa(;e are about 9 to 12 thread-like scaly riblets; while in ha.tafuH there is a high narrow rib with steeply sloping sides, having a top ornamented by numerous tall curved spines; between this rib and the rib running down the interspace are from three to live faint thread-like scah- riblets.

var. hertchui ranges from the Miocene (Santa Margarita formation) to the Recent fauna. The fossil forms average smaller, and appear to have slightly more scaly secondary riblets, but in all other respects they are identical with the living shells.

A single specimen of Peden closely allied to if not identical with P. var. hericiicx was found associated with P, tstrtlUDiHs Conrad, Osfrea palmuJa Cpr., Tamiosoma (jregarla Conrad, Chorus helclier! Hinds, and AHtrodapsiH tumiduH Rmond, ner San Lucas, Monteny County.

The type of P, hertclu'S is from the Strait of Juan de Fuca, off the north coast of Washington, and is now in the V , S. National Museum (No. 5955).

Living. Puget Sound (Dall, Carpenter, Button).

Pleistocene (lower San Pedro formation). Deadman Island, San Pedro (Arnold).

Pliocene. Temescal Can3on, Santii Monica Mountains, Los Angeles County

(Rivers); Deadman Island, San Pedro (Vo}*, Arnold); Pacific Beach, San

Diego (Hemphill, Arnold). Miocene (upper). San Lucas, Monterey County (Hamlin, Arnold).

Pecten (Chlamys) hastatus Sowerby var. hindsii Carpenter.

PI. XLIII, tigs. 1, 2,

Pecten haMutus (? var.) hinchil Carpenter, Brit. Assn. Rept., 18(>8, p. 645.

1887. Pecten herirewH var. hindsii Carj)€nter, Whiteaves, Trans. Roy. 8oc. Canada, vol. 4, sec. 4, 1887,

p. 119. 1898. Pecten Iwricea var. hindsii Car[>enter, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898,

p. 709.

Deacription, -Shell smaller than P. var. her let ws averaging about 58 millimeters in altitude; shape and convexity as in var. herK-lus; margins smooth. Right valve with about 26 close-set, sometimes wide, tlattish, usually dichotomous, smooth ribs, which show line lines of growth on their surface; interspaces narrow, channeled, 'and 8cultured minute reticulations; hinge line one-half as long as disk; anterior ear produced, sculptured by about six radials and prominently imbricating concentric

112 Tertiary And Quaternary Pectens Of California.

lines; byssal noU*h prominent; posterior ear *snail and witli radials and imbricating concentric sculpture. Left valve with small, obscurely fasciculated, imbricated ribs, each fascicule having one major and several much smaller and more prominently imbricated riblets; interspaces very narrow and sculptured as in right valve; ears similar to those of right valve except lacking notch in anterior one. Color pink to white, the left valve the darker.

DlrntiiHions, — Alt. 58 mm.; long. 57 mm.; hinge line 29 mm.; diameter 18 mm.

Doctor Dall, in mentioning this variety, says:'' 'The typical specimens seem remarkably distinct from hericeus var. mi rtirvhui* but in a large series intergradation is obvious.'" Carpenter in his original description mentions that var. ! passes from toward txlaudlcuff,'''

Living. Bering Sea to Monterey (Dall); Victoria, B. C. (Button): Quatsino Sound

and vicinity of Vancouver Island (Dawson; Whiteaves). Pleistocene. Sucia Island, Puget Sound (Newcombe). Pliocene. Deadman Island, near San Pedro (Arnold).

Pectex hastatus Sowerbv var. navarchus Dall.

PI. XLIIl, fijp*. 1, 1, and \h.

1S44. Pecten rubidui* Hinds, Zool. Voy. Sulph., lvS44, 61, pi. 17, fig. 5 (not P. rubidus Martyn,

1784). 1898. Perteii hericeim var. mirarrhm Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 708. 1904. Pecten rubififm Hinds, Keep, West Am. Shells, p. 40.

DeHcnption. — Shell averaging about 55 millimeters in altitude, higher than long, both valves only slightl}' ventricose, thin, sides only slightU* concave above. Right valve light colored, less ventricose than left, with numerous small, subangular, flat-topped, dichotomous, and slightly imbricated ribs; surface obscurely tessellated; anterior ear quite prominent, with about 6 prominent radiating ridges and numerous imbricating incremental lines; byssal notch of medium size; ear small, with distinct radial ridges and imbricating sculpture. Ijeft valve reddish or phikish, more ventricose than right, with numerous small fasciculated and quite prominently imbricated ribs, each fascicule having one prominent rib in the middle with lesser ones on the sides; the major occupied by a small riblet; ears as in right valve except lacking b'ssal notch. Margins not prominently sermte.

Diineniunm, — Alt. 55.5 mm.; long. 54: mm.; hinge line 21 mm.: diameter 17 mm.

This variety is smaller and more delicate than P, isUnuitruif and has fasciculated rather than dichotomous ribs on the left valve.

Living. Aleutian Islands southward to California (Dall): Kodiak Island, Alaska ((Ireeley and Snodgrass).

o op. nit., p. 709.

o

Pliocene Pectens. 113

Pleistocene. Bowlder clay of Coiuox, Vancouver Island (Newsom])e). Pliocene. Deadnian Island, San Pedro (Dall, Stearns); Timnis Point, San Pedro (Arnold); Pacific Beach, San Diejjo (Hamlin).

PkCTEN (('llLAMYS) IIASTATIS SoWEUBY Var. STHATECJUS Dall. PI. XLIV, 2, 2r/, .S, and 4.

1898. IWfen hericens var. Rtrateyusi Dall, Trans. Wagner Free . Sci., vol. 3, 4, 1898, p. 709 1908. IWten (Chlawifs) serious var. Dall, Arnold, Mem. Cal. Acad. Sei., vol. .S, 1903, p. 110, pi. 11. lig. 5 (right valve of a yonng .peeinien

—Adult shell averaging about 85 niillimeters in altitude, slightly hightM' than long, inc(|uivalve, equilateral, except for ears; both valves nearly flat up to an altitude of about ii2 niillimeters, where they genenilly become more convex by contmction, and the sculpture more complicated. Right valve with 9 to 12 prominent, subcHual. broad, ncirly flat-topped, usually dichotomous, turgid ribs, with sometimes smaller intercalaiy riblets, all of which break up more or less suddenly into fasciculi of two or more riblets upon reaching an altitude of about 22 millimeters; interspaces subecpial, broad, and channeled; whole surface of disk and ribs microscopically tessellated; hinge line equal to about one-half length of disk; anterior ear nuich produced, and sculptured by flne imbricating incremental lines and about H radial ridges; byssal notch prominent; posterior ear nearly ob.solete, sculptured similarly to right. Left valve resembling the right except that the ribs are narrower, more convex, and with the intenalary riblets usually more interspaces broader than in right valve; anterior ear with about s imbricated ridges. Color of recent specimens bright scarlet.

— Alt. 35 mm.; long. 84 mm.; hinge line 17 mm.; diameter 16 mm.; umbonal angle 83 mm.

This variety is easily distinguished b}' its few broad ribs, which increase in number rapidly both by division and int(*rcalation after reaching an altitude of about 20 millimeters. Some of the Pleistocene (lower San Pedro formation) specimens from San Pedro retain a pinkish color.

Living. Tnalaska (Dall).

Pleistoc<*ne. Alaska (Dall); Deadman Island, San Pedro (Arnold); Bath-house

Bimch, Santa Barbam (Arnold). Pliocene. Packards Hill, Santa Barbara (J. H. Wilson).

Pectten (CyHLAMYs) isLANDicus Mi'iller. PI. \LV. tig.. I an.l in.

177G. O.S/ Is/aufllcns Midler, Prodr. Zool. Dan., No. 2990, p. 248.

1778. Pnini Born, Mu.., p. lOli. Fifh- Dall, 189S.")

1780. Odrea hlandirn Midler, FabrieiuH, Fauna (grind., p. 415.

1784. Pi'cU'n Idnmlicnx Midler, Chemnitz, C\>neh., vol. 7, p. .S04, ♦io, tigs. JilT) and

1784. Pectt:n rnhidnn Martyn, Univ. C'oneh., vol. 2, pi. 15o, tig. 1.

1797. Ostivn thmiHsa Musenin C'olonniannni, p. 52. No. 98t).

No. 47— (Hi 8

114 Tertiary And Quaternary Pectens Of Oalifornia.

1831. Pexten Pmlei Conrad, Ainer. Mar. Conch., p. 12, pi. 2, fig. 2.

1836. Pedeii hlandka MuUer, Lamarck, Anim. Sans. Vert., ed. 2, vol. 7, p. 145, No. 42.

1843. Pecten IsUitvlifus Muller, Sowerby, Thee. Conch., vol. 1, Pecten. figs. 159-161.

1844. Pecten 'd Philippi, Abbild. Beschreib. C<)nchyl., vol. 1, p. 101, pi. 1, tig. 5. 1853. Pecteii hUmdiaui Muller, G. O. Sars, Moll. Reg. Arctiav Norveghe, p. 16, pi. 2, tig. 2.

1888. Pecteii islandinis Muller, Kusterand Kobelt, Conch.-Cab., vol. 17, pt. 2, Spondylup nnd Pecten,

No. 24, p. 59, taf. 16, tign. 1 and 2. 1888. Pectin ulandicus Chemnitz, Kiister and Kobelt, op. cit., p. 105, taf. 30, tign. 1-6. 1888. Not Pecten Cooper, Seventh Ann. Kept. Cal. St. Min., 18H8, 257 (=7'. jordan

Arnold, 1903).

1897. CfUamys iitlandica (Chemn. ), Verrill, Trans, ('onn. Aci. S<*i., vol. 10, June July, 1897, p.

72, pi. 16, figs. 2-5/>; pi. 20, fig. 9; pi. 21, fig. 2.

1898. Pecten (Chlamys) ialandicus Muller, Dall, Trans. Wagner Free Inst. S'i., vol. 3, pt. 4, p. 708. 1901. Pecten islandieus Muller, Bn*)gger, Norges Geol. No. 31, p. 228, fig. 23, tab. 5, figs.

1, a, by r, and d.

Deacripticm, — Shell averaging about 80 millimeters in altitude, subcircular, somewhat higher than long, subequivalve, both valves only slightly convex, equilateral, except for ears; of medium thickness; sides only slightly concave above; base evenly rounded; color of liWng shell pinkish to salmon, the left valve being the more highly colored. Right valve with numerous narrow, square, flat-topped, imbricated ridges, which multiply slowly, by division and intercalation, as the shell grows; interspaces narrow, channeled, and minutely reticulated; hinge line equal to more than one-half length of disk; anterior ear much produced, sculptured by numerous sharp imbricating lines and 5 or major radiating ridges and some intercalaries; b3ssal notch quite prominent; posterior ear a little over onehalf as long as the anterior, and sculptured in the same way. Left valve similar to right, except possibly that the imbrication is a little more pronounced.

Dimensl/niH, — Alt. 83 mm.; long. 77 mm.; hinge line 44 mm.; diameter 27 mm.; apical angle 84.

This species is characterized by its large size when adult, large number of subequal scaly ribs, reticulated, channeled interspaces, and the relatively long posterior ear for a member of this group.

Only two authentic specimens of this species are known from California; are from the Pliocene of Deadman Island, San Pedro, one being in the Voy collection at the University of California and the other in the collection of Delos Arnold.

Living. North Atlantic; Bering Sea (Dall).

Pleistocene. Bowlder clays of the northwest American coast, Alaska, and british

Columbia (Dall). Pliocene. Deadman Island, San Pedro (Voy, Arnold).

Pkctex (Chlamys) .tordani Arnold.

PL XLIV, figH. 1, \a, and \h.

1903. Pecten {(1tlam!fi<) Jordan i Arnold, Mimu. Cal. Acad. Sci., vol. 3, 1903, p. Ill, pi. 12, figs. 6 and 7.

DeJtcriptfo?!, — Shell shape of P, /.sAr//<//V'//.v, averaging about 45 millimeters in altitude, somewhat shorter than high, inequivalve, both valves convex, equilateral

Pliocene Pectens. 115

except for ears, rather thin, and with smooth margins. Right valve with about 25 to 30 angular smootli-topped, imbricated rib.s, which become dichotomous after reaching a length of about 30 millimeters; interspaces deeply channeled and narrower than ribs; anterior ear imperfect radially ribbed with ridges, and showing elevated, concentric incremental lines; posterior ear nearly obsolete, showing about 4 ribs; byssal notch not deep. I-Kft valve with 25 to 30 narrow, convex ribs, showing imbricating sculpture onh' slightly; interspaces as wide as or wider than ribs; after a diameter of 30 millimeters has been reached by the left valve small intercalar}' ribs appear in most of the widening interspaces; anterior ear with 5 narrow, imbricated ridges separated by wide interspaces. Both valves show a tendency to contract suddenly at the basal margin upon nearing completion of growth; surface of both valves covered with a minute lattice-like sculpture, which is generally worn otf on exposed portions of the shell.

— Alt. 45 mm.; long. 42 mm.; hinge line IS mm.; diameter 15 mm.

This species is allied to the group of which lhtHdicu is the type. Although separated from the other members of the group, it is, nevertheless, quiti closely related to /latatu var. ffffrarc/ius and var. hhifhU. The right valves of jonhuii and of the two varietitvs above mentioned are very similar, but the left valve of P, Jordan! is entirely different from that of the other two, having simple, lattice-like sculptured ribs instead of imbricated, fasciculated ones. P,jonhini is distinguishable from luoitatnH and the latter's variety herimuH by its lack of fasciculated ribs. No gnidation between I Jordan! and other members of the group has been noticed by the writer, whereas in nearly all the other cases a large shows obvious intergradation between the different forms.

P, Jordan t is found in the Pliocene and lower Pleistocene, but is not known as living.

Pleistocene (lower San Pedro formation). Deadman Island, San Pedro; Santa

Barbara (Arnold). Pliocene. Deadman Island, San Pedro (Bush, Wilson, Oldroyd, Arnold); Santa

Barbara; Pacific Beach, San Diego (Arnold).

PI. XLVI, tiers. 1', L'fi, ;], and Wn.

1H87. I'erten fatianritus (Vmrad, Jour. Nat. S'i. Pliila., vol. 7, ls;>7, 2.SS, pi. IS, 9 1842. Pfi-tcii latKini'dtHs Conrad, Sower))y, Thes. Condi., vol. 1, pt. 1, 1S4', ])I. J2, 1\\tii.

20, 21. 1844-1847. tfunai Philipju, 1844; - 7'. ,n*i,timenH Sowerby, 1847 (Ji'U- Dall, lsW). 1852. Pecten latlnunttn* Conrad, Reeve, Conch. Icon., vol. 8, 1852, pi. 1, ti. 5. 1863. Perten Idtianritnn Conrad, Carpenter, Brit. Asnn. Re[)t., 18H8, p. 645. 1888. Perten Ititiauntnx Conrad, Kiister and Kobelt, Con(;h.-Cab., vol. 17, pt. 2, SjMmdylus und

Peoten, No. 168, p. 203, taf. 54, 6j:s. 7 and 8. 1888. Pa-ten hitkwrituH Conrad, Coojyer, Seventh Ann. Kept. Cal. St. Min., 1888, 257. 1892. PecJen latiauritny Conrad, Keep, Wegt Coant Shell.', 1892, p. 167.

llfi TKRTIARY AND QUATERNARY PECTENS OF CALIFORNIA.

1892. Peden Inttauritus Conrad, Williamson, Proc. U. 8. Nat. Mus., vol. 15, 1S92. p. 198. 1898. Pertm {(hlaniii) fafianriluit Conrad, Dall, Trans. Wagner Free Inst. Stri., vol. 3, pt. 4, 1898, p. 709.

1903. Pecten {ChlamnH) hiikiuritvs Conrad, Arnold, Mem. Cal. Acad. Sci., vol. 3, pt, 2, 1903, j).

Ill, pi. 12, figs. 2 and 2a.

1904. Perten Intiauritm Conrad, Keep, Wist Am. Shells, p. 40.

— Shell averaging about 25 millimeters in altitude, about as long as high, inecjuivalve, compressed, inequilatenil, disk obliquely produced postriorilvj thin; sides straight; margins smooth. Riglit valve more compressed than left, with 12 to It) low. mther squarish ribs, separated by ecjual, more or less distinctly channeled interapaces; whole surface sculptured by numerous line concentric lines; hinge line nearly as long as disk; ears subequal in length; anterior ear long and narrow, with 5 or 6 prominent dials and numerous tine concentric lines; byssal notch deep and distinctly separating (ar from disk; posterior ear from rectangularly to acutely pointed, sculptured ])v obsolete radials and concentric lines. Left valve somewhat more convex than right, otherwise similar to it; anterior ear generally shorter and more prominently sculptured than posterior.

— Alt. 25 mm.; long. 23 mm.; hinge line 20 mm.; diameter 9 mm.; umbonal angle Uo .

This species is characterized by its small size, oldique disk, thinness, long hinge line, and deep byssal notch. The sculpture of the shell is usually well marked. Th( ribs are sometimes faintly medially sulcated, and the interspaces souKtimes contain a faint intercalary riblet in the later stages of growth. The Pleistocene shells, as a rule, are rather more strong' than the living.

A pair of valves in the U. S. National Museum (No. from U. S. Fish Commission Station No. 2840, Santa Barbara Islands, is labeled fnnih'Zi'nHiii Orb." This shell is proba]>ly an albino variety of luf!(niritn. having just a touch of color on the interior of the posterior ear of the left valve. The true tntuhrzenKlfi is from the Ieruvian part of the South American coasts.

In the Third street tunnel, Los Angeles, latlatrrltu has been found associated with the following fauna: IWtrn jtetlt'oama opuntht P, HteHVihs!! (rltiphtH dnHuiatkrattu SnaHti n. sp. Macoma sp. indet.. Area mitlttvoHtdtn Linui hamUni liuceinnm. h[). indet., Neierha vtchiziana Astarf* sp., Prienr (htren veatch!t\ Plenrotonai sp. indet., and a carditoid. As this fauna indicates a horizon well down in the Pliocene, it extends the geologic i-ange of P, much further back than heretofore known.

/'. Iattaur!ttis is found living attached to kelp, those specimens inhabiting the deeper, quieter waters being less strongly sculptured than those which are subjected to a more strenuous existence nearer the shore.

Living. Monterey (Yates); Santa Barbara to San Diego (Carpenter and others). Pleistocene. Santi Barbara; San Pedro (Cooper); San Pedro; San Diego (Arnold,

Wilson, Dall). Pliocene. Third street tunnel, Los Angeles (Hamlin).

Pliocene Pecten8. 117

Pecten (Chlamys) lawson n. sp. PI. XLV, %.s. .Jand 4.

DtHi-riptlon. — Adult shell about 70 millimeters in altitude, not as long as high, inequi valve, only slightly convex, ecjuilateral, ears untMiual; hise regularly rounded; sides only slightly concave above; margins somewhat serrate. Right valve with about 18 to '20 prominent, narrow, round-topped, rugose ridges, separated by somewhat wider interspaces, in each of which runs a single more or les8 rugose riblet; some of the ribs are occasionally medially sulcated or dichotomous; surface sculptured by numerous irregular incremental lines, which give the ribs a squamose appearance when they are unworn; ears unequal, the anterior with three or four rather rugose radials and munerous incremental lines; the posterior with several less prominent radials, and incremental sculpture; byssal notch rather profound. Left valve with 9 or lo prominent narrow, round-topped, rugose major ribs, between each two of which then* is a single minor rib similar to and almost etpialing in prominence the* major ribs; a single thread-like intercalarv is visible in most of the interspaces; surface sculptured as in the right valve; eirs similar to those of right valve except that there is no prominent notch between the anterior one and the disk.

Dliiwnsinns. — Alt. 70 nun. ; long. SI mm.; diameter 24 nun.; umbonal angle 87-".

This species is closely allied to /ta.sfaftf.s. but is distinguishable by the paucity of its secondary sculpture (such as spines and secondaiT intercalaries), the nearh' e<]ual prominence* of the major and minor ribs in the left valve, and the eijuality of tin* interspaces in the right. (The ribs in the right valve of hastatui< occur in pairs, each pair being separated from those adjacent spaces ])erceptibly wider than the interspaces between the members of each pair.) The smooth variet}' of /{(.s mentioned as occurring in the Pliocene at San Diego, San (iregorio, etc., appears to occupy a position about midway betweiMi the typical hnsfiftni< and hnrsoni.

The type of P, hursinu which is now in collection of the California Academy of Sciences, was colhctcnl Mr. F. M. Anderson from the Pliocene at the Waldorf asphalt mine, 4 miles south of Guadaloupe, Santa Barbara C'ounty. Mr. Anderson has kindly furnished th( following list of fossils from the beds at this mine: Crepidiila jprhurpM /hi coop r i Ti'/fitn/i ((.//// (iabb, Prleue ovrf/oth Hs/s KilHeld, Irochittt i'ttstelhifn C'onrad, Lniuii'm UtrisiJ (lould, Xatica sp., (/(//tf/f if /f/ffN/f sp,, perphtijti'is Hinds, PJrtirofoma near <v//yA ///r/'/V//// (labb, Ph nrottniKi near frf/nninnaATVihh Pi/rnla (i) sp., DrUUa />/v>.v/ CarpcMiter. lin'jmni cr/sprifa (uhdithrlla ruhtlutfi nl Ciabb. Dentaliunt sp., Arncf'tt sp., (jrh' Ciould, Lrdu taphrhi Dall, Arcn 2 sp.. Wnrrimrdia rditrfmsd (rould, linuhtra .sYv/y>//// (iabb, 7) 11 Jim sp., Jcfih "2 sp., JLf/'ffsia tn'oldes (jould, Plun-nKhs Lurnm) near (onrad, Phm-oUlis sp., Marmmiip. J/f/f/'/, 0,sfrra sp.. hrhituirachnhfs sp, and coral.

The writer is also indebted to Mr. Anderson for the following list of fossils from a locality I mile north of Schumann 'h, (8 miles east of the Waldorf asphalt mine), Santa Barbara C-ounty: Trorhlta rnar rontMata Conrad, Troehitd near

118 Tertiary And Quaternary Pectens Of California.

Gabb, CallloHtoma sp., Lun/itia hwixi! Gould, (r7t/cf///if'r!i< Pert tmculuH) near patulm Conrad, Glycijnu*rls sp., Venfricnrdh t'tntncoxa Gould, Pt-vUi lattsofii- n. sp., Pecten aMryl n. sp., etc.

Named in honor of Dr. A. C. Lawson, professor of geology at th( University of California.

Plioc'one (lower). Waldorf asphalt mine, 4 miles south of Guadaloupe, and I mile north of Schumann switch, Santa Barbara County (F. M. Anderson).

Pect'en (Ciilamys) oruNTiA Dall.

Pi. Xli, 2.

1898. Pedeii [Chimnf/s) opwitia Dall, Trans. Wagner Free Innt. Sci., vol. .S, pt. 4, 1898, p. 707, pi. 29,

1903. Pecten {('hhmi/i*) opnntia Dall, Arnold, Mem. (al. Aitad. Sii., vol. 3, 1898, p. 118.

DtHrriptlon, — Shell averaging 85 millimeters in altitude, slightly shorter than high, subequivalve, equilateral (except for ears), ])oth valves nearly flat until altitude of about 10 to ti5 millimeters is reached, when the}" grow more convex; contracted at basal margin when adult; sides only slightly concave above. Right valve with 40 to HO subequal, narrow, imbricated, more or less dichotomous ribs, which are separated by channeled interspaces about equal in width to the ribs; hinge line about two-fifths as long as disk; anterior ear much produced, sculptured by a])out six prominent, sharp' imbricated radials, and imbricating incremental lines; })yssal notch ciuite prominent; posterior ear nearly obsolete, radially and concentrically sculptured; whole surface of disk and ears sometimes microscopicallv checkered or tessellated. Left valve similar to right.

I)! int nylons, — Alt. 48 mm.; long. 40 mm.; hinge line UJ mm.; diameter 12 mm.; mnbonal angle 78 .

This species is allied to P, luiHtatuH var. mtvarchiis from which it differs by its smaller and not fasciculated radial ribs, more elongated anterior ear, more densely radially costate posterior ear, small size when adult, and b}' a tendency to be suddenly contracted at th(* basal margin on the completion of growth. opuntm is distinguishable from other members of this gi'oup by its large number of nearly eciual thread-like and small umbonal angle.

Pliocene. Pacific Beach, San Diego (Hemphill; Hamlin; Arnold); Packard's Hill, Santa Barbara (J. H. Wilson, Arnold); Rincon Creek. Santa Barbara County (Watts); Third Street tunnel, Los Angeles (Hamlin): Temescil Canyon, Santa Monicii Mountains, Los Angeles County (Rivers).

Pliocene Pegtens. 119

Pecten (Chijvmys) Parmklkei Dall.

PI. XLI, fi. 1, la, o, and ba.

1898. Pecten {CJUamys) Pnrmeleei Dall, Traiif?. Wagner Free Inst. Sci., vol. 3, pt. 4, p. 708, pi. 37, fipj. 14 and 14,

DtHcrlptifHt, — Shell aveming about 50 millimeters in altitude, somewhat shorter than high, rather inequivalve, equilateral; ears unequal. Left valve with 5 prominent, narrow, smooth, and convex-topped ribs, sepamted by much wider interspaces which are sculptured numerous, rather tine, radial riblets; whole surface of disk covered by profuse, coalescent, microscopically checkered sciuamation; anterior ear produced and ornamented by several small i*dials and microscopic sculpture; posterior ear short, but otherwise as anterior. Right valve similar to the left, except that the ribs, which in the right valve correspond to the interspaces of the left, are much broader than those of the left; interspaces relatively narrower. The disks of both valves are constricted at irregular intervals, which tends to give the ribs a nodose appearance.

DimenilothH, — Alt. 45 mm.; long. 38 mm.

This species is close to Bernhardi, of Japan, but smaller, and differs by the smooth top surface of the ribs, which in sfiuftil are more or less striated or coai*sely threaded, and by the not alternated radial riblets on the left anterior ear; also, especially, the peculiar microscopic squamation which makes a complete external coating to the valve. yM77//e/t?c/ differs from P. nattsl by it narrower ri])s on the left valve, liner radials in the interspaces, less prominent constrictions of the disk, and peculiar microscopic sculpture.

Only two specimens of this species have so far been found: a left valve (the type, U. S. N. M. 1544710 from the Pliocene at Pacific Beach, near San Diego, and an imperfect right valve (l". S. N. M. IG4842) from the Pliocene at Crescent City, Cal.

Pliocene. Crescent City, Del Norte County, south side of Ligiit-House Point, north of wharf (Diller); Pacific Beach, San Diego

PeCTEK (CiILAMYS) WASTIBl KNEl 11. Sp.

IM. XLV, fig. 2.

Demn /)t ion. -iiheW avemging over loo millimeters in altitude, somewliat shorter than high, sulieciuivalve, equilateral (except for the ears), rather thin; base regularly rounded; sidivs somewhat concave above. Left valve with about 6i> more or less luuMiual. faintly low, squarish ribs; interspaces about as wide as the ribs, and somethnes ornamented by an intercalary thread or riblet; whole surface of disk ornamented by imbriaitiiig lamella*; anterior ear somewhat convex in front, and with a faint suggestion of a notch, sculptured by about 12 rather low imbricated radials; posterior (ar about one-half as long as the anterior, obliquely truncated, and ornamented by faint radials and imbricating lamella*.

120 Tertiary And Quaternary Pectens Of C'Alifornta.

Rijifht valve unknown, but, judging ])v the afiinity which this species bears to inhintlirKs it should be similar to the left valve, with the exception that the anterior ear should have a deep bvssjil notch, and the ribs should be slightly broader and the interspaces correspondingly narrower.

DhiieihHitfHs, — Alt. 110 mm.; long, about lOo mm.; hinge line about 50 mm.: diameter 80 mm.

This siKicies is closelv allied to and may be it direct precursor. It is distinguishable from the latter, however, by its larger size (being the largest species of this group yet known from the Pacific coast), more numerous, lower, and smoother ribs, and less o])liquely posterior ears.

P. occurs in beds on the Yachates River, Lincoln County, Oreg., where it is associated with the following fauna: Opal la Dall, IWehratella tratiiireriia Sby, Acffueu sp., Stroifgyloccntrotui* {cf,) Stimpson, drlaris sp., Xatica or NfVtrlta sp., IhicTunnn sp., CalHoHtoma sp. Doctor Dall is of th( opinion that these beds are the equivalent of those at Eugene, Greg., of whose position in the stratigraphic column there is much uncertainty. Tentatively, however, this species will be placed with those from the lower Pliocene.

This species is named in honor of Mr. Chester Washburne, of Eugene, Oreg., whose work in the Oiegon Tertiary has added many new species to the lists. The type is now in the V , S. National Museum (No. 3593.

Pliocene (lower Yachates River, Lincoln County, Oreg. (Washburne).

PeCTEN (ChLAMYs) WATTSl U. sp. PI. XI, fig8. 1 and ht.

Desci'lptinn, — Shell averaging about ()5 millimeters in altitude, slight' higher than long, equilateral, of medium thickness, decidedly ventricose, and with margins slightly finely serrate; base regularly rounded; sides sloping above, with slight concavity. Left valve with 5 high, rather narrow, rounded, almost smooth ribs, which are made prominently nodose by several very pronounced concentric undulations, or constrictions; interspaces wider than ribs and each ornamented by about 5 small, subequal, rounded, imbricated riblets; whole surface of disk with a profuse, coalescent, microscopically checkered squamation; hinge line about twofifths length of disk; anterior ear with arcuate end, and with surface sculptured by about 5 prominent riblets and several concentric undulations; posterior ear obsolete. Right valve about ecpial to left in convexity, with broad, flat-topped ribs and narrower interspaces, both being longitudinally sculptured by subequal riblets; ears similar to left; byssal notch not prominent; surface sculpture microscopic; constrictions less pronounced than in left valves.

DhnenUms, — Alt. 67 mm.; long. 59 mm.; hinge line 20 mm.; diameter 36 mm.

This species is even more close' allied to naclftU Bernhardi (Jour, de Conch., vol. 7, 1858, p. 90, pis. i and ii), of Japan, than is jmrmdeeL It is distinguishable from inciftll however, by its broader ribs, not alternated radial riblets on the right anterior ear, and by the smaller number of secondary

Pliocene Pectens. 121

nblets ill the wide interspace!. The specimens of P, vHitts! are too poorly prerved to show satisfactorily the niitioscopic sculpture of the surface, but what is left of this sculpture appears to veiy much like that of /iL

tratUi differs from parmehe! in having liroadei* and more strongly nodose ribs, more numerous (6 instead of 4) radials on the anterior ear, and most of all by the fewer and much larger-sized secondary radial in the major interspaces. Th( poor state of preservation of the type of tvattsi precludes any definite statements regarding its microscopic surface scul})ture, but from as good a comparison as could be made under the circumstances the two species appear to have somewhat diti'( kinds.

inatts! is found in beds near Kreycnhageirs ranch, County, which are supposed to be of lower Pliocene age. It has been collected from beds of lower Pliocene age (Purisima formation) on Pescadero Creek, San Mateo County, and at other localities in the southern part of the State. At Olinda, Puente Hills, Orange County, Mr. Eld ridge found fn/ff.ii associated with (fxh/ci/i, riuiiu Nfrcrita Jhamiihfs ca/iffprnicK-s and (cf.) harharenis in beds of probable lower Pliocene age.

The type is from Kreyenhagen's ranch, Fresno County, and is now in the collection of the California Academy of Sciences. It is named in honor of Mr. W. L. Watts, whose collecting has added very to the list of west coast fossil Pectens.

Pliocent* (lower). Pescadero Creek, one-fourth mile above Jones Cxulch, San Mateo County (Newsom; Arnold); Kreyenhagen's ranch, Fresno County (Watts); Olinda, Puente Hills. Orange County (fcldridge).

Pecten (Chlamys) watts var. mouani n. var.

1*1. X, tigs, o, 4, o, ami

Description. — Adult shell averaging millimeters in altitude, nuich shorter than high, intHjuivalve, ecjuilateral, moderately convex, and with slightly serrate margins. Right valve less convex than the left, ornamented 4 very broad, ])rominent, flat-topped ridges, each of which carries from 5 to 7 strong, elevated, interspaces narrow and rather deep, each ornamented by I or 2 scjuarish riblets; hinge line about one-third length of disk; anterior ear mon* ])roniinent than the posterior, regularly arcuate-ended and sculptured by oi* tJ radials; byssal notch only slightly developed; posterior ear very short, obliquely truncated and radially striate. Left valve more convex than right, and usually more or uiidulated by constrictions; disk with 5 subequal, narrow, ridge-like separated by wide interspaces, in cmcli of which are from 2 to 5 subequal, prominent, scjuarish whole surface ornamented by a superimposed which is usually worn off in the adult shells; ears similar to those of the right valve, thei-e nearly as pronounced a byssal notch in the anterior ear of the left valve as in the anterior one of the right.

122 Tertiary And Quaternary Pectens Of California.

DhnenHtonH. — Alt. (>4 mm.; long. 58 mm.; hinge line IH mm.; diameter, right valve 10 mm.; left valve 13 mm.

This variety is similar to the typical mitth except that it is somewhat less convex and less constricted, and, as a (*consequence, has no prominent nodes on the ribs of the left valve. Both the typical P. watUi and its variety moran are allied to P, but are much taller and have relatively much shorter ears and narrower ribs. The degree of convexity is approximately the same in P, hamlhi! and P. tratU't var. mnrani,

P. irattati var. moran is known so far only from beds exposed on Mr. T. H. Moran-s place, Priest Valley, Monterey County, whei*e it is associated with Area (cf.) trllineata Conrad, Ostrea hirldii Carpenter, EehhnirachnhiH (c/.) rxcentrleuA Elschscholtz, and Scutelln fahhanWt Merriam This fauna probably indicates a lower Pliocene horizon.

The type is an almost perfect left valve (IJ. S. N. M. No. 164929) and, together with the other figured specimens, comes from Mr. Moran's place in Priest Valley, Monterey County.

Kangr.

Pliocene (lower). T. H. Moran's place, SW. sec. U, T. 20 S.. R. 12 E., Moimt Diablo meridian. Priest Valley, Monterey County (Hamlin and Arnold).

PeCTEX (LVROPKCTEX) ASllI.EYI n. sp.

PI. XLVII, figH. 1 and PI. XLVIIl, fir. 1 18a5. Ffcteu ejttrellamis Aphley (not of Conrad, 1857), Proc. Cal. Aca*l. Si-i., ser. 2, vol. 5, 1895, p. 338.

Decrtptton, — Adult shell iiveraginjr a}>out 150 millimeters in altitude, longer than high, subequivalve, convex, inequilateml, the posterior portion of the disk obliquely produced; sides concave above. Right valve with 18 or 1*J either squarish, flat-topped (convex-topped near umbo) ribs which are more or less prominently sculptured by numerous thread-like, somewhat imbricated, radial ridges; interspaces narrower than ribs, channeled and ornamented by an intercalary riblet and, in the later stages of growth, })y several imbricated nidial lines; hinge line about one-half length of disk; anterior ear somewhat produced, prominently notched and sculptund by numerous imbricating incremental lines and several more or less prominent unequal radials; posterior ear slightly shorter than anterior, and similarly sculptured except with more, but less conspicuous, radials. Left valve slightly more convex than right and similar to it except that the ribs are slightly narrower and more convex, and the interspaces are correspondingly wider and generally have the bottom entirely sculptured with subequal radial lines, with the prominent intercalary lacking; ears suiequal, rectangularly truncated and sculptured in a similar manner to the ear of the right valve.

D'niunttipnH, — Alt. 152 mm.; long. 175 mm.; hinge line S5 mm.; diameter 65 mm.; apical angle 110\

This magnificent species is chamcterized and is distinguishable from allied forms by its great relative length and numerous ribs a nearly

Pliocene Peotens. 123

allied fonii, having only 16 or 17). P. anhhyi is distinguirthible from P, cerrowith which it is generally associated, by the smaller number of ribs and the longitudinal sculpture of the same.

In the Third street tunnel, Los Angeles, P, axhleyi is associated with the following fauna: Pectin opinitia P, JftfUiuritus P. fy'droamui P, Glyphis Nansa n. sp. ?. sp. indet.. Area mMlticosUita Lima hamlin! Bucchium sp. indet., NeterHa rednzinna Astarte sp., Iiene oregojiejuii OHtrea veatchll Pleurotoma sp. indet., carditoid, coral, bird bone, crab's claw. This association of species indicates a horizon of the lower Pliocene.

A fragment of a large specimen of P, ashhyi was found hx Doctors Dall and Stearns in the low hills across the mesa three-fourths of a mile northeast of Pacific Beach, near San Diego.

P. Wihlyl is also found in the Pliocene at Island and San Fernando. The type is from Cerros Island, and is now in the collection of the University of California. Named in honor of Dr. (J. II. Ashley, of the United States Geological Survey, whose pioneer work in the Sanbi Cruz Mountains added greatly to the knowledge of the West C/oast Tertiary.

Pliocene. Cerros Island, otf Lower California (Univ. of Cal.): Temescal Canyon, Santa Monica Mountains, Los Angeles County (Rivers): Third street tunnel, Los Angeles (Hamlin); near Pacific Beach, San Diego (Dall, Stearns); San Fernando, Los Angehvs County (Ashley); Cosmalia, Santa Barbara County (F. M. Anderson): Olinda, Puento Hills, Omnge County (Eldridge).

PkC'TEN (Pl.AdKKrrENIUM) CERROSENSIS (labb.

PI. XLIV, Hjr. 5; PI. XLIX, fiKs. 1, la, ami \h.

1869. Pevtt'u ctrroHeiiifix (iabb, Pal. Cal., vol. 2, 1H()0, p. ;?2, pi. 9, firn. 5.'), 5oa.

1898. Ptrten crrmscHsis (iabh, Dall, Trans. Wagner Free Inst. Sci., vol. 8, pt. 4, 1H98, p. 705.

1898. IWteu ( PliKjloctenium) mhvrntrusus Dall, Wajrner Free Innt. Sci., vol. W, pt. 4, 1898, j>. 707

1903. IWft'n {Phif/loi'tt'iiium) .snJnejUrirosns Dall, ArnoM, Mem. Cal. Acad. Sci., vul. .'i, 190;i, j). 114.

1904. JWteti HiihreutrU'oxua Dall, Rivers, Hall. So. Calif. Acad. Sci., vol. 8, no. 5. p. (>9. 1904. 'H' rmtrirttsits Sowerby, Rivers. oy>. c//., p. H9.

//'pt/o/f. Adult shell averainof ai)<>ut loo millimeters in altitude, somewhat longer than hioh, sulHMjui valve, biconvex, ineijuilateral, ))einof somewhat obliquely produced posteriorly; margins more or less sharply serrate; sides nearly straight and sloping at a rather angle. Right valve slightly less conve.x than left, with 21 to 28 prominent rounded, sm()<)th-t(>])ped which in the adult broaden and become ornament'd with looped incremental lines near the periphery of the disk; interspaces narrower than the ribs, with sloping sides and flat, narrow bottoms, which are ornamented by a dense fringe of tine, sharp concentric lamelhe; hinge line a little more than one-half as long as disk; anterior ear slightly longer than postcM-ior, and ornamented by ridges and numerous inibricating concentric lines; byssal notch of medium size; posterior ear nearly

124 TEKTIARY AND QUATERNARY PECfENS OF CALIFORNIA.

rectangularly truncated, and ornamented by more or less prominent radiating ridjifes and numerous tine incremental lines. Ift valve similar to the right, except that the ribs are slitrhtly narrower and the interspaces wider; anterior ear showing a shallow concave margin near disk, otherwise ears similar to those of th( right valve. Hinge similar to that of P. rtrculariH vr. lequlsiilvufus,

-Alt. lOo mm.; long. 112 mm.; hinge line nun.: diameter 8.5 mm.

This species is close to var. but may be distinguished from that species by its larger size when adult, less ventricose valves, more and rounder ribs, and shorter hinge line. The San Fernando forms have slightly ribs and, so far as known, do not reach the enormous size (the type being over 200 millimeters in altitude) attained the specimens from the locality: otherwise they are identical. One Ventura County specimen has an altitude of over 100 millimeters.

A variety of this species (No. 14044 C. S. M. B.) from Brown's Canyon, near Santa Monica, Ios Angeles County, has a somewhat wider umbonal angle (105 ) and a slightly obliquely truncated posterior ear on the right valve: otherwise the specimen is typical.

is contined to the Pliocene, but no doubt iiinges through nearly the whole of this The forms in the San Fernando beds show a closer aflinit}- to var. itf/in'ff/affus. of which they may be the precursors.

Pliocene. Station 3, 1 mile north of Canuilos, Ventura County (Watts); San Fernando tunnel, Los Angeles County (Ashley, Watts, Arnold); Temescal Canyon, Santa Monica Mountains, Angeles County (Rivers); Browns Canyon, Santa Monica, Los Angehs County (Watts); Pacific at Twenty -second and H stnets, San Diego, and Cholas Valley, San Diego County (Stearns); Pacitic Beach (Hemphill. Arnold): (Jerros Island, off Lower California (Veatch and othei-s): Turtle Bay, Lower California (Hemphill).

Pecten (Pi.a(;i()Ctenium) n. sp. PI. XLIX, iijfs. 2, 3, and 4.

— Shell averaging about 30 millimeters in altitude, slightly longer than high, both valves moderately convex, disks slightly obliquely produced posteriorly, moderately thick; disk generally characterized by several more or less prominent concentric zones of interrupted growth, whiidi show as color bands even on the fossil shells; sides nearly straight; margins serrate. Right valve with 18 to 20 flat-topped, squarish ribs, which tend to flatten out and become more convex topped in the later stages of growth; narrower than the ribs, and crossed on the bottom by numerous, fine, sharp, incremental lirula?, which become obsolete on th(. ribs excepting in the later stages of growth; hinge line somewhat more than one-half length of disk; anterior ear slightly produced and ornamented by 4 or 5 prominent radials and numerous incremental lines; byssal notch deep and sharply defined; posterior ear slightly obliquely trun-

Pliocene Pectens. 125

cated, and sculptured obsolete radials and rine incremental Left valve sinular to right, that the are narrower and the intirspaces correspondingly

\M) nun.: lon-. 81 nun.: hine line 17 nun.: diameter 1: mm.: umbonal ancjle 1*5-.

This species is characterized by the number of its ribs and the concentric imbricating bands of interrupted growth. It is distinguishable from ('t-n'oHcthsfs by its fewer ribs, less promimnt liruhv on the sides of the ribs, and its promincMit concentric bands of interrupted growth; distinguishable from rtrcuhtrls and varieties by its less ventricosity, fewer ribs, and its characteristic concentric sculpture. Specimens of this specie> were noticed in a box in the National Muscnmi with suhrmfrimsHs <:r/7VAV/ //.v/.v| from Pacitic Heach, San Diego.

roach-ri is so far known only froni the PlioccMic of Pacitic Beach, near San Diego. Tv]>e and cotype now in tlu collection of Delos Arnold. Named in honor of the late Dr. A, G. Coopei*. one of the pioneer ])aleont()logists of the Pacific ('oast.

Pliocem*. Pacitic Hcach, San Diego (Hemphill, Arnold).

Pkcten ciKcirLAias Sowerby. PI. XLII, lirs. :;, 4, PI. XIJV, lis. v/, tJA, ami 7.

ls:5. Perttn tum'uhiH Sowcrhy, l*roc. Sim-. I.oikL, 18.Sr>, p. KUJ; not I', din tunwhis Turton, 1S22,

imr Z<'iU*ii, IS8(). ls;>. JWtfut cirmlaris iivivrliv, Zool. Sue, lS.'ir>, j, 1843. Pectrn rcntriruaus Sowi'rby, Thi's. Coin'h., vol. 1. pt. 1, Pt-, p. ol, p], pj, Jirs. is, and 2(>;

-f- J. ttouiiinx Sowerby, iSSo. 1843. I'tctmcirndnria Sowcrhy, Tho?'. Coiu-h., I, pt. 1, Pocton, p. M, N). IS, 12. Ii<:. 28. 18o2. I*(rteii rr///r/Vv>.v//x Soworhy, Reovi*, (ouch. Icon., vol. 8, IVcten, sp. .31, 1852, pi. 7, iis.

31 a and h. 1853. iWtni rirrii/aris Kcevc, Conch. Icon., vol. s, June, 1853, IVctcn, sp. 137, ]>I. 31, fig. i;)7. 18<>9. rentrirnxnn Sowerby, ( Jabb, Pal. Cal., vol. 2, p. 104 ( - /'. \ar. in

juirt). 1888. IWtin />////vV-o.s//.s Sowerby, Kiister and Kobclt, ('<nch.-Cab., vol. 17. pt. 2, sp. p. inO, tat. 2s,

tigs. 1-3. 1888. IWtt'n /)i'ntiper(('it) rirrnlni'iH Sowerby, Kiister and Kobclt, Conch. -( ab., vol. 17, pt. 2, sp. 151,

p. 188, taf. 51, tigs. 5-8. 18S8. iWtti, /r////vVo.s//.v Sowerby, CooiK-r, Seventh Aim. Kept. ( al. St. Min., l8SS, p. 258. 1S98. I*ertrn I'hn/litHcniuin) rmfi'lmsiis Sowerby, I >all, Trans. Wagner Frci* Inst. Sci., vol. .3, pt. 4,

1898, p. 710. [- Inrn Orb., 1847; ? innuntla Val., Voy. Venus, 1835. pi. n>. ti;r. ;5 [fi'le

Dall, 1808.)] 1808. Pertt'n iPtrfrn) ronipnrtu.< Dall. Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 108, p. 707, pi. 34,

tig. 5 ( right valve ot a young specinuMi). 1003. Perttn I'htffiortriiiiuii ) rt'ntrirnsii.s Sowerby, Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, j). 114,

11, figs. 3, 3a, and Cvi I*, var. .f7//.</'/(Vf///.s- 18(>3, in part). liH.)4. IWtcn Sowerby. Keep, Wi*st Am. Shells, pp. 41-42.

-Shell averaging about 4r millimeters in altitude, about as long as high, subequivalve, very convex, ine(|bilateral. the posterior portion of the disk

12r> TKRTIARY AND QrATKRNARY PECTEN8 OF CALIFORNIA.

hviug somewhat ohliqiioly produced; iimrginH sharply serrate: sides quite concave Right valve with ID to 21 squarish, close-set, smooth ribs, which, in the adult, flatten out and have sloping sides near the periphery of the disk; interspaces Viry narrow and channeled: whole surface of disk sculptured by obsolete, wavy lines of growth: hinge line two-thirds length of disk: ears equal in length, separated from disk by a prominent groove posteriorly and small ridge anteriorly; anterior ear with 4 rather faint radials, and numerous tine, imbricating incremental lines; byssal notch deep, itii! upper side !)eing parallel with the hinge line; ear with delicately curved extremity, and ornamented by tine incremental lines, and also on the lower half by faint radials. Left valve darker colored than right, and with the ribs narrower, flat-toppexl, and having sloping sides; interspaces wider, and <-oven lKth on the bottom and sides by tine, sharp, concentric lamellae; eafF a- iu the right valve, except that the anterior one is not so conspicuously riot/b<-d. Hinge strong, the pair of cardinal ci'ura in the right valve exceedluly w<'JI di-veloped. Color patterns from light to dark brownish red.

/A/////'/<'//. — Alt. 44 mm.: long. 47 mm.; hinge line 32 mm.: diameter 33 mm.

'Jbii- typical form is chanicterized by its great and regular convexity, broad /r/i-. iifid Mrong hinge. Type from (iulf of California.

J'urid living from the (rulf of California southward to Panama; in the Pleis- '/*4-fji farthT north. Krroneoush' reported from the Philippines by Sowerby.

,'y my. Oulf of (,-alifornia to Panama (Sowerby, Carpenter, Button): St. Klena,

;'.i-iHU/;*rni'. San Pro: San Diego: Iwer California (Hemphill, Steams, Orcutt); \iriiLui'u: San IVdro; San Diego (Arnold): Ventum (-ounty-

i 0. (.'hulas Valley, neir San Diego (Stearns).

PvjrrKS (PuorKAMUsiini) rivers n. sp.

PI. XLIV, fiKH. 8 and I).

/////V//*. Shell averaging alwut 14 millimeters in altitude, about as long

,.. ijii . <;irruUir in outline, equilateral, compressed, white, translucent: margins

. i,</-;ij Kiglil vaJv<' much surface smooth except for numerous

tiui . K/nUti. imlricating lamellas hinge line one-half length of disk: ears

',..<it,i!\\\ from disk by impressed line, subequal in length: the anterior

.. .*;ii4 111 lioiit with 12 subeijual prominent radials and numerous

tti'iilar. iin;ri*aiinj. incremental lamelhe: the wsterior slightly obliquely

.t.iuMi': .-xiilj/turi'd >-iniilarly to the anterior, except that the radials are

. iH,r.itU'.\A-: nofrli of nuulium prominence. Interior of disk smooth

. I'l .11 aluiuMt vl J.v is reached, when about to 22 small, rounded,

..' rill, \i[>[/*vi Hft'l #'>#;ntiriue to the ixM-iphery. Left valve somewhat more

... I.- liiaii Ml* nyUl, and ornamented externally by numerous unequal,

,, v;ii.j,ii*i.* xuihti*HUi rilM, the alternate ones being intercalated between

r:,jiii iit// I ou.- yyb/;le siirfai'c sculptured )>y tine imbricating lamellae;

Pleistocene Pecten8. 127

anterior ear similar to that of the right valve, except that it is more strongly radially ribbed and is less sinuated; posterior ear similar to that of right valve, except that it is more strongly ri})})ed. Interior of left valve similar to that of the right, and having the radial ribs developed only after attaining an altitude of about 15 millimeters.

Dhnenskms. — Alt. IT mm.; long. 18 mm.; hinge line 9 mm.; diameter 3.5 mm.

This species is very close' allied to P, <flask('N.s!i<. of which it is undoubtedly the precursor. It differs from th(* latter in having the external ribs on the left valve more prominently imbricated above, and in having the internal ribs of both valves appearing only after an altitude of about 15 millimeters has been attained.

The relations (existing })etween P. vlre'rH! and are a good illustration of Hyatt's law of acceleration of development.'' In the former, the Pliocene precursor of the latter, the internal riblets are developed only in the adults or after an altitude* of aljout 15 millimeters is reached. In alaska7i8iH the living species, this characteristic has ))een pushed backward in the process of development to or nearly to the embryonic stiige, continuing, however, in the later stages of growth, and appearing as a well-developed internal riblet fi:om near the umbo to the periphery.

P. rivers is known at present from only two localities, the Pliocene of Santa Monica Canyon and the Pleistocene (lower San Pedro formation) of Deadman Island, near San Pedro. The species is named in honor of Dr. J. J. Rivers, of Oceanpark, whose work in the fossiliferous deposit.s of Santa Monica and vicinity has thrown much light on the distribution of the later Tertiary and Pleistocene formations.

The type, which is now" in the collection of Delos Arnold, is from the Pliocene of Santa Monica Canyon, Los Angeles County, and was collected by Doctor liivers.

Pleistocene (lower San Pedro formation), Deadman Island, near San Pedro (Arnold). Pliocene. Santa Monica Canyon, Los Angeles County (Kivers).

PLfJlsTociJXE ri:( TEXS.

[Tlidso known first to appear in Pleistocene formations.]

PeCTEN (PecTEN) DIEIJENSIS Dall.

1*1. LI, ligs. 1, 1</, lUid \h.

1844. Ih'rtmi floridns Hinds, YamA. Voy. Siilpli., 1S44, p. ])1. 17, tijr. not Ostun Pfcfen) thrida

(niieliii, (jhle nail). 1852. Perten fhiridii.'i Hinds, Hi'ev% Conch. Icon., vol. 8, lSo2, 8, ti. and wp. 'M. 1888. ( floridns Hinds, Kiister and Kohrlt, C'.-ral)., vol. 17, pt. 2, iind

Poctcn, sp. 17.'J, taf. o7, 2.

'All iiioditieutions variations in projrresiive series tend to appear first in the adolescent or adult stages of irrowth, ana intn to Im; inlieriled at earlier and earlier stages, acconling to the laws of \intil they either become embryonic or are out of the oritranization replaced in the development by characters of later origin".— A. Hyatt, in "Gene-is of the Arietidoe." prefa('e. p. ix.

128 Tertiary And Quaternary Pkctens Ok California.

1888. Jnmra florida Hiiultf, Cooper, Seventh Ann. Kept. Cal. St. Min., 1SS8, p. 244 ( /'. hwphifH ami

P. stcanixii in part). 1898. IWtfn (Perten) (liefjnmH Dall, Trann. Wagner Free Innt. Sci., vol. ,S, 4, 1898, i>. 710. 190.S. Pecten iVu'geimH Dall, Arnold, Mem. Cal. Sci, vol. p. 106, pi. 12, fijr. 5. 1904. Peiit'n dieynnnim Dall, Keep, Went. Am. shells, p. .'{9.

Di'Acrljftlnn, — Shell averaging about ()0 in altitude, longer than high, inecjuivalve, plano-convex, or nearly so, etiuilateral and with smooth margins: base evenly rounded; sides slightly concave above. Right valve somewhat convex (more pronounced near the um])o), and ornamented by about 22 or 23 prominent T-railshaped ribs, flattened, and generally longitudinally ridged or sulcated on top, which overhang deep, narrow, flat-bottomed interspaces; whole surface sculptured by luimerous tine, sharp, incremental lines; hinge line slightly less than one-half length of disk; ears equal, slightly convex, rectangularly truncated, sculptured by tine, sharp, incremental lines; anterior- ear with small byssal notch. Left valve flat or nearly so, generally concave near apex, ornamented by 21 or 22 prominent, narrow, convex-topped ribs, which are sejmrated by concave- bottomed intei'spaces about equal in width to the ribs; whole surface promintMitly sculptured by regular, tine, sharp, concentric, niised lines; ears concave, convexly truncated, and ornamented by the same concentric sculpture as the disk. Color, red and reddish brown, th( left valve always being nuich darker than the right.

Z>////<"//.v/w/x. — Alt. 58 mm.: long. nun.: hinge line 2t mm.: diameter 13 mm.: umbonal angle (left valve)

This species is distinguishable from its nearest relative, and proliable precursor, stfftrnsif, the smaller number and greater height of ib* (/f'tf/rnxifi) ribs, and relatively somewhat longer hinge line. The ribs of (llt'(jniif!f< have sometimes jis many as three longitudinal sulci. Mrs. Oldroyd has two specimens taken from fishermen's nets at San Pedro, which measure ovtr 150 millimeters inches) in length, and are exceptionally high colored for this species.

Living. Monterey (Hutton; Mrs. Lambert and others): San Pedro (Oldroyd; Raymond); Catalina Island, 10 fathoms (Arnold); San Diego (liaymond). (In all cases dredged.)

Pleistocene. San Diego (Hemphill).

Pp:tTKN (NoDiPKCTKN) Sowerby. PI. LIl, tij?. 1; PI. , fips. 1 and ir/.

18ii5. Pf'cten Proc. Zool. Soc, 18:i5, p. 109

1842. Pevten anhnodostts iowQrhyy Thes. Conch., vol. 1, pt. 1, 1842, p. 112, lo, fijr. 97.

1852. Ptdeii mhnodnsiix Sowerby, Reeve, Conch. Icon., vol. 8, Monop. (Jeniis Petten, Nov., 1852, pi. 4,

fip. and p. 20. 1867. Perteu interinedi un Ckinmdy Am. Jour. C'onch., vol. ',i, 1867, p. 7 {tide Dall, 1898). 1888. Pedeti sidmodoms Sowerby, Kiirter and Kobelt, Conch. -Cab., vol. 17, pt. 2. Spondyhis und Peeten,

no. 71, p. 112, taf. 82, iig. 3.

1897. Lip'opfctcn nnhu<)doftm< Verrill, Tranw. Conn. Acad. Sci., 10, p. 64.

1898. Peeten {Xodipecten) xidwodosux 8owerby, Dall, Trans. Wagner Free lnt. .Sci., vol. 8, pt. 4, 1898,

p. 710.

Pleistocene Pecten8. 129

Description, — Shell avemging about 110 millimeters in altitude, slightly broader than high, subequivalve, subequilateral, of medium thicknes.s, somewhat ventricose, and with margins finely serrate; base regularly rounded; sides sloping and nearly straight. Right valve slightly less ventricose than left, with about 9 or 10 broad, flat, subequal ribs; interspaces subequal, with slightly rounded bottoms; whole surface sculptured by numerous (averaging about 7 on each large rib) radiating riblets, whose surfaces and interspaces are crossed by numerous fine, wavy lirula of growth; several faint undulations are also generally noticeable on the disk; hinge line slightly longer than one-half length of disk; anterior car about one and three-eighths times the length of the posterior, arcuate in front, and ornamented by seveml prominent radiating riblets and tine, sharp, incremental lines; byssal notch not very prominent; posterior ear rectangularly truncated and sculptured similarly to anterior. Left valve resembling the right except that it is slightly more ventricose and the ribs are ornamented by more or less elevated, hollow nodes, those on the alternating ribs being the more prominent.

Diiiumslmis, — Alt. 112 mm.; long. 120 mm.; hinge line 66 mm.; diameter 45 mm.

Doctor Dall is of the opinion that there is little reason for separating this form from the vodosuj of the Antilles, although he says the latter is generally thinner, and has the nodosity more pronounced.

A fragment of a left valve of a variet\' of P. sulnodos-m from the upper San Pedro formation (Pleistocene) of Deadman Island, San Pedro, has 17 ribs whose sides are concavely excavated, thus giving them a somewhat T-shaped cross section. The middle rib and the fourth rib on each side of it are very prominent, while the other ribs are much smaller. Sculpture as in typical P. 8idmodosuj<,

The specimen figured is a living shell from the western coast of Mexico, and is now in the collection of the department of geology, Leland Stanford Junior University.

Living. Coast of Lower California to Kcuador and the tropical shores of South

America (Carpenter). Pleistocene. San Pedro (A. A. Wright: Arnold); Cerros Island and other points on

the coast of Lower California (Dall). Pliocene. Temescal Canyon, Santa Monica Mountains, Los Angeles County (Rivers).

Pecten (Chlamys) i.ATiAURiTi's Coumd var. oerkitensis n. var.

PI. XLVI, fis. Band 7.

1908. I*erteu {('hlfnnifs) latidnrifiis Conrad vAr. Arnold, Mem. Cal. Acad.Sci., vol. 3, pt. 2, 1908, p. 112, pi. 12, fig. S; not JWten fragilis Jeffreys, Ann. and Maj. Nat. Hint., 4th eer., vol. 18, 187(), p. 424.

//'pf/'on. — Shell of same general type as I/itiaurittfM. More compressed and much thinner: ribs seven to nine, very low and rounded, with shallow, rounded interspaces; surface smooth, the concentric sculpture being nearly obsolete; hinge long; ears rather sharply pointed. 17260— No. 47—06 9

130 Tertiary And Quaternary Pectens Of California.

Dtmetmons, — Alt. 26 mm.; lon. 26 mm.; hinc line 25 mm.; diameter 7.8 mm.

This variety' is distinguisliable from DalPs vnvietyftccico/tf, which it resembles, by Iiaving a longer hinge line and generally more pointed ears.

Found associated with the typical species in the Pleistocene (upper San Pedro fonuation) at San Pedro and San Diego.

Pleistocene. San Pedro; San Diego (Arnold).

Pectex (Chlamys) latiauritus Conrad var. delosi n. var. PI. XLVI, ligs. 9, 10, and lOa.

D''ript'um. — Shell averaging about 12 millimeters in altitude, slightly longer than 'high* both valves onlv slightly convex, inequilateral, the disk being decidedly oblique to the hinge line and somewhat produced posteriorly; sides nearly straight; margins rough. Right valve with about 16 prominent smoothtopped ribs; interspaces wider than the ribs, flat-bottomed and ornamented on the bottom and sides by numerous prominent, regular, equidistant, imbricating, incremental lamella*; hinge line as long as, or slightly longer than, the disk; ears equal in l(; anterior ear long and narrow, separated from the disk by a deep, sharply defined, byssal notch and sculptured by tive or six prominent radiaLs and numerous, regular, imbricating, incremental lamella'. Left valve similar to right except that the ribs are slightly narrower and the incremental lamellae extend over the tops of the ri})s in some specimens; ears acutely pointed and sculptured numerous regular, sharp lamelUe; anterior somewhat shorter than the posterior and with four major and as many intercalary radials; posterior with four or five radials.

— Alt. 12 mm.; long. 12.5 mm,; hinge line 13.5 mm.; diameter 8.5 mm. ; umbonal angle W.

This beautiful little Peeten,, one of the smallest found in our fauna, is characterized by its extremel}' long hinge line and prominently lamellated surface. It is distinguishable from the typical and varieties, with which it is allied, by its longer hinge line and prominently lamellated interspaces.

The living s])ecimens have the ribs more prominently lamellated above than the fossil forms. var. diUhsi appears to occupy somewhat deeper (and consequently water than the typical form. The of Infiatirlfm found in the Santa Barbam aiul Monterey regions appear to lean strongly toward this variety.

deloHi has been found fossil so far only in the lower San Pedro formation (Pleistocene) at Island, near San Pedro. Types now in the collection of Delos Arnold, the writers father, after whom the species is named. Living specimens dredged in 15 fathoms at Catalina Island.

Living. Santa Catalina Island, Los Angeles County, in 15 fathoms (Arnold); Santa

Barbara (Dall); Monterey (Button). Pleistocene (lower San Pedro formation). Deadman Island, San Pedro (Arnold).

o

Pleistocene Pectens. 131

Pecten (Chlamys) LATiAUiiiTUS Coiirad var. fucicolus Dall. PI. XLVI, ligs. 8 and H//. 1898. Pecien latiaurilm vat. juciroluj* Dall, Trans. Wagner Free Inst. Sci., vol. o, pt. 4, 1898, p 710.

Th'Hcrtptlim, — Shell of same goneral type as P, latlaiintiis. Moderately compressed, smooth, concentric sculpture obsolete; ribs low, rounded, wide, entire; hinge line shorter than in the type, and without any sinus between the posterior ear and the disk.

DimeimumH, — Alt. 80 mm.; long. 31 mm.

*This form lives attached by the byssus to the giant kelp of the Californiau coast, and the absence of shock, due to the floating situs, is probably correlated with the obsoles(;ence of the ribs and the posterior sinus. Intergradations with the type are not at all rare.'' (Dall, 1898.)

Kancje.

Living. Santa Barbara, south to Cape St. Lucas (Dall). Pleistocene. San Pedro; San Diego (Dall; Arnold).

Pecten (Chlamys) latiaukitus Conrad var. monotimekis Conrad.

Pi. XLVI, figs. 4, 5, andoa.

1837. Pfen Conrad, Jour. Acad. Nat. Sci. Phila., vol. 7, 18.37, p. 233, pi. 18, fig. 10.

1863. Pectetx QoiMTiX Brit. Assn. Kept., 18()3, p. (U5.

1888. Pecieii moiwtimerh Conrad, Kiister and KoMt, Conch. -Cab., vol. 17, pt. 2, Spondylus und Pecten,

No. 257, p. 276, taf. 72, figs. 7 and 8.

1888. Pecten latiaurUus Connid, Cooper, Seventh Ann. Kept. Cal. iSt. Min., 1888, p. 2o7 (in jart).

1892. Pertei} monotimeris Conrad, Keep, West Coast Shells, 1892, p. 167, fig. 140.

1897. Pecten {Leptopeden) monot Imeria Conrid, Verrill, Trans. Conn. Acad. Sci., vol. 10, i. 69.

1898. PeHrn hitianritux var. mouothnerin Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898,

p. 709.

1903. Pecten {('hlami/a) latinurituft Con, var. monotimerh Conrad, Arnold, Mem. Cal. Acad. Sci., vol. 3,

pt. 2, 1903, p. 112, pi. 12, figs. 4 and

1904. Pecten var. inonotinieris Conrad, Keep, West Am. Shells, p. 40, fig. 20.

yA'.sf — Shell of the general type of lat!(nirltHi< hut more oblique, inflates!, and markedly shorten', with smaller ears; ribs generally prominent and squarish, and interspaces deeply channeled; incremental sometimes very pronounced.

— Alt. JUnnn.; long. Umm.; hinge line IT) mm.; diameter iMnm.

This variety is characterized hy its ventricosity, well-delined rihs. and relatively short disk and hinge line. var. immofintcrf'fi is very common at Los Cerritos Hill, near San Pedro. ))ut is much rarer in the other Pleistoc(*ne localities than the typical /'.

Found in the fossil stat( in tlu* upper San Pedro formation (Phnstocene); also occurs recent.

Kancje.

Living. Fort Point, San Francisco (Button); Santa to San Diego (Dall). Pleistocene. Santa Barbara; San Pedro (Dall); San Pedro; San Diego; Ventura (Arnold); Newport, Orange County (No. 11895, C. S. M. B.) (Watts).

132 Tertiary And Quaternary Pecten8 Of California.

Pecten (Plagioctenium) CIRCULARI8 Sowerby var. jcquisulcatus C/arponter.

PI. L, figs. 1, 1, and Ih; alwo text fig. 1, p. 45; fig. 2, p. 46.

1863. Perten [rentricoims var.?] ivquisvlcatus Carpenter, Brit. AsHn. Kept., 1863, p. 646.

1865. Pfcteu (?var. ) irquimlccUvs Ann. and Mag. Nat. Hint., 3d wr., vol. 15, 1865, p. 179.

1869. Pectni rentricomH Gabb, Pal. Cal., vol. 2, 1869, p. 104.

1888. Pectm nquvndcaUis Carpenter, Kuster and Kolielt, Conch.-Cab., vol. 17, pt. 2, Spondylus iind

IVcten, no. 249, p. 269, taf. 71, figs. 1 and 2. 1888. Pecten ventricoms Cooper, Seventh Ann. Rept. Cal. 8t. Min., 1888, p. 258 (Quaternary reitjrd

only). 1892. Pecteii Carpenter, Keep, West Coast Shells, 1892, p. 1()6, fig. 139. 1898. Pecten xquwulcatiu Williamson, Proc. U. S. Nat. Mus., vol. 15, for 1892, p. 193. 1898. Pedeti {rentricosnm var.?) nquimlcatus Carpenter, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt.

4, 1898, p. 711. 1898. Pf'den ( Platjioctenium) rentricoHut* Dall, Trann. Wagner Frec Inst. Sti., vol. 3, pt. 4, 1898, p. 710

(in part).

1902. Pecten nquisiilcattt Williamson, Bull. So. Cal. Arad. Sci., vol. 1, No. 5, May, 1902,

pp. 51-64, pis. 4-6. 190Ii. PecU'u (PlagiocUmium) reiitricomi* Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 114, pi. 11, tigs. 3, 3ti.

1903. Peden {PUiglocteniuin) netmnni AmoM, Mem. C-al. Sci., vol. 3, 1903, p. 113, pi. 11, figs. 1

and la (a young shell) .

1904. Pecten icquutulcatus Carpenter, Keep, West Am. Shells, p. 39, fig. 18.

Description. — Adult shell averaging about 75 millimeters in altitude, much longer than high, the anterior portion of the disk being obliquely produced; side somewhat concave above; shell rather thin: margins serrate. Right valve with 20 to 22 inodeniteh prominent, flat-topped ribs separated by much narrower, flatbottomed interspaces; lateral areas about as wide as two normal ribs; whole surface of disk sculptured by line, ship, looped, incremental lines; hinge line about fiveeighths length of disk; ears equal in length; anterior ear sculptured with fine concentric lines and 7 or 8 more or less prominent dials; byssal notch deep and sharply defined; posterior ear rectangularly truncated, and sculptured by concentric lines and obsolete radials. Left valve with narrower ribs, which have more sloping sides, and more prominent lamella' of growth in the interspac*es; interspaces correspondingly broader; ears similar to those of right valve, except that the posterior is not sharply not<*hed. </olor, white to light reddish yellow blotched with shades of reddish brown, the left valve being always perceptibly darker colored than the right.

Dhnenmrnii. — Alt. 72 mm.; long. 88 mm.; hinge line 51 mm.; diameter 36 mm.; umbonal angle 100.

This variety is more or less variable in regard to its convexity, obliquity, relative width and height of ribs, and colomtion. In the young specimens the right valve is more convex than the left; the ribs are relatively much squarer and more prominent, the intersjiaces correspondingly narrower and deeper, the hinge line comparatively longer, and the angle appears to !>e less, than in the adults. The tendency of the ribs to flattcMi out and the contentric sculpture to become more irregular and rough as the shell grows older is evident to a gi-eater or less degree in nearly all of the specimens examined.

Pleistocene Pectens. 133

The shells, as a rule, are more convex (the right valve noticeably more so than the left), somewhat less oblique, and the ribs are slightly broader and more compact, than the living specimens. The young of P, var. quisulcafm have the chamcteristics of the Pleistocene form and are scarcth' distinguishable from the young of P, cevroftfifiH,

P. var. peqnimclcaUti varies from the typical P, rJrcuhirls of the (iulf of California and west Mexican coast fauna by its larger size when adult, flatter and thinner disk, narrower ribs, and more subdued coloration. These two forms seem to have separated during the Pleistocene, the living shells not appearing to give a satisfactory connection, while a large series of Pleistocene specimens shows an obvious gradation. Doctor Dall p. 6JU), in speaking of the influence of environment upon the Pectens, thus mentions the relation P, and var. xquianlvafm: ''As in mammals and birds, the same species in the northern part of its [Pecten] range is larger than in the south, unless it is a distinctively tropical species. But in color the rule is reversed, the southern specimens being lighter and more brightly tinted than the northern ones in the same species. The specimens which live in deep water and swim actively are usually thinner shelled and smoother, while those which inhabit the lagoons are heavier, have more conspicuous concentric, sculpture and more solid shells. These differences are very marked in our common east coast P, !r radians of which P, dislorafm Say is the southern lagoon form; and parallel differences appear in the similarly related P, rircularii<\ and its variety fefjniHufcaftt on the Pacific coast

P. var. ii'quUuhuttm ranges from the Pleistocene to the Recent fauna.

Rancik.

Living. Santa Barbara to Pacific side of Lower California.

Pleistocene. San Pedro; San Diego; California (Hemphill, Stearns, Orcutt);. Ventura; San Pedro; San Diego (Arnold); Springville, Ventura County (lowers).

I:cTKN (Propeamusium) alaskensis Dall. PI. LIII, tigH. 2, 2(/, and X

1872. Pecien ( Pseiidamusium/) Dall, Am. Jour. Conoh., vol. 7, 1872, 155, pi. 16, fig. 4.

1886. Pertm Propeamumnm) nlakemiit Dall, Hull. Mu8. Coinp. Zool., vol. 12, no. 6, 1886, p. 215, pi.

5, figs. 7, 7n.

1887. Not Pi'den WhiU*aves, Trann. Roy. 8oc. Canada, vol.4, sec. 4, 1887, p. 119 (=P.

ranamreriiiHiii Whiteavos, 1893).

1888. Pectrn alaahnsiii Dall, Kiisterand Conch.-Cah., vol. 17, ])t. 2, Spondylus und IVcten,

s]). 220, p. 245, taf. 64, figs. 7, 8.

1889. Perhn {Propeamnninm) ohiskensis Dall, lUiU. V. S. Xat. Mus., No. 37 1889, pi. 5, ligs. 7, 7a. 1893. Pecten Ahinkrnsis Dull, Nt'wconilH', Kt*pt. on Mar. Sli. Brit. Columbia, Hull. Nat. Hist. Soc.

Brit. Columbia, 1893, art. 5, p. 53. 1895. Pecten {J'seudanuulnm) Afa.kennii Taylor, Trans. Roy. Soo. Canada, 2d sor., vol! 1, 1895, 801'. 4, [). 27.

1897. AniuHinm A/mkcnsiA Dall, Verrill, Trans, ()nn. Acad. Sci., vol. 10, p. 65.

1898. Pecten Prnpaunns'nun) d/ashnslM Dall. Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 711.

The original description is as follows:

Deacptption, — Shell nearly equilateral, inequivalve, flesh color, with a blush of salmon color on the umbo of the supcMMor valve. Internally white, the salmon color

134 Tertiary And Quaternary Pectens Of California.

showing through the valve. Shell sul3or])icular, barring the auricles, which are wide and prominent. Lower [or right] valve flattened, 0.1 inch (2.5 millimeters) smaller than the upper one; sculpture of fine, close, equal, concentric ridges, sharply defined and separated by narrow non-cnaliculated grooves. Valves covered with a fine velvety epidermis, ashy and very finely radiately striate. Surface of the valve, except for the ridges, smooth. Anterior auricle long, prominent, with a deep sinus. Posterior auricle small; both with strong elevated lines of growth, which rise into scales on the 8 or 9 fine ribs with which the anterior auricle is furnished. Hinge line straight, smooth. Inside of the valve polished, furnished with 21 rounded, mdiating ribs, with traces of others intercalated near the margin; nodulous or swollen at the more prominent ridges of growth and at the margin.

"'Upper [or left valve similar, inside; anterior auricle shorter, not so deeply sinuated. Valve more convex than the under one, and a little larger. Dorsal areas finely granulate. smooth; half wa}' toward the margin the stria; of increase become more conspicuous, and about 35 pseudoribs iliate toward the margin. These are formed by the elevation of the concentric lines of growth like ruflles, in such a way that the edge of one fluting of the ruflle overhangs the beginning of the next, and so on. These are very fragile, and when broken away show the nearly smooth surface of the valve underneath, without any true rib at all. Faint ribs are intercalated between the pseudoribs toward the margin."

19.5 mm.; long. 19.5 mm.; hinge line 9 mm.; diam. 5 mm.; umbonal angle 100.

This beautiful little deep-sea form is distinguishable from the other small PectinidHf of a like habitat by its internal lirae and the lack of radiating sculpture on the right valve. Its nearest allied species in the Pacific coast waters is P, davidwnl which, so far as known, is confined to the deep waters west of certain parts of Alaska.

P. alakensh is found living, and is also preserved in some of the Pleistocene deposits of Alaska and Vancouver Island. No record has as yet been made of it in the fossil state in any of the Pleistocene deposits of California. (See P. rivers, pp. 126-127.)

Living. Bering Sea to Panama Bay, usually in deep water (Dall). Pleistocene. Various pointe in Alaska (Dall); Point Holmes, Comox, Vancouver Island (W. Harvey; C. F. Newcombe; Dall).

Recent Pectens.

[Those knovm ouly in the recent fauna of th<! west coast.]

Pecten (Pkcten) excavatus Anton. PI. XL VI, figs. 1, la, and \h.

1835. Pedm dentatus C. B. Sowerby, Proc. 55ool. Sch!., 1835, p. 109; The. Conch., vol. 1, pt. 1, 1842, p. 49, pi. 15, figs. 105-106; not Pecten dtntntus J. Sowerby, Min. Conch. Gt. Brit, vol. 6, 1829, p. 143, tab. 574, fig. 1.

1839. Pecten excavatus Anton, Verzeichniss der Conchy lien, 1839, p. 19, No. 710 (erroneously reported from China).

Recent Pectens. 135

1845. Peclen excaratus Anton, Philippi, AbbiM. und Beschr. Conchyl., vol. 1, p. 201, Pecteii, p\. 2,

fig. 1, 1845 (also erroneously reports this species from China).

1846. Peclen excarntuH Valenciennes, Voy. Venus, pi. 19, fi. 1.

1853. Vola (ientata Sower]>y, H. and A. Adams, Gen. Kec. Moll., vol. 2, 1853, p. 554.

1863. Janira dental Sowerby, Carpenter, Brit. Assn. Re[)t., 1863, p. 645.

1869. Janira dadntn Sowerby, (iabb, Pal. Cab, vol. 2, 1869, p. 104.

1888. Pecten ( Vola) denUitnn Kiister and Conch. -Cab., vol. 17, pt. 2,

und Pecten, sp. 112, j). 155, taf. 44, figs. 1 and 2. 1888. Janira duntata Sowerby, Cooper Seventh Ann. Kept. Cal. St. Min., 1888, p. 244, (P. steamsii

in part). 1897. Pecten dentatus Sowerby, Verrill, Trans. Conn. Acad. Sci., vol. 10, p. 57. 1903. Pecten [Pecten) dentatus Sowerby, Arnold, Mem. Cal. Acad. Sci., vol. 3, p. 104, pi. 12, figs.

1 and

— Shell averaging about 70 millimeters in altitude, slightly longer than high, inequivalve, rhino-convex, equilateral, and with more .or less coarsely serrate margins; sides concave above. Right valve very convex, the disk near the apex projecting above the hinge line; ribs 22 or 23, evenly convex, much broader than high, and separated by interspaces which have only the importance of impressed lines; surface smooth exce])t for incremental lines which loop down ward on the tops of the ribs; hinge line greater than one-half length of disk; ears equal, convex, recUingularly truncated; anterior with two or three obsolete radiating ridges, and concentric sculpture; posterior generally with concentric sculpture only. Left valve concave, ornamented by 22 or 23 prominent, rather narrow, squarish. Hat-topped ribs, which are sometimes longitudinally faintly sulcated or ridged; interspaces slightly wider than ribs, flat- bottomed, and each containing a prominent, rounded intercalary riblet; surface sculptured by numerous fine, sharp, regular concentric lines, which appear most prominent in the spaces ])etween the ribs and riblets; ears equal, concave, laterally rectangular and sculptured by fine, sharp, incremental lines and two or three more or less prominent radiating ridges. Color salmon to salmon -pink, the left valve being the darker.

Dimensions, — Alt. 05 mm.; hinge line to ventral margin 59 mm.; long. 67 mm.; hinge line 35 mm.; diameter 25 mm.; umbonal angle (left valve)

This is the living representative of a genetic group which comprises P. keen P. ViKjdesi and P, exvavatHs, Beginning with the oldest in the series, P. I'eepi and advancing chronologically, the right valve becomes more convex, the lateral areas, which in l-cepi are very broad, narrower, the ribs become more numerous, narrower, and higher, the intirspaces correspondingly narrower, the hinge line relatively longer, and the ears more curved.

P, i.cca rains is of the same shape as the Japanese species P. laqueatus Sowerby, which has fewer, but squarer, broader ribs on the right valve. This last species has been reported from the Tertiary of Japan by Doctor Brauns in his Cleolog}' of the Environs of Tokio.'* P, hujieatu has been erroneously cited by Keeve from California'' (Dall).

Cooper mistook the flat valve of P, stearnsii for P, ejcavatun and labeled a specimen in the State Museum collection at the University of California,

a Mem. Univ. Tokio. No. 1. 1881. p. 48, pi. 7. fig. 31.

126 Tertiary And Quaternary Pecten8 Of California.

somewhat obliquely produced; margins sharply sermte; sides quite concave Right valve with 19 to 21 squarish, close-set, smooth ribs, which, in the adult, flatten out and have sloping sides near the periphery of the disk; interspaces very narrow and channeled; whole surface of disk sculptured by obsolete, wavy lines of growth; hinge line about two-thirds length of disk; ears in length, separated from disk a prominent groove posteriori} and small ridge anterior}-; anterior ear with 4 rather faint i-dials, and numerous tine, imbricating incremental lines; byssal notch deep, its upper side being about parallel with the hinge line; posterior ear with delicately curved extremity, and ornamented by fine incremental lines, and also on the lower half by faint radials. Left valve darker colored than right, and with the ribs narrower, flat-topped, and having sloping sides; interspaces wider, and covered both on the bottom and sides by tine, sharp, concentric lamellne; ears as in the right valve, except that the anterior one is not so conspicuously notched. Hinge strong, the pair of cardinal crura in the right valve being exceedingly well developed. Color patterns from light to dark brownish red.

DimtfttHlonH. — Alt. 40 mm.; long. 47 mm.; hinge line 32 mm.; diameter 38 mm.

This typical form is characterized by its great and regular convexity, broad ribs, and strong hinge. Type from (iulf of California.

Found living from the (lulf of California southward to Panama; in the Pleistocene farther north. Erroneous!} reported from the Philippines by Sowerln.

Living. Gulf of California to Panama (Sowerby, Carpenter, Button); St. Elena, off western coast of Colombia, South America (Sowerby).

Pleistocene. San Pedro; San Diego; Lower California (Hemphill, Stearns, Orcutt); Ventura; San Pedro; San Diego (Arnold); Springville, Ventura (Bowers).

Pliocene (0- Cholas Valley, near San Diego (Stearns).

Pecten (Propeamusium) rivers n. sp.

PI. XLIV, figb. 8 ami 9.

DeHC7'ipt!o7i. — Shell averaging 14 millimeters in altitude, about as long as high, circular in outline, equilateral, compressed, white, tmnslucent: margins smooth. Right valve compressed; surfa<'e smooth except for numerous very tine, regular, imbricating lamellae; hinge line one-half hnigth of disk: ears distinctly separated from disk by impressed line, subequal in length; the anterior arcuate in front and with about 12 sube(|ual prominent radials and numerous tine, regular, imbricating, incremental larnellas the posterior slightly oblicjuely truncated and sculptured similarly to the anterior, except that the radials are nearl} obsolete; byssal notch of medium prominence. Interior of disk smooth until an altitude of 15 millimeters is reached, when about 20 to 22 small, rounded, radiating ribs appear and continue to the periphery3\ Left valve somewhat more convex than the right, and ornamented externally bv numerous unefjual, prominently imbricated ribs, the alternate ones being intercalated between slightly larger ones; whole surface sculptured fine imbricating lainellse;

128 Tertiary And Quaternary Pectens Ob' California.

1888. Jaiiira Hinds, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 244 (/'. hnnphilll and

/'. steanxm in part). 1898. Pectm (JWten) diegenm Dall, Trans. Wagner Free Inst. Sci., vol. 8, pt. 4, 1898, p. 710.

1903. Pecten diegeims Dall, Arnold, Mem. Cal. Acad. Sci, vol. 3, 1903, p. 106, pi. 12, fip. 5.

1904. Pertet) dieganiHist Dall, Keep, Wct. Am. shells, p. 39.

Descrijdiov. — Shell averaging about 60 iiiilliniet<?rs in altitude, longer than high, inequivalve, plano-convex, or nearh .so, equilateral and with smooth margins: base evenly rounded; sides slightly concave above. Right valve somewhat convex (more pronounced near the umbo), and ornamented by about 22 or 23 prominent T-railshaped ribs, flattened, and generally longitudinally ridged or sulcateil on top, which overhang deep, narrow, flat- bottomed interspaces; whole surface sculptured by numerous flne, sharp, incremental lines; hinge line slightly less than one-half length of disk; ears equal, slightly convex, rectangularly truncated, sculptured by fine, sharp, incremental lines; anterior ear with small byssiil notch. Left valve flat or nearly so, generally concave near apex, ornamented by 21 or 22 prominent, narrow, convex-topped ribs, which are separated by concave- bottomed interspaces about equal in width to the ribs; whole surface promjntntly sculptured by numerous regular, fine, sharp, concentric, raised lines; ears concave, convexly truncated, and ornamented by the same concentric sculpture as the disk. Color, red and reddish brown, the left valve always being much darker than the right.

58 mm.; long. mm.; hinge line 2U mm.; diameter 18 mm.: umbonal angle (left valve) 95.

This species is distinguishable from its nearest relative, and probable precursor, Htearnsli b}- the smaller number and greater height of its cfm/fO),if!t) ribs, and relatively somewhat longer hinge line. The ribs of dnyeiMls have sometimes as many as three longitudinal sulci. Mrs. Oldroyd has two specimens taken from fishermen's nets at San Pedro, which measure over 150 millimeters (6 inches) in length, and are exceptionally high colored for this species.

Living. Monterey (Button; Mrs. Lambert and others); San Pedro (Oldroyd; Raymond); Catiilina Island, 10 fathoms (Arnold); San Diego (Raymond). (In all cases dredged.)

Pleistocene. San Diego (Hemphill).

Pecten (Nodipectex) subnodosus Sowerby.

PI. LII, lig. 1; PI. LIII, figs. 1 and la.

1835. Pecten mbiodoBUS yferhy Pnw;. Zool. Soc., 1835, p.

1842. Pecten mhnipiiosmoyfQrhy, Thes. Conch., vol. 1, pt. 1, 1842, p. 112, pi. 15, lig. 97.

1852. Pecten mhnodosm Sowerby, Reeve, Conch. Icon., vol. 8, Monog. (reniis Pecten, Nov., 1852, pi. 4,

fig. and sp. 20. 1867. Pecten intermedius Conrad, Am. Jour. Conch., vol. 3, 1867, p. 7 {Ude Dall, 1898). 1888. Pecten snbnodosus Sowerby, Kiister and Kobelt, Conch. -Cab., vol. 17, pt. 2, Spondylus und Pecten,

no. 71, p. 112, taf. 32, fig. 3.

1897. Lyropecten 8nbn<)doiu< Sov/erhyt Verrill, Trans. Conn. Acad. Sci., vol. 10, p. 64.

1898. Pecten {Nodipecten) mhnodosns Sowerby, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898,

p. 710.

Pleistocene Pecten8. 129

DeHcription. — Shell avemging about 110 millimeters in altitude, slightly broader than high, subequilateral, of medium thickness, somewhat ventricose, and with margins finely serrate; base regularly rounded; sides sloping and nearly straight. Right valve slightly less ventricose than left, with about 9 or 10 broad, flat, subequal ribs; interspaces subequal, with slightly rounded bottoms; whole surface sculptured by numerous (averaging about 7 on each large rib) radiating riblets, whose surfaces and interspaces are crossed by numerous fine, wavy liruhe of growth; several faint undulations are also generally noticeable on the disk; hinge line slightly longer than one-half length of disk; anterior ear about one and three-eighths times the length of the posterior, arcuate in front, and ornamented by several prominent radiating riblets and fine, sharp, incremental lines; byssal notch not very prominent; posterior ear rectangularly truncated and sculptured similarly to anterior. Left valve resembling the right except that it is slightly more ventricose and the ribs are ornamented by more or less elevated, hollow nodes, those on the alternating ribs being the more prominent.

Dimenshm, — Alt. 112 mm.; long. 120 mm.: hinge line 66 mm.; diameter 45 mm.

Doctor Dall is of the opinion that there is little reason for separating this form from the P, nodosm of the Antilles, although he says the latter is general' thinner, and has the nodosity more pronounced.

A fragment of a left valve of a variety of P. suhnodmuf< from the upper San Pedro formation (Pleistocene) of Deadman Island, San Pedro, has 17 ribs whose sides are concavely excavated, thus giving them a somewhat T-shaped cross section. The middle rib and the fourth rib on each side of it are very prominent, while the other ribs are smaller. Sculpture as in typical P. sribnod/mm.

The specimen figured is a living shell from the western coast of Mexico, and is now in the collection of the department of geology, Leland Stanford Junior Tniversity.

Living. Cyoast of Lower California to Ecuador and the tropical shores of South

America (Carpenter). Pleistocene. San Pedro (A. A. Wright; Arnold): Cerros Island and other points on

the coast of Lower California (Dall). Pliocene. Temescal Canyon, SanUi Monica Mountains, Los Angeles County (Rivers).

Pkitkn (Chlamys) LATiAumxi s Conmd var. cekkitensis n. var.

PI. XLVI, firs. Hand 7.

1908. Perten {('hhniiij.<) latmnritnn \av. frtufdh Arnold, Mem. C'al. Acad. Sci., vol. 3, pt. 2, 1903, p. 112, 12, S; not IWien fnujiUs Jeffreys, Ann. and Mag. Nat. Hist, 4th ser., vol. 18, 1876, p. 424.

— of same jeneral type as latianritiH, More compressed and much thinner: ribs to nine, very low and rounded, with shallow, rounded interspaces; surface smooth, the concentric sculpture being nearlv obsolete; hinge long; ears rather sharply pointed. 17260— No. 47—06 9

Tertiary And Quaternary Pkctkns Of California.

D'TTvUjfionji. — Alt. 26 iniu.; lon. 26 nun.; hine line 25 min.; diameter 7.8 mm.

This variety is distinguishable from DalFs variety, AcvVWm, whioh it re?ieinble.s, f.iy having a longer hinge line and generally more pointed ears.

F"ound associated with the typical species in the Pleistocene (upper San Pedro foruiation) at San P(*dro and San Diego.

PleiUx-ene. San Pedro; San Diego (Arnold).

Pectten (Chlamys) LATiAURiTrs Courad var. delosi n. var. PI. XL VI, figs. 9, 10, and KVi.

— Shell averaging about 12 millimeters in altitude, slight' longer than 'high, subequivalve, both valves only slightly convex, inequilateral, the disk oblique to the hinge line and somewhat produced posteriorly; sides marly straight; margins rough. Right valve with about 16 prominent smooth- s<]parish ribs; interspaces wider than the ribs, and ornamented on the bottom and sides by numerous prominent, regular, equidistant, imbricating, in<'remental lamelhv; hinge line as long as, or slightly longer than, the disk; ears equal in length; anterior ear long and narrow, sepamted from the disk by a deep, sharply defined, byssal notch and sculptured by five or six prominent radials and nunuTous, regular, im))ricating, incremental lamella*. Left valve similar to right except that the ribs are slightly narrower and the incremental lamellie extend the tops of the ribs in some ears acutely pointed and sculptured by num(;rous regular, sharp lamella;; anterior somewhat shorter than the posterior and with four major and as intercalarv radials; posterior with four or five radials.

Dhuetmanii, — Alt. 12 mm.; long. 12.5 muh; hinge line 13.5 nun. ; diameter 8.5 nmL; umbonal angle lH.

This beautiful little lecUn one of the smallest found in our fauna, is characterized by its extremely long hinge line* and prominently lamellated surface. It is distinguishable from the typiwil latHiarltm and varieties, with which it is allied, by its longer hinge line and prominently lamellatc.d interspaces.

The living sjx'cimens have the ribs more prominently lamellated above than the fossil forms. var. (dont appears to occupy somewhat deeper (and consequently colder) water than the* typical form. The specimens of P. latiaurifam found in the Santa barbara and regions to lean strongly toward this variety.

iMoHt has been found fossil so far only in the lower San Pedro formation (Pleistocene) at Deadman Island, near San Pedro. Types now in the collection of Arnold, the writer's father, after whom the species is named. Living specimens dredged in 15 fathoms at Catalina Island.

Living. Santa Catalina Island, Los Angeles County, in 15 fathoms (Arnold); Santa

Barbara (Dall); Monterey (Button). Pleistocene (lower San Pedro formation). Deadman Island, San Pedro (Arnold).

n

Pleistocene Pectens. 181

Pectkx (Chlamys) i.ATiAURiTUS Coiirad var. fucicolus Dall. PI. XLVI, figH. 1898. Pecten latkinntm var. Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p 710.

of same general type as latlaurltm. Moderately compressed, smooth, coneentrie sculpture obsolete; ribs low, rounded, wide, entire; hinge line shorter than in the type, and without any sinus between the posterior ear and the disk.

— Alt. 80 nmi.: long. 31 mm.

'This form lives attached by the byssus to the gijint kelp of the Californian coast, and the absence of shock, due to the floating situs, is probably correlated with the obsolescence of the ribs and the posterior sinus. Intergradations with the type are not at all rare/' (Dall, 1898.)

kaN(;k.

Living. Santa Barbara, south to Cape St. Lucas (Dall). Pleistocene. San Pedro; San Diego (Dall; Arnold).

Pecten (Chlamys) latiauritus Conrad var. monotimeris Conrad.

PI. XLVI, figs. 4, 5, and 5.

1837. Pecten monotimeris CoiiTiidi, Jonr. Acad. Nat. 8d. Phila., vol. 7, 1837, p. 283, pi. 18, fig. 10.

1863. Pecten monotimerin Conrad, Brit. Assn. Rept., p. 64b.

1888. Pecten monotimeris Conrad, K lister and Kobelt, Conch. -Cab., vol. 17, pt. 2, Spondylas und Pecten,

No. 257, p. 276, taf. 72, tigs. 7 and 8.

1888. Pecten latiavritu Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 257 (in part).

1892. Pecten montitimeris Conrad, Keep, West Coast Shells, 1892, p. 167, fig. 140.

1897. Pecten (Leptopecten) mmiot imcriii Conmd, Verrill, Trans. Conn. Acad. Sci., vol. 10, j). 69.

1898. Petien latianrita var. monotimeris Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898,

p. 709.

1903. Pecten (Chlami/A) latidurituH Con. var. momjtinitri. Conrad, Arnold, Mem. Cal. Acad. Sci., vol. 8,

pt. 2, 1903, p. 112, pi. 12, figs. 4 and 4n.

1904. Pecten Idliauritux var. inonotinwris Conrad, Kecj), West Am. Shells, i>. 40, fig. 20.

JAsny'jjfioji. -Shell of the treneral type of P. latlnurlfiis hut more oblique, inflated, and markedly shorter, with smaller ears; ribs generally prominent and squarish, and interspaces channeled; incremental sculpture sometimes very pronounced.

Dlmensvnts,— lCMnm.; long. 19 mm.; hinge line mm.; diameter IMnm.

This variety is characterized hy its ventricosity, vvell-delined ribs, and rclatively short disk and hing<' line. var. numnt'nin rlf< is very connnon at Los Cerritos Hill, near San Pedro, but is much rarer in the other Pleistocene localities than the typical hitidnriffis.

Found in the fossil state in tlu upper San Pedro formation (Pleistocene); also occurs recent.

Living. Fort Point, San Francisco (Button); Santi Barbara to San Diego (Dall). Pleistocene. Santa Barbara; San Pedro (Dall); San Pedro; San Diego; Ventura (Arnold); Newport, Orange County (No. 11895, C. S. M. B.) (Watts).

182 Tertiary And Quaternary Pecten8 Of California.

Pecten (Plagioctenium) circularis Sowerby var. .aiQUisuLCATUS (/carpenter.

PL L, figs. 1, la, and lb; alno text fig. 1, p. 45; fig. 2, p. 46.

1863. Pecten [rentricoms var.?] /rw/nf/cafu* Carpenter, Brit. Assn. Rept., 1863, p. 646.

1865. Pt'dm (?var.) ivqvimlcatug Carpenter, Ann. and Mag. Nat. Hist., 3d ser., vol. 15, 1865, p. 179.

1869. Pecten rmtricomn Gabb, Pal. Cal., vol. 2, 1869, p. 104.

1888. Pectm nquimlcaUis Carpenter, Kuster and Kobelt, Conch. -Cab., vol. 17, pt. 2, Spoudylus und

Pecten, no. 249, p. 269, taf. 71, figs. 1 and 2. 1888. Pecten rentrieosus CoopcT, Seventh Ann. Rept. Cal. St. Min., 1888, j). 258 (Quatemar)' reconl

only).

1892. Pectm icqnimlcatus Carpenter, Keep, West Coast Shells, 1892, p. 166, fig. 139.

1893. Pfcteii a'TutMc/ca/iw Carpenter, Williamson, Proc. U. 8. Nat. Mus., vol. 15, for 1892, p. 193. 1898. Peden {rentricfjmis \&t.') {vquisulcatus Carpenter, Dall, Tran<. Wagner Free Inst. Sci., vol. 3, pt.

4, 1898, p. 711. 1898. Pecten {Phfjiocteiiium) Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 710 (in part).

1902. Pecten Hqumdcaltui Carpenter, Willianinon, Bull. So. Cal. Acad. Sci., vol. 1, No. 5, May, 1902,

pj). 51-64, pis. 4-6.

1903. Pecten (Plaffioctenknn) centricontnt* Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 114, pi. 11, figs.

1903. Peden (Plagioctenium) nenwmi Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 113, pi. 11, tigs. 1

and la (a yomig shell) .

1904. Peden xquimlcatus Carpenter, Keep, West Am. Shells, p. 39, tig. 18.

Description. — Adult shell averaging alwut 75 millimeters in altitude, much longer than high, the anterior portion of the disk being obliquely produced; sides somewhat concave above; shell rather thin; margins serrate. Right valve with 20 to 22 modorateh' prominent, flat-topped ribs separated b}' much narrower, flatbottomed interspaces; lateral areas about as wide as two normal ribs; whole surface of disk sculptured b}' tine, ship, looped, incremental lines; hinge line about fiveeighths length of disk; ears equal in length; anterior ear sculptured with fine concentric lines and 7 or 8 more or less prominent i*dials; byssal notch deep And sharply defined; posterior ear rectangularly truncated, and sculptured by concentric lines and obsolete radials. Left valve with narrower ribs, which have more sloping side.s, and more prominent lamella? of growth in the interspaces; interspaces broader; ears similar to those of right valve, except that the posterior is not sharply notched. Oolor, white to light reddish yellow blotched with shades of reddish brown, the left valve being always perceptibly darker colored than the right.

DiiiumsUm. — Alt. 72 mm.; long. 83 mm.; hinge line 51 mm.; diameter B() mm.; umbonal angle 100.

This variety is more or less variable in regard to its convexit}', obliquity, relative width and height of ribs, and coloration. In the young specimens the right valve is perceptibly more convex than the left; the ribs are relatively much squarer and more prominent, the interspaces correspondingly narrower and deeper, the hinge line comparatively longer, and the umVwnal angle appears to be less, than in the adults. The tendency of the ribs to flatten out and the concentric sculpture to ]>ecome more irregular and rough as the shell grows older is evident to a greater or le,ss degree in nearly all of the specimens examined.

Pleistocene Pectens. 133

The Pleistocene shells, as a rule, are more convex (the right valve noticeably more so than the left), somewhat less oblique, and the ribs are slightly broader and more compact, than the living specimens. The 3-oung of P, var. fequiHuleatnH have the characteristics of the Pleistocene form and are scarcely distinguishable from the young of P,

P, var. iVfjiUHultuitufi varies from the typical P, rlrculartH of the (iulf of California and west Mexican coast fauna by ib larger size when adult, Hatter and thinner disk, narrower ribs, and more subdued coloration. These two forms seem to have separated during the Pleistocene, the living shells not appearing to give a satisfactory connection, while a large series of Pleistocene sjxcimens shows an obvious gradation. Doctor Dall p. in speaking of the influence of environment upon the Pectens, thus the relation between P. cinmlarlH and P. var. Hifjuiu/eatttx: 'As in mammals and birds, the same species in the northern part of its [Pecten] range is larger than in the south, unless it is a distinctively tropical species. But in color the rule is reversed, the southern specimens being lighter and more brightly tinted than the northern ones in the same species. The specimens which live in deep water and swim actively are usually thinner shelled and smoother, while those which inhabit the lagoons are heavier, have more conspicuous concentric, sculpture and more solid shells. These differences are very marked in our common east coast trradlans of which P, d/'s/ocafu Say is the southern lagoon form; and {parallel differences appear in the similarly related rentrlcoiu P, drcuhn*!] and its variety iequiHulcatu'i on the Pacific coast

P, var. iAiumiJcatm ranges from th( Pleistocene to the Recent fauna.

Rangk.

Living. Santa Barbara to Pacific side of California.

Pleistocene. San Pedro; San Diego; Lower California (Hemphill, Stearns, Orcutt);. Ventura: San Pedro; San Diego (Arnold); Springville, Ventura County (Bowei*s).

Pecten (Pkopeamisium) alaskensis Dall.

PI. I.I II, liH. 2, 2, and 8.

1872. IWten PseudttrtvmiKm/) Alaakeiinitt Dall, Am. Jour. Conch., vol. 7, 1872, p. 155, pi. 18, tip. 4.

1886. Perhn Propfnmushun) nla.sk'en)*h Dall, Bull. Muh. Coinp. Zool., vol. 12, no. 215, pi,

1887. Not IV'cfen alaskensis Whiteaves, Trans. Roy. 8oc. Canada, 4, set*. 4, 1887, p. 119 (=P.

rancourerin'iH Whiteavos, 189.S).

1888. Pecten alaskensis Dall, KolHlt, Concli.-Cal)., vol. 17, pt. 2, uiid Pecten,

sp. 220, p. 245, taf. <)4, fijs. 7, 8.

1889. Perhn ( Pmpeamnxinm) alaskeiisis Dall, Hull. V. S. Nat. Mus., No. 'M, 1889, pi. 5, ii. 7, 7a. 1898. Perten Alaskensis Dall, Ncwconibe, Kt'pt. on Mar. Sh. Hrit. Columbia, Bull. Nat. Hint. Soc.

Brit. Columbia. 1S98, art. 5, p. 5:{. 1895. Perten ( Psendaniuinni) Alaskensis Dall, Taylor, Trans. Soc. Canada, 2d ser., vol! 1, 1895, sec. 4, p. 27.

1897. Antasinni Propeantnsinni) Alaskensis Dall, Verrill, Trans. Conn. Acad. Sci., vol. 10, p. 65.

1898. Peeten Prapeama.inni) alashnsis Dall, Trans. Warner Free Inst. Sci., vol. 8, pt. 4, 1S98, p. 711.

The original description is as follows:

— ''Shell nearly equilateral, inequi valve, flesh color, with a blush of salmon <*olor on the lunbo of the* superior valve. Internal' white, the salmon color

134 Tertiary And Quaternary Pectens Of California.

showing through the valve. Shell suborbiciilar, barring the auricles, which are wide and prominent. Lower [or right] valve flattened, 0.1 inch (2.5 millimeters) smaller than the upperone; sculpture of fine, close, equal, concentric ridges, sharply defined and separated by narrow non-canaliculated grooves. Valves covered with a fine velvety epidermis, ashy and very finely radiately striate. Surface of the valve, except for the ridges, smooth. Anterior auricle long, prominent, with a deep sinus. Posterior auricle small: both with strong elevated lines of growth, which rise into scales on the 8 or 9 fine ribs with which the anterior auricle is furnished. Hinge line straight, smooth. Inside of the valve polished, furnished with 21 rounded, radiating ribs, with tnices of others intercalated near the margin; nodulous or swollen at the more prominent ridges of growth and at the margin.

*'lpper [or left] valve similar, inside; anterior auricle shorter, not so deeply sinuated. Valve more convex than the under one, and a little larger. Dorsal areas finely granulate. Umbo smooth; half way toward the margin the stria; of increase become more conspicuous, and about 35 pseudoribs radiate toward the margin. These are formed by the elevation of the concentric lines of growth like ruffles, in such a way that the edge of one fluting of the ruflUe overhangs the beginning of the next, and so on. These are very fragile, and when broken show the nearly smooth surface of the valve underneath, without any true rib at all. Faint ribs are intercalated between the pseudoribs toward the margin."

DimtmlonH.—AXi. 19.5 mm.; long. 19.5 mm.; hinge line 9 mm.; diam. 5 mm.;

umbonal angle 100.

This beautiful little deep-sea form is distinguishable from the other small Pectinidn of a like habitat by its internal lirse and the lack of radiating sculpture on the right valve. Its nearest allied species in the Pacific coast waters is davldwni which, so far as known, is confined to the deep waters west of certain part of Alaska.

P, alakensts is found living, and is also preserved in some of the Pleistocene deposits of Alaska and Vancouver Island. No record has as yet been made of it in the fossil state in any of the Pleistocene deposits of California. (See P, rivers, pp. 126-127.)

Range.

Living. Bering Sea to Panama Bay, usually in deep water (Dall). Pleistocene. Various points in Alaska (Dall); Point Holmes, Comox, Vancouver Island (W. Harvey; C. F. Newcombe; Dall).

Recent Pectens,

[Thofle known only in the recent fauna of the west coajit.]

Pecten (Pecten) excavatus Anton. PI. XLVI, figs. 1, la, and l/>.

1835. Pecten dentcUus C. B. Sowerby, Proc. Zool. Soc., 1835, p. 109; Thes. Conch., vol. 1, pt. 1, 1842, p. 49, pi. 15, figs. 105-106; not Pecten dcntatus J. Sowerby, Min. Conch. Gt. Brit., vol. 6, 1829, p. 143, tab. 574, fig. 1.

1839. Peden excavatus Anton, Verzeichniss der Conchylien, 1839, p. 19, No. 710 (erroneously reported from China).

Recent Pectens. 135

1845. Pecten fxcavatus Anton, Philippi, Abhild. unci Beschr. Conchyl., vol. 1, p. 201, Pectett, p\. 2,

fig. 1, 1845 (also erroneously reporti this species from China).

1846. Pecten ej-raratus Valenciennes, Voy. Venus, 184(), pi. 19, fig. 1.

1858. Void (lentata Sowerby, II. and A. Adams, <ien. Reo. Moll., vol. 2, 1853, p. 554.

1863. Jaiiira deniaUt Sowerby, Carpenter, Brit. Assn. Rept., 1863, p. (>45.

1869. Jamra deutata Sowerby, (labb, Pal. Cal., vol. 2, 1839, p. 1()4.

1888. Pecten (Tola) deulains iowktrhy, Knster and Conch. -Cab., vol. 17, pt. 2, S})ondylus

und Pecten, sp. 112, j). 155, taf. 44, figs. 1 and 2. 1888. Janirn dentatn Sowerby, Cooper Seventh Ann. Rept. Cal. St. Min., 1888, p. 244, {P. stearnsn

in part). 1897. Pecten dentatus Sowerby, Verrill, Trans. Conn. Acad. Sci., vol. 10, j>. 57. 1903. Pecten (Pecten) dentatuH Sowerby, Arnold, Mem. Cal. Acad. Sci., vol. 3, p. 104, pi. 12,

1 and It/.

Desalt ption, — Shell averaging about 70 millimeters in altitude, slightly longer than high, inequivalve, plano-convex, equilatenil, and with more .or less coarsely serrate margins; sides concave above. Right valve very (convex, the disk near the apex projecting above the hinge lino; ribs 22 or i3, evenly convex, much broader than high, and separated by interspaces which have only the importance of impressed lines; surface smooth except for incrementiil lines which loop down ward on the tops of the ribs; hinge line greater than one-half length of disk; ears equal, convex, rectiingularly truncated; anterior with two or three obsolete radiating ridges, and concentric sculpture; posterior generally with concentric sculpture only. Left valve concave, ornamented by 22 or 23 prominent, rather narrow, squarish, Hat-topped ribs, which are sometimes longitudinally faintly sulcated or ridged; interspaces slightly wider than ribs, flat-bottomed, and each containing a prominent, rounded intercalary riblet; surface sculptured b}' numerous fine, sharp, regular concentric lines, which appear most prominent in the spaces between the ribs and riblets; ears equal, concave, laterally rectangular and sculptured by fine, sharp, incremental lines and two or three more or less prominent radiating ridges. Color salmon to salmon -pink, the left valve being the darker.

tensions, — Alt. 05 mm.; hinge line to ventral margin 59 mm.; long. 67 mm.; hinge line 85 mm.; diameter 25 mm.; umbonal angle (left valve) 98.

This is the living representative of a genetic group which comprises keen., rfu/def<!, and P, e.''rarafu.s. Beginning WMth the oldest in the series, jP. h?e/H\ and advancing chronologically, the right valve becomes more convex, the lateral areas, which in hvpi are very })road, become narrower, the ribs become more numerous, narrower, and higher, the interspaces correspondingly narrower, the hinge line relatively longer, and the ears more curved.

i,vaivatuH is of the same shape as the Japanese species P. laqxieatun Sowerby, which has fewer, but sifuarer, broader ribs on the right valve. This last species lias been reported from the Tertiary of Japan by Doctor Brauns in his Geology of the Pnvinms of Tokio." P. JiUiueatHi< has been erroneously cited by Keeve from California''' (Dall).

Cooper mistook the flat valve of P. stearnHii for P, e./'caivittw and labeled a specimen in the State Museum collection at the University of California,

nMcm. Univ. Tokic. No. 4. 1881. p. -18. pi. 7. flf?. 31.

136 Tertiary And Quaternary Pecten8 Of California.

Berkeley, ''Janlra dentuta Sby, San Pedro, Quaternary." The specimen undoubtedly came from the Pliocene of Deadman Island, instead of from the Quaternary.

P. e.rcamtHM is known only as living, and so far has been noted only from the Gulf of California, where it is a very common species in some localities.

ran(;k.

Living. Gulf of California (Sowerby; Valenciennes; Cai-penter; Button, and others).

Pecttex (Chlamys) iiASTATUS Sowcrby var. albidus Dall n. var. PI. LIT, figs. 2 and 24i. 1904. Pecten ( Chlamifs) hericius var. aibidm* Dall, MS.

Description. — Shell of the same shape and geneiul appeamnce as P. var. hetius but smaller when adult, being only about 45 millimeters in altitude. The sculpture on the right valve consists of numerous elevated, narrow, thread-like, imbricated riblets, which have the appearance of being grouped together in three or more unequal, equidistant, more or less convex fasciculi; the interspaces between the fasciculi are ornamented by riblets of equal prominence to those forming the fasciculi; anterior ear with about seven equal, prominently imbricated i-dials; posterior ear short and with radial and imbricating sculpture; basal notch quite prominent. Left valve similar to right, but with the fasciculi corresponding to the interspaces of the right valve, and consequently much narrower than the fasciculi of that valve. Color, white to very light pink.

DbneuHioiu. — Alt. 45 mm.; long. 40 mm.; hmge line XSs mm.; diameter 14 mm.

This variety is characterized by its broad, low fasciculi and light color. Type* No. 150207, U. S. Nat. Mus., from U. S. F. C. Sta. 3313, Iliuliuk Har])or, Unalaska, 68 fathoms, 42.7" bottom temperature.

Living. U. S. F. C. Stas. 3311, 3313, 3318, 3321, Bering Sea, in 54 to 85 fathoms (U. S. Fish Conmiission).

Pecten (x5<]quipecten) palmer Dall.

PI. L, figB. 2, 2a, 8, 3. 1897. Pecim paimeri Dall, NaiitiluH, vol. 11, No. 8, Dec, 1897, p. 85.

The original description is as follows:

Description, — " Shell thin, orbicular, compressed, equilateral, white to yellowish brown, with concentric or zig-zag narrow bands or flecks of dark rose color; 15 strong ribs rounded in the young, mesially keeled and longitudinally threaded in the

Recent Pecten8. 137

adult, sepamted by narrower clianneled interspaces, each Tvith a mesial thread; all crossed by lainellose, concentric, rather spar-sel}" distributed elevated lines; submargins and ears closely radially threaded with imbricated threads. Both valves similarly sculptured."

Dime7hHionH. — Alt. 47.5 mm.; long. 5H mm.; diameter about 20 mm. , This species is easily distinguishable by its flat, orbicular disk and pexjuliar sculpture. It is known only in the recent faunas, and is found near the head of the Gulf of California, from whence the type and several other valves were obtained by Dr. E. Palmer some yeiirs ago.

Living. Near head of Gulf of California (K. Palmer).

Pkcten (Pla(}Ioctenium) paucicostatus Carpenter.

PI. XXXIX, H'H. 3, 3</, and 4.

1863. Pecten pauclcostatiis Carpenter, Brit. Assn. Kept., 1863, j). 645.

1866. Pecten paucicoatatun Ann. anil Mag. Xat. Hist., 3d ner., vol. 15, 1865, p. 179. 1888. Pecten paucicodains KiiHter and Kobelt, Conch. -Cab., vol. 17, pt. 2, und Pecten, no. 9, p. 281.

Description, — Shell averaging about 35 millimeters in altitude, longer than high, subequivalve, modei'ateh- ventricose; thick-shelled; margins smooth. Right valve subequilateral, slight- more ventricose than the left; ribs 12 to 14, prominent, convex-topped, subangular; interspaces slightly wider than the ribs, somewhat rounded; incremental sculpture tine and regular, not looped; hinge line about fivesevenths length of disk; ears moderately prominent; anterior ear with about five prominent radiating ridges and numerous incremental lines; byssal notch prominent; posterior ear similar to anterior in sculpture, except that it is not quite so pronounced as in the latter. Left valve with prominent subangular ribs, slightly narrower than those of the right valve; interspaces correspondingly wider and flat-])ottomed; ears similarly sculptured to those of right valve.

DimenHumH, Alt. 84.5 mm. ; long. 37 mm. ; hinge line 25 mm. ; diameter 13 mm.

The specimen described is No. 15<)43, U. S. N. M. It is dark brown in color, with no patterns or This species is distinguishable from P, latiaurltiis and varieties by its much heavier shell, dark uniform color, shorter hinge line, and fine uniform lines. The type is labeled ''Santa Barbara'" by Jewett, but is umiuestionahly from the (nilf of California, as no species with its chamcteristics are known outside of the tropical fauna. Besides, Jewett was known to be quite careless regarding the localities of iiis

Living, (nilf of California (Jewett, Stearns).

138 Tertiary And Quaternary Pecten8 Of California.

Pecten (Pseddamusium) davidsoni Dall.

PI. L, figs 4 and 4a.

1897. Pecten Daridsoni Dall, Nautilup, vol. 11, No. 8, Dec, 1897, p. 86.

1902. Perfen Daridsoni Dall, Proc. U. S. Nat. Mus., vol. 24, 1902, p. 559, pi. 40, figs. 5, 6.

1904. Perten davidjfoni Dall, Keep, West Am. Shells, p. 41, figs. 21a, 216.

The original description is as follows:

— "Shell small, suborbiciilar, compressed, waxen white, the left valve with 21 rounded ribs, surmounted (when not worn oflf) continuous rows of minute subglobular scales, the interspaces wider, flat, and perfectly smooth, ears very small, the anterior with five or six imbricated radii; sculpture obsolete near the umbones; right valve sculptured with faint concentric impressed lines over the whole surface, and distally with numerous minute, obsolete, fine, scaly riblet: posterior ear transversely striated, very small, anterior one with four or five scah' radii, a well-marked sinus leaving an imbricated fasciole and no ctenolium. Interior polished, the left valve fluted internally in harmony- with the external ribs."

Dhnennon, — Alt. 14 mm.; long. 14 mm.; diameter 3.5 mm.

This little shell somewhat resembles P, externally, but lacks the i-radiating line internally, is smaller, and has faint radiating sculpture on the right valve, which is wanting in P.

This deep sea form is known only in the living fauna. The type (U. S. N. M., 107747) is from the Davidson Bank, Alaska, in 280 fathoms, green-mud bottom.

Ranoe.

Living. Davidson Bank, Alaska, 280 fathoms; north of Unalaska, in Bering Sea, 351 fathoms (U. S. Fish Commission).

Pecten (Pseudamusium) randolph Dall.

PI. XLVIII, figs. 2 and 2.

1897. Randolphi Dall, Nautilus, vol. 11, No. 8, Dec\, 1897, p. 86.

1902. Pecten Randolphi Dall, Proc. U. S. Nat. Mus., vol. 24, 1902, p. 559, pi. 40, tig. 2.

1904. randolph Dall, Keep, West Am. Shells, p. 41.

The original description is as follows:

Description, — "Shell small, thin, glassy, unseulptured, except by minute ''Camptcmectes'* striation which covers both valves, and more or less obscure concentric undulations which are most distinct on the right valve near the umbo, and in some specimens altogether absent; hinge straight and short, anterior ears distinct, posterior ears not defined by fold or sinus, outline suborbicular, valves compressed, especially the right one; right anterior ear with six small imbricated radii above, below a wide, transversely striated fasciole derived from a well-marked byssal sinus; ctenolium vith four or five functional spines."

DuaenHuma. — Alt. 27.5 mm.; long. 2H mm.; diameter 5 mm.

This species is the living representative of the group consisting of the three very closely allied, if not identical forms, P. peckhavii P. pedrodnu and P, randolph. The poor state of preservation of the fossil specimens precludes any definite state-

Recent Pectens. 139

ment as to their equivalence, but from the large amount of material examined it is clearly evident that the three are very closely relat(?d. jhckhami averages smaller than the other two and lias usually only four radials on the right anterior ear, while pedriKinua is the largest of the group and is general I3' much more prominent' undulated than the others. The three species are so nuu*h alike, at any rate, that with the usually ])oor state of preservation of the Miocene fossil forms it would impossible to make any detinite distinctions in 99 per cent of the cases that have fallen under the observation of the writer. This being true, it is (juite evident that the two forms, and jnckhami which heretofore have always considered diagnostic species of the Miocene, at once lose their value as agents of correlation. A further study of well-preserved fossil material, if anv is ever obtained, will undoubtedly tend to make clear the relations existing between the members of this very interesting little group.

The type of nmMphl (U. S. N. M., 107749) was dredged by the U. S. Fish Commission steamer AlhfftrosM off Destruction Island, Washington, in 510 fathoms tenipemture, F.

KA.NiiK.

Living. Bering Sea to West Mexico, in 225 to 1,(>()5 fathoms (LI. S. Fish Commission.)

Pecten (Pseudamusium) Dall var. tillamookensis n. var.

PI. XLVIII, lij. 3 and 8f/.

JJescrl//i, — Shell resembling raiuhdphi in outline and general characteristics. Disk ornamented by numerous more or less prominent, fine, radiating ridges, microscopic radiating strite, and incremental lines of varying prominence. The radiating ridges are narrow and thread-like, and appear to be more prominent anteriorly and near the lines of interrupted growth; the ribs are affected similarly to the disk by the interruptions in growth. The microscopic striai cover the whole surface of the disk and ribs and in a geneml way radiate from the umlx), but are seldom parallel to the ribs; on the portion of the disk and ear posterior to the umbo the stride are perpendicular to the lines of growth and are thus nearly parallel and not radiating. The right anterior ear lias from 6 to 12 prominently imbriaited radials.

Dime/hsanis, — Alt. 30 mm.: long. 30 mm.; hinge line 17 nun.; diameter 7 mm.

This variety appears to combine some of the characters of with rdndoJphi. having the prominent radial sculpture of the former and the relativel}' large, undulated disk of the latter; the ears in P, var. tUlamookenma are sculptured more nearly like the former, having from 1 to more radials than P, I'undolplii.

This variety generally occurs in deeper water, along the northwestern coast, than the typical form, being found at depths of from 400 to 800 fathoms.

The L'. S. N. M. 150233, is from off Tillamook Bay, Oregon, at U. S. F. C. Sta. 3346, at a depth of 78H fathoms.

Living. From north of Unalaska, 351 fathoms, to off Tillamook Bay, 736 fathoms. (U. S. Fish Commission.)

14( Tertiary And Quaternary Pecten8 Of California.

PbCTEX (PsEUDAMUSIUM) VAXCOUVKREN8IS WhiteavcH. PI. LI I, figs. 3 and :Vi.

Pirr. iinutw Dall (not Gould), Bull. Mus. Coinp. vol. 12, 1886, p. 216, pi. 5, fig. 4

Vajij-jii young of P. caurintm). IriT. PHcadnititutixmn) AlmkermV'YihSLX {not Dall), Trans. Roy. Sot'. Canada, vol. 4, set'.

4. for 1SW6. 1887, p. 119. ls?!tf*. iVlTTi rMt/rmti* Dall (not Gould), Bull. V. S. Nat. Muh., No. 37, 1889, pi. 5, fig. 4

yrmn P. cutrinu)*). I'W'l. Prtni Pfrtidamuiuin) Vaucouverennlff Whiteavefii, Ottawa Naturalist, vol. 7 (being vol. 9,

Trans. Cniawa Field-Nat. Club), 1893, p. 133, pi. 1, figs. 1, la. jHicj. Purudamwthnti ) VaruouverenmH Whiteaves, Bull. Nat. Hist. Soc. Brit. Co-

Iniiibia, 1893, art. 5, p. 53. ]<6. Pevdainusium) VanmufTrniJth Whiteaves, Taylor, Trans. Roy. 8oc. Canada, 2d ser.,

1, 1895, se<'. 4, p. 26. PrUi, nni*mrerfui WhiteaveH, Keep, West Am. Shells, p. 41.

The original description i-s as follows:

D':. — ''Shell small [averaging about 7.5 millimeters in altitude], equi val%'ed. (impressed lenticularly, both valves being equally convex, ovately subcircular in outline apart from the ears and rather oblique; valves extremely thin and fnigil*-. ininslucent and almost transparent, pale horn color with a alight3' yellowish hw. Ifeaks placed a little behind the midlength; hinge line straight and ver\- long; eari unequal in size, the posterior pair, which are smaller than the anterior, alike, indistinctly defined, and merging gradually and imperceptibly into the general i'on%-exit and marginal contour of that side of each valve; anterior ears large, sul>- triangular. prolonged laterally, and longer than high, distinctly defined, that of the left %'alve somewhat convex in outline above and concave below, that of the right %-alve with a deep and acutely angular byssal sinus at its base.

Surface marked by densely crowded and exceedingly minute, irregular, and rarely continuous, but, on the whole, i-radiating, simple or bifurcating raised lines, also by comparatively large, regularly disposed, and distant squamosa radii. In the center of each valve the minute and nonsquamose raised lines are essentially parallel to the larger squamose radii, but on the sides the former are disposed obliquely to the latter. The surface of the anterior ear of each valve is minutely cancellated with extremely minute raised lines, which are almost parallel to the hinge line, in addition to the coarser cross lines. The whole sculpture of the exterior of the test is far too minute to clear3' seen without the aid of a microscope or powerful simple lens, but under either of these a few faint concentric lines of growth are also visible.''

DuiuHHlitnH, — Alt. 7.5 mm.; long. 7.75 mm.; diameter 2.25 mm.

This beautiful little Pecten is easily distinguishable from the other members of the same group by its smaller size when adult, fine radiating lines of sculptui'e externally, and by its relatively longer hinge line.

Living. Sitka Harbor, 12 fathoms (Dall); Forward Inlet, Quatsino Sound (Dawson); Departure Bay (Taylor, Macoun): off San Pedro, Ios Angeles C<)unty, fathoms (Oldroyd); Avalon Harbor, Catalina Island, 15 fathoms (Arnold).

Descriptions Of Subgenera And Species. 141

Vxidkstifiable Pectexs.

PkCTKN CATILLIFORMIS

1856. Pe<:ten catilliforiniH Conrad, Pac. R. R. Rept., vol. 5, p. 329, pi. 9, fig. 83.

1888. catiWformiA Conrad, Seventh Ann. Rept. Cal. St. Min., for 1887, p. 257 (in

part). 1898. Peden catiWformix Conrad, Dall, Trans. Wagner Free Inst. 8d., vol. 8, pt. 4, p. 700.

OrUflntd dracripffo}) and notes, — Orbicular, plano-convex, with radiating Htrit and distinct rounded ribs: ears equal.

''This lare Perttm has such a general resemblance to P, madmmln Say, of the Virginia Miocene, that I have no doubt it existed at the same period, or at least after the Eocene. There is none such now living on the coast of California, and none in the Eocene, of this group of large pectens, which occur almost everywhere in the Miocene deposits of the Atlantic slope.

''Locality, — Ocoya Creek [Kern County

The t\"pe of this species was the internal cast of some large Lyropecten (?). probably allied io craflcarda or hoirersL According to Dall the type is unknown as the species was Conrad from drawings made b\' Prof. W. P. Blake. The figure in the Pacific Railroad Report is so poor and the description so meager that it is pro})able the species will remain for a long time unrecognized.

Pkctex nevadanus Conrad.

1856. Pecteri nevacUinus Conrad, Pac. R. R. Rept., vol. 5, p. 329, 8, fig. 77.

1888. Pecten iieradnuus Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., for 1887, p. 258 (in part).

1898. Pectin Conrad, Dall, Trans. Wagner Free Inst. Sri., vol. 3, pt. 4, 1898, 7CX).

Oriijhud description and not*:, — ''Ovate, flat or slightly concave; ribs 17, large, flattened on the interstices strongly wrinkled transversely.

"This shell is so nearly allied to N, (should be P,) \phrvynu of Maryland that, taken in connection with catillifonn!s it may be regarded as a Miocene species. The strata in which they occur may safely be referred to that period.

'' Ijtcality. — Ocoya Creek [Kern County].''

This species, like the last, was, according to Dall, described hy Conrad from one of Professor Blake's drawings of an external mold. The figure and description in the Pacific Railroad Report appears to fit hotrers! quite closely. The size of the sh<'ll, lumber and shape of ribs, and the characteristically sculptured byssal area are similar in the two but the writer has hesitated to place the latter in the synonymy of /'. nrradanus owing to the uncertainty of using so few characteristics in a definite specific determination of such importance,

Pecten PYxiDATi's Carpenter.

1863. P*'-/// ;>//.r/V//f/f/s Carpenter, Hrit. Assn. 1863, p. 667.

1898. PerteripyrlflntuM Dall, Trans. Wagner Free Inst. Sci., vol. 3, 4, 1898, p. 711.

This species is listed ])y Caqx'nter as having been collected by Captain Stone at Guaymas, Gulf of California. According to Doctor Dall this is probably a Chinese species.

142 Tertiaky And Quaternary Pkctens Of California.

Pecten 8UBCRENATUS Carpenter.

1863. Pedn Carpenter, Brit. Asan. Kept., 1863, p. 667.

1898. Perten C&rpentiiT, Dall, Trann. Wagner Fret Innt. Sci., vol. 3, pt. 4, 1898, p. 711.

This species is cited by Carpenter as being a possible synod-m for the P. pyxldatm above referred to. It is characterized as a list name by Doctor Dall, and is now unidentifiable.

Peoten townsendi (xoiild.

1863. Pecten To j/Twirf/ Gould, Carjienter, Brit. Aawn. Kept., 186:, p. 532.

1898. Pecten Townsendi Gould, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 711.

This species is said by Carpenter to come from Puget Sound. It is also a list name, was never characterized, and is, consequent-, now unidentifiable.

bibliography. Agassiz, Louis.

1856. Notice of the fossil fishes: Pac. R. R. Rept., vol. 5, appendix, pp. 318- 316, pi. 1. Washington. AxTON, H. E.

1839. Verzeichniss der Conchylien. Pectinea, pp. 18-20. Halle. Arnold, Delos and Ralph.

1902. The marine Pliocene and Pleistocene stratigraphy of the coast of southern

California: Jour. Geol., vol. 10, No. 2, pp. 117-138, pis. 1-5, figs. 1-7. Chicago. Arnold, Ralph.

1903. The paleontolog}' and stratigraphy of the marine Pliocene and Pleistocene

of San Pedro, Cal.: Mem. Cal. Acad. Sci., vol. 3, pp. 420, pis. 37. San Francisco, June, 1903. Arnold, Ralph, Haehl, H. L., and.

1904. The diabase of the Santa Cruz Mountains in San Mateo County, Cal.:

Proc. Am. Phil. Sck5., vol. 43, pp. 15-53, figs. 1-25. Philadelphia. Ashley, (j. H.

1895. The Neocene stratigraphy of the Santa Cruz Mountains, California: Proc. Cal. Acad. Sci., 2d ser., vol. 5, pp. 273-367, pis. 22-25. San Francisco. Blake, Wm. P.

1856. Notice of remarkable strata containing the remains of Infusoria and Polythalamia in the Tertiary formation of Monterey, Cal.: Proc. Acad. Nat. Sci. Phila., vol. 7, 1855, pp. 328-331. Brauns, David.

1881. Geology of the environs of Tokio: Mem. Sci. Dept., Univ. of Tokio, No. 4. Brckiger, AV. C.

1901. Om de senglaciale og postglaciale nivaforandringer i Kristianiafeltet (MoUuskfaunan): Norges Geologiske Undersogelse, No. 31, pp. 731, plates 19, text figures 69. Kristiania, 1901.

Bibliography. 143

Carpenter, P. P.

1857. Report of the present state of our knowledge with regard to the Mollu.sca

of the west coast of North America: Kept. Brit. Asso. Adv. Sci. for

185t). pp. 159-8(>8, 4 })ls. London. 1864. Supplementary report on the present state of our knowledge with regard

to the mollusks of the coast of North Americii: Kept. Brit. Asso.

Adv. Sci. for 1803, pp. London, 1864.

Clark, W. B.

1891. Correlation papers. Eocene: Bull. 17. S. Geol. Sui'vey, No. 88. Washington. Conrad, T. A.

1850. Descriptions of the fossil shells: Pac. R. R. Kept., vol. 5, appendix, pp. 317-330, pis. 2-9. Washington.

1857. Description of three new genera: twenty-three new species middle Tertiary fossils from California, and one from Texas: Proc. Acad. Nat. Sci. Phila., 1st ser., vol. 8, 1850. pp. 312-310. Philadelphia.

1857. Description of the Tertiai'v fossils collected on the surve}-: Pac. R. R. Rept., vol. 0, pt. 2, pp. 09-73. pis. 2-5. Washington.

1857. Report on the paleontology of the survey: Pac. R. R. Rept., vol. 7, pt. 2, pp. 189-190, pis. i-10. Washington.

1803. Descriptions of new genera, subgenera and species of Tertiary and Recent shells: Proc. Acad. Nat. Sci. Phila., 2d ser., vol. 0, 1802, pp. 284-291.

1807. Paleontologicai miscellanies: Am. Jour. Conch., vol. 3, 1807, pp. 5-7. Philadelphia. Cooper, J. (t.

188S. Catiilogue of Californian fossils: Seventh Ann. Rept. Cal. State Min., pp. 223-308. Sacramento.

1894. Catalogue of Californian fossils, parts 2, 3, 4, and 5: Bull. Cal. State Min. Bureau, No. 4. San Francisco. Datx, W. H.

1.S71. Diagnoses of sixty new forms of mollusks from the west coast of America and the north Pacific Ocean: Am. Jour. Conch., vol. 7, pp. 93-100, pis. 13-10. Philadelphia.

Fossil mollusks from later Tertiarics of California: Proc. U. S. Nat. Mus., vol. 1, pp. 10-10. Washington.

I88r). Report on the results of dnnlging hv the V. S. Coast Survey steamer 'Blake." XXIX. Report on the MoUusca, pt. 1. Brachiopoda and Pelecvpoda: Bull. Mus. Comj). Zool., vol. 12, No. 0, pp. 171-318, pis. 1-\K Mass., Septemher, lS8*i.

1889, 1903. A preliminary catalogue of the shell-hearing ma.ine mollusks and hrachiopods of the soutlKastern coast of the* United States, with illustrations of many of the speci(\s: Bull. V. S. Nat. Mus., No. 37, pp. 215, pis. 47. Washington, 1889. Reprint, pp. 232, pis. 95. Washington,

Bibliogkaphy. 145

KCSTER, C. H. , and Kobelt, W.

1888. Systematischos Conch31icn-Cabinet (Mai-tini imd Chemnitz) Die Gattungen

und Pecten, pp. 296, pis. 72. Bauer & Kaspe, Nurnberg,

Lawson, a. C.

1893. The Post-Pliocene diastrophism of the coant of southern California:

Bull. Dept. Geo!., Univ. Cal., vol. 1, No. 4, pp. 115-160, pis. 8-9. Berkele}'.

1894. The geomorphogeny of the coast of northern California: Bull. Dept.

Geol., I'niv. Cal., vol. 1, No. 8, pp. 241-272. Berkeley.

1895. Sketch of the geology of the San Francisco peninsula: Fifteenth Ann.

Kept. U. S. Geol. Survey, 1893-94, pp. 399-476, pis. 5-12. Washington. Merriam, J. C.

1896. Note on two Tertiary faunas from the rocks of the southern coast of

Vancouver Island: Bull. Dept. Geol., Univ. Cal., vol. 2, No. 3, pp. 101- 108. Berkeley.

1897. The geologic relations of the Martinez group of California at the typical

locality: Jour. Geol., vol. 5, No. 8, November-December, 1897, pp.

1898. The distribution of the Neocene sea urchins of middle California and its

bearing on the classification of the Neocene formations: Bull. Dept. Geol., Univ. Cal., vol. 2, No. 4, pp. 109-118. Berkeley. 1900. Lists of fossils in "Oil and Gas Yielding Formations of California," by W. L. Watts: Bull. Cal. State Min. Bureau, No. 19, pp. 218-224. Sacramento.

1904. A note on the fauna of the lower Miocene in California: Bull. Dept.

Geol., Univ. Cal., vol. 3, No. 16, pp. 377-381. Berkele}'. Newcombe, C. F.

1S93. Report on tlie marine sliells of British Columbia: Bull. Nat. Hist. Soc. British Columbia, art. 5, pp. 29-72. Richard Wolfenden, Victoria. OsMONT, Vance C.

1905. A geological section of the coa>;t ranges north of the bay of San

Francisco: Bull. Dept. Geo!., Univ. Cal., vol. 4, No. 3, pp. 39-87, pis. 6-7. 1905. Areas of the California Bull. Dept. Geol., Univ. Cal., vol. 4, No. 4, pp. 89-l0(), pis. S-11. Philippi, R. a.

145. Abbildungen und Beschreibungen neuer oder \V(*nig gekannter Conchylien, Bd. 1, Pecten, pp. 2Ul-2()4, taf. viii, 6. Cassel. Reeve, L. A.

1855. Conchologia iconic, vol. 8, Monograph of the genus Pecten, species 1-176, pis. 1-35. London. Rivers, J. J.

1904. Descriptions of some undescribed fossil shells of Pleistocene and Pliocene formations of the Santa Monica range: Bull. So. Cal. Acad. Sci., vol. 3, No. 5, May, 1904, pp. 69-72, tigs. 1-4. Los Angeles. 17260-No. 47-06 10

146 Tertiary And Quaternary Pe0Ten8 Of California.

Sowerby, G. B.

1835. Descriptions of new species of shells in the collection of Mr. Cuming:

Proc. Zool. Soc. Lond., 1835, pp. 109-112. London. 1843. Thesaurus Conchyliorum, vol. 1, Monograph of the genus Pecten, pp. 45-82, pis. 12-20. London. iSowERBY, James.

1829. The Mineral Conchology of Great Britain. (Continued by James D. C. Sowerby.) Vol. 6, + index to vols. 1-6, pp. 250. London. Stanton, T. W.

1896. The faunal relations of the Eocene and upper Cretaceous on the Pacific

Coast: Seventeenth Ann. Kept. U. S. Geol. Survey, pt. 1, pp. 1005- 1060, pis. 63-67. Washington. Taylor, George W.

1895. Preliminar}' catalogue of the marine Mollusca of the Pacific Coast of Canada, with notes on their distribution: Trans. Roy. Soc. Canada, 2d ser., vol. 1, sec. 4, pp. 17-100. Ottawa. Trask, J. B.

1855. Descriptions of Calif ornian fossil shells: Proc. Cal. Acad. Nat. Sci., vol. 1, pp. 40-42. San Francisco. Turner, H. W.

1898. Notes on some igneous, metamorphic, and sedimentary rocks of the Coast Ranges of California: eTour. Geol., vol. 6, pp. 483—199. Chicago. Vaughan, T. W.

1900. The Eocene and Oligocene coral faunas of the United States: Mon. U. S. Geol. Survey, vol. 39, pp. 263, pis. 24. Washington. Verrill, a. E.

1897. A study of the family Pectinidte, with a revision of the genera and

subgenera: Trans. Conn. Acad. Sci., vol. 10, pp. 41-96, pis. 16-21. Weaver, Charles E.

1905. Contribution to the paleontology of the Martinez group: Bull. Dept. Geoh, Univ. Cal., vol. 4, No. 5, pp. 101-123, pis. 12-13. Weeks, F. B.

1902. North American geologic formation names; bibliography, synonymy, and distribution: Bull. U. S. Geol. Survey, No. 191, pp. 448. Washington. Whiteaves, J. F.

1887. On some marine invertebrata dredged, etc., in British Columbian waters:

Trans. Roy. Soc. Canada, vol. 4, sec. 4, pp. 111-137. Montreal. 1893. Notes on some marine Invertebi-ata from the coast of British Columbia: Ottawa Nat., vol. 7 (being vol. 9 Trans. Ottawa Field Nat. Club), pp. 133-137, pi. 1. Ottawa. Whitney, J. D.

1869. Geological Surve}' of California, Paleontology, vol. 2, preface, pp. vii-xiv. Philadelphia. Williamson, Mrs. M. B.

1902. A monograph on Pecten sequisulcatna Carpenter: Bull. So. Cal. Acad. Sci., vol. 1, No. 5, May 1, 1902, pp. 51-64, pis. 4-6. Los Angeles.

Plates 11 To .

Plate Ii.

Eocene Pectens.

fUnleas otherwise stated all figures are approximately natural size.]

Page.

Fio. 1. Pecten ( Chlamys) calkirm n. sp. U. C. Cotype 61

Exterior of imperfect right valve; altitude 29 mm. Tejon formation (Eocene), Sisar

Valley, Ventura County, Cal. (S.)

Fig. 2. Pecten ( (lilamyn) calkirm n. sp. U. C. Type 61

Exterior of imperfect left valve; altitude 45 mm. iSame locality as fig. 1. (8.)

Fig. 3. Pecten ( Chlamys) landed n. sp. U. S. N. M. 164926. Type 51

Exterior of right valve; altitude 31 mm. Eocene, Little Falls, Lewis County, Wash.

(xM. P.)

Fig. 4. Pectm {Cfdamys) landesl n. sp. V, S. N. M. 164926. Cotype 61

Exterior of left valve; altitude 22.5 mm. Same locality as fig. 3. (M. P.)

Fig. 5. Pecten ( Chlamys) landesi n. sp. U. S. N. M. 164926. Cotype 51

Exterior of right valve (coarse-ribbed form); altitude 34 mm. Same locality as last.

(M.P.)

Fig. 6. Pecten {Chlamys) proavus n. sp. U. S. N. M. 164930. Type 52

Mold of interior of left valve, showing portion of external surface sculpture; altitude

38 mm. Eocene, between headwaters of San Lorenzo River and Pescadero Creek,

San Mateo County, Cal. (M. B.)

Fig. 7. Same specimen as fig. 6 52

Portion of disk showing sculpture; enlarged twice.

Fig. 8. Pecten ( Chlamys) proavus n. sp. I J. S. N. M. 164930. Cotype 52

Fragment, of a large specimen. Same loc4ility as fig. 6.

Fig. 9. Pecten ( Propeamtmum) interradiatvs Gabb. Type 53

Exterior of left valve; altitude 25 mm. Copied, with slight alteration, from Pal. Cal.,

vol. 2, pi. 33, fig. 98. Tejon formation (Eocene), New Idria, San Benito County,

Cal.

Fig. 10. Same specimen as fig. 9 53

Mold of interior of left valve; altitude 25 mm. Copied, with slight alteration, from

Pal. Cal., vol. 2, pi. 33, fig. 98.

Fig. 11. Pecten ( Jopeamushim) interradiatus Gabb 53

Outline of hinge line and ear of right valve. Copied, with sMght alteration, from

Pal. Cal., vol. 2, pi. 33, fig. 98a.

"The initials immediately following the name of the specimen are those of the institution or individual to which the specimen belongs, and to which reference is made in the introduction; the initials or letter at the conclusion of the explanation indicates the artist who retouched the figure.

U 5. Geological Survey

HOFESSIONAL PAPEft NO. 47 PL, II

PLATE III. olioocenp;-mi()Cenp: .

[TTnh8s otherwiw stated all ftfirvs are approximately natural .size.]

Pasra

Via. 1. Perteii n. np. IJ. S. N. M. 164928. Cotypo 57

Imperfect of exterior of rijjht valve; hinge line 0.5 mm., X 8. ( 4070, Bean Point, King County, Wash. (M. P.)

Fui. 2. Pt'ctet) (Propeamnfium) rlaHamenAM n. sp. IT. S. N. M. 1(>4922. Cotype 57

Imperfect mold of interior of left valve; altitude 7 nun., X 3. Ixk*. 4100, IJ miles east of Hilar Point, Clallam (\)unty, Wash. (M. B.)

Fio. .'5. Pevten Jopeamvsmm) cUillnmensisn. sp. U. S. N. M. 164922. Type 57

Mold of exterior of left valve; altitude 10 mm., X 3. Same locality as fig. 2. (M. P.)

Fk;. 8a. Same specimen as fig. 3 57

Portion of disk (not mold) enlarged 6 times.

Fkj. 4. Pevten (Propeaimmum) vniylandi n. sp. U. 8. N. M. 164924. Type 58

Imjjerfect mold of exterior of left valve; longitude 7 mm., X 3. Same locality (4100) as fig. 2. (M. B.)

Fkj. 5. Peden ( PropeamiLftmm) vxtylandi n. sp. IT. S. N. M. 164924. Cotype 58

Mold of interior of right valve; altitude 10 mm., X 3. Oligocene-Miocene, 4115, miles west of Gettysburg, Clallam County, Wash. (M. B. )

6. Perh-n ( Pseudannutium) jeckhami (iabb. Type 56

Exterior of left valve; altitude 21 mm. from Pal. Cal., vol. 2, pi. 16, fig. 19. SpiMimen from (Jjai ranch, Ventura County, Cal.

Fk;. 7. Pcvteu ( PxeudamuKium ) perkhami Gabb. Cotype 56

Outline of hinge line and ears of right valve. Copied from Pal. Cal., vol. 2, pi. 16, fig. 19a. Same locality as fig. 6.

Fiq. S. Pt'deu [Pstudamumim) peckhaml Gabb. (T. S. N. M. 164839 56

Casts of right and left valves in matrix. Monterey shale (Miocene), southeast of Pinole, Contra Costa County, Cal. (M. P. )

Fig. 9. Peclen ( ( lilamy) hnmneri n. sj). L. S. J . U. Plastotype 65

Cast from imjierfect mold (type) of left valve; hinge line 33 mm. Vaquero formation ( lower Miocene) , Tuff Hill, near Stanford University, Santa Clara County, Cal. (M. P. )

Fkj. 10. Pefieii ( Chlaniy) hranneri n. sp. L. S. J. U 55

Cast from fragment of mold of disk, showing 8cul})ture. Sanje locality as fig. 9. (M. P.)

Fio. 11 . Pecten ( Chtamys) hratmeri n. sp. L. S. J. T 55

Cast from fragment of mold of disk, showing Same Iwality as fig. 9. (M. P. )

Fk;. 12. Pecten ( Pecten) :i'cruzensis n. sp. L. J. F. H . CotypKJ 54

Kxterior of portion of right valve; longitude 48 mm. San formation (Oligocene), Bear Creek, Santa County, Cal. (M. B.)

Fk;. 13. Peden ( Perien) mnvUrcruzengU n. sp. L. S. J. U. PlastotyjHJ 54

Pxterior of cast from mold (tyiH?) of left valve; altitude 52 nmi. San fonnation (Oligocene), Twolyar Creek, Santa Cruz County, Cal. (M. B. )

U. S. Geolcxsical Survey

PROFESSIONAL PAPER NO. 47 PL. Ill

Oligocene-Miocene Pectens.

Plate Fy.

Miocene And Pliocene Pectens.

[Uuless otherwise stated all figures are approximately natural size.]

Page.

Fig. 1. Pecten (Peden) carrizoensis n. sp. D. A. Type 59

Exterior of right valve; altitude 36 ram. Carrizo formation (Miocene), Alverson Canyon, San Diego County, Cal. (M. B.) Fio. la. Same specimen as fig. 1 59

Exterior of left valve. Ih. Same sjxjcimen as fig. 1 59

Profile of both valves viewed from rear. (M. P.) Fig. 2. Pedm {Pecten) caiTlzoenm n. sp. U. S. N. M. 164847 59

Exterior of left valve; altitude 68 mm. Miocene, Santa Rosalia, Lower California. ( M. P. ) Ficj. 3. Pectai (Pecten) carrlzoemiii n. sp. U. S. N. M. 164848 59

Exterior of imperfect right valve; longitude 44 mm. Same locality as fig. 2. (M. B. ) 3. Same specimen as fig. 3 59

Profile of right valve viewed from front. ( M. P. ) 4. Pecten ( Pecten ) coalingaeims n. sp. L. S. J. U. Type 97

Exterior of slightly distorted right valve; altitude 47 mm. Pliocene, Coalinga, Fresno County, Cal. (M. B. ) Fig. Aa. Same specimen as fig. 4 97

Profile of right valve viewed from rear. (M. P.) Fig. 5. Pecten ( Pecten) amlingaeims n. sp. C. A. S. Cotype 97

Exterior of left valve; altitude 35 mm. Lower Pliocene, Kreyenhagen's ranch, Fresno County, Cal. (S.)

U. S. Qeolcxsical Survey

Professional Paper No. 47 Pl. Iv

Miocene And Pliocene Pectens.

Plat E V.

Miocenk Pectens.

[rnlew otherwiHc xUited all figures are approximately natural size.]

Fiu. 1. Pecten (Pecteii) keep ii. sp. D. A. Type 60

Exterior of Hoiuewhat imperfect and worn left valve; altitude 75 mm. Miocene, Carrizo Cre district, San Diego County, Cal. (M. P.)

Fig. 2. Pecten ( Pathwperten ) dilleri Dall. U. S. N. M. 104846. 62

Exterior of imperfei't right valve; altitude (restoreil) 180 mm. Upper Miocene or lower Plio<-ene, Eel River, County, Cal. (M. B.)

Fig. 3. Pecten ( Chlamijs) nesjiffmis var. hydei n. var. D. A. 69

exterior of right valve, anterior ear missing; altitude 46 mm. Vaqueros sandstone (lower Miocene), Lynch's Mountain, Monterey County, Cal. (M. B.)

Fig. 3</. Same specimen as tig. 3 69

Exterior of left valve, anterior ear missing. (M. B. )

Fig. 36. Same s|>ecimen as fig. 3 69

Profile of valves as viewed from the rear. (M. P.)

O

U. 8. Qeoloqical Survey

Professional Paper No. 47 Pl. V

Miocene Pectens.

Plate Yi.

Miocene Pectens.

[ITnlcflH otherwiHo HtattMl all tlgures are natural mIzc.]

Fig. 1. Pecteri {Pecten) keep n. sp. D. A. Type fiO

Exterior of right valve; altitude 7o mm. Carrizo formation (Miocene), Oarrizo Creek district, San Diego County, Cal. (M. P.)

Fi(}. la. Same specimen as fig. 1 60

Pr()file of right valve from rear. (M. P.)

Fig. 2. Pecten Pai'mopecten) cooseims Shumanl. U. S. N. M. 107791

of left valve; altitude 103 mm. Empire formation (Miocene), Coos Bav, Greg.

U. 8. QEOLOQtCAL SURVEY

Professional Paper No. 47 Pl. Vi

Miocene Pectens.

Plate Vii.

Miockne Pectens.

[Unless otherwise HtAted all rtgure.s are natunil size.]

Page.

Fig. 1. Pecten {Patinopecten) propatulus Conrad. U. C 64

Mold of interior of right valve, nhowinga [>ortion of the unilxinal area and ears; altitude 90 mm. Antoria formation (Miocene), Astoria, Oreir. (H.)

Fig. 2. Pecten ( Patinopecten ) roosetufls Shumard. U. S. N. M. 1077iU 61

Exterior of right valve, anterior ear slightly broken; altitude 103 mm. Empire formation (Miocene), Coos Bay, Greg. (M. P.)

Fig. 2{/. Same specimtjn as fig. 2 61

Profile of both valves, viewed from rear.

U. 8. Qeoloqical Survey

Professional Paper No. 47 Pl. Vii

Miocene Pecten8.

Plate Viti.

Miocene And Pliocene Pecten8.

[UnlesH otherwise stated all figures are approximately natural size.]

Page.

1. Pecten ( Patinopecten) oweni n. np. U. C. Type 63

Exterior of right valve, anterior ear slightly broken; altitude 85 mm. (LTpper Miocene?), Foxin*8 ranch, Santa Harbara County, Cal. (M. B.) Fk;. la. Same as fig. 1 63

Exterior of loft valve. (M. H. ) Fig. 1/>. Same as fig. 1 63

Profile of both valves from rear. (M. P.) Fig. 2. Pecten ( Chlamytt ) nespeeims n. sp. C. S. M. B 69

Portion of mold of interior of right valve; altitude 50 mm. Vaqueros formation (lower Miocene), Sespe Canyon, Ventura County, Cal. (M. B. ) Fig. Same specimen as fig. 2 69

Portion of mold of interior of left valve. Fkj. 3. Pecten [Chtamys) nespeenm n. sp. C. S. M. B. Plastotype 69

Cast of exterior of slightly left valve (young); altitude 18 mm. Same locality as fig. 2. (M. B.)

U. S. Geological Survey

Professional Paper No. 47 Pl. Viii

Miocene And Pliocene Pectens.

Plate Ix.

Miocene Pectens.

otherwise stilted all figures are approximately natural size.]

Fio. 1. Pecten Pallnopecten) propatulus Conrad, I'. 8. N. M. 3558. Cotype 64

Exterior of portion of right valve; altitude 100 mm. Astoria formation (Miocene), Astoria, Oreg. (M. B.) Fio. 1. Same specimen and valve as fig. 1 64

Portion of disk, showing part of two and included interspace, X 3. (M. B. ) Fio. 2. Same specimen as fig. 1 64

Exterior of portion of left valve. Fig. 2a. Same specimen as fig. 1 , left valve 64

Portion of disk, showing part of three ribs and included interspaces, X 3. (M. B.)

U. S. Qeoloqical Survey

PftOFESSfOML PAPER NO. 47 PL. IX

Miocene Pectens.

Plate X.

Miocene And Pliocene Pectens.

[ oiluTwiHf all figures are approximately natural size.]

Page.

Fig. 1 . Pectm ( Chlannjn) facanm Dall. U. S. N. M. 164933 66

Exterior of imperfect right valve; altitude 83 nun. Miocene, coast of Strait of Juan de Fiica, eat of Clallam Bay, Clallam County, Wash. (M. B. )

Fi. 2. Pecten ( Chlamys) fucanm Dali. V. S. N. M. 107790. Pla-stotyiK* 66

Cast of exterior of left valve; altitude 81 nun. 8ame locality Hk. 1.

Fio. Same specimen as lig. 2 66

Protile of left valve viewed from front. (M. P.)

Fici. 3. Pfvteu {('hiamijs) vattsi var. moran n. var. 1-. S. N. M. 104929. Type 121

Exterior of right valve; altitude 63 mm. Lower Pliocene, Moran's place. Priest Valley, Monterey County, ('al. (M. B. )

Vui. 4. Pertni {CfUamyn) vfiUxi var. inormii n. var. U. S. N. M. 16492). Cotype 121

Exterior of imperfect left valve; altitude 59 mm. Same locality as fig. 3.

Fi(}. 5. Pecten ( Chlamyfn) watts var. mornni n. var. U. S. N. M. 164929 121

Exterior of imperfect left valve; longitude 41 mm. Same locality as fig. 3.

Fro. 6. Pecten ( Chlami/s) vattHi var. moran n. var 121

Exterior of imperfect left valve (young); altitude 30 mm. Same locality as tig. 3.

U. S. Qeolcx3Ical Survey

Professional Paper No. 47 Pl. X

MIOCENE AND PLIOCENE PECTENa

Plate Xt.

Miocene Am) Pliocene Pectens.

[tlnU'ss otherwiw Htated all figures are approximately natiirul size.}

Paire.

Fig. 1. Pecten (Chin lit ys) irattai n. iip. C A. 8. : 120

Exterior of slijjlitly left valve; altitude 66 iiiiii. Lower Pliocene, Kreyenhagen's ranch, Fresno County, Cal. (8.)

Fig. la. Same specimen as fig. 1 120

Profile of left valve, viewed from rear. ( M. P. )

Fig. 2. Pecten ( Chlamijs) hamlini n. sp. IT. 8. N. M. 164844. Type 67

Exterior of cont<)rted right valve; altitude 50 mm. Miocene (lower?), he4id of Slacks Canyon, Monterey County, Cal. (M. B.)

Fig. 3. Pecteji {Chlamys) nufteri n. D. A. Tyjx' 67

Exterior of slightly imperfect right valve; altitude 74 mm. Purisima formation (lower Pliocene), south of mouth of San Gregorio Creek, San Mateo County, Cal. (M. B.)

Fig. 4. Pectm {ChtomiH) nutter i n. ep. C. S. M. B. 14125. Cotype 67

Exterior of slightly imperfect left valve; altitude 63 mm. Lower Pliocene, Kreyenhagen's ranch, Fresno County, Cal. (M. B. )

4a. Same as fig. 4 67

Profile of left valve, from rear. Fkj. 5. Pecten cracnrdo Conrad var. hamiltoni n. var. 8. N. M. 164845. Type. 73 Exterior of slightly contorted and im[)erfect right valve; altitude 40 mm. Miocene, Alum Rock Canyon, Santa Clara ( -ounty, Cal. 6. Pecten (Lyropedeu) cramcarfh Conrad var. hamiltoni n. var. U. S. N. M. 164845.

Cotype 73

Exterior of imperfect (earless) right valve; altitude 63 mm. Same locality as last.

U. S. Geological Survey

Professional Paper No. 47 Pl. Xi

Miocene And Pliocene Pectens.

U. S. Geological Survey

PROFESSIONAL PAPER NO. 47 PL. Xii

Miocene Pectens.

Plate Xiii.

Miockne Pectens.

[Unless otherwise stated all flgwres are imtural size.]

Pajre

Fio. 1. Pecten ( Lyroppclen) howerm n. sp. U. C. TyjHi 70

Exterior of left valve, ears altitude 150 nun. Mioeene (lower), Santa Inez Canyon, Santa Barbara County, Cal. (H.)

Fig. 1. Same specimen fijjj. 1 70

Profile of both valves viewed from rear. (M. P.)

U. S. Geological Survey

Professional Paper No. 47 Pl. Xiii

Miocene Pectens.

Plate Xiv.

Miocene Pectens.

[Unless otherwise stated all figures are approximately natural size.]

Page

Fic.. 1. JWfen ( Lyropecten) perrini n. sp. L. S. J. U. Type 80

Exterior of right valve; altitude 150 mm. Vaqueros sandstone (Miocene), Morro and Turo creeks, San Luis Obispo County, Cal. (M. B. )

\n. Same specimen as fig. 1 80

Profile of both valves viewed from rear. (M. P.)

U. S. Geological Survey

Professional Paper No. 47 Pl. Xiv

Miocene Pectens.

PLATE XV. miocp:ne pi:.

[Unless otherwise stated all figures are approxinialely natural size.]

Paife.

Fio. 1. PerteJi (Lyroptrten ) perrini n. sj). L. S. J. U. Type 80

Exterior of imperfect left valve; altitude 150 inin, VaqueroH sandstone (Miocene), between Morro and Toro creeks, San Luis Obispo County, Cal. (M. B. )

Fuj. 2. Pt'cten (Plagiodeiilum) imthensin n. sp. V. S. N. M. 5912. Type 87

Exterior of riglit valve; longitude 49 mm. Miocene, Strait of Fuca, east of Neah Bay. Clallam County, Wasb. (M. B.)

Fig. 2a. Same specimen as fig. 2 87

Exterior of im[>erfect left valve. (M. B. )

Fig. 2h. Same specimen as fig. 2 87

View of both valves from the rear. (M. B.)

U. 8. Geological Survey

Professional Paper No. 47 Pl. Xv

Miocene Pectens.

PLATE XVT. MIOCENE pp:ctp:ns.

fTTnless otherwise stated all fiKuren are approximately natural fdxe.]

Page.

Fkj. 1 . Pecten ( Lyrojcien) crasslcardo Conrad. U. S. N. M. 154154 71

Exterior of slightly right valve; 155 mm. San Pahlo formation (Miocene), Kirker Pawn, Contra Costa County, Cal. (M. B.)

\(i. Same specimen as tig. 1 71

Profile of right valve viewed from rear. (M. P.)

U. 8. Qeological Survey

Professional Paper No. 47 Pl. Xvi

Miocene Pectens.

Plate Xvii.

Miocene Ppxtens.

[UnlfSH otherwise stated all tlgureM are approximately natural size.]

Page.

Fig. 1. Pecten ( Lyropeden) cnmicordo Conrad. U. C 71

Exterior of slightly imperfect right valve; altitude 97 nun. San Pablo formation (upper

Miocene), Contra Costa County, Cal. (M. B. )

Fu;. \a. Same sjHximen as fig. 1 71

Exterior of iniperfe<*t left valve. (M. B.)

Fk;. 1/>. Same specimen as fig. 1 71

View of both valves from the rear, showing constriction of disk. (S.)

U. S. Qeoloqical Survey

Professional Paper No. 47 Pl. Xvii

Miocene Pectens.

Plate Xviii.

Miocene Pectens.

[Unless otherwise stated nil flguns are approximately natural size.]

Fig. 1. Pecieti ( Lt/ropecten) cnisnicardo Conrad. A. N. 8., Phila. TyjH* 71

Exterior of left valve (ears gone); altitude Ki mm. Miocene (probably upper, or iSan Pablo formation), ''California." (Photograph ])y Ralph Arnold. Shell not coated.)

Fkj. 2. Pecten ( Lyropectai) cmmcardo Conrad. C. S. M. B. 12772 71

Exterior of left valve (ears gone); altitude 88 mm. Miocene, Ventura County. (S.)

Fi({. 2a. Same specimen as fig. 2 71

View of both valves from the rear, showing constriction of disk. (M. B.)

P L A E Xix.

Miockne Pectkxs.

[UnlcHs otherwise all Jijiires are approxinialely natunil Hize.]

Fig. 1. Pecten ( Lyropeden) estreUmnis< Conrad. U. S. N. M. 74

Exterior of left valve; altitude 97 inin. Santa Margarita formation (upper Miocene), VVildhorse Canyon, Monterey County, Cal. (M. B.)

Fig. la. Same specimen as fig. 1 74

Interior of left valve. (M. B. )

U. 8. Geological Survey

PROFESSIONAL PAPER NO. 47 PL. XtX

Miocene Pectens.

PLATE XX. miocene: and pliocene pectens.

[Unless otherwise sUited all figures are approximately natural size.]

Page.

Fio. 1. Pecten ( Lijropecten) edrelUmns U. S. N. M. 13317. 74

Exterior of portion of imperfect right valve; altitude 90 mm. Santa Margarita formation (upper Miocene), Estrella valley, San Luis Obispo County, Cal. (M. B. )

Fig. 2. Pecien ( Lyropeiin) eslrclhtmis Conrad. C. S. M. B. 12871 74

Exterior of very convex right valve (form described as P. rohvft/rmis Conrad); altitude 71 mm. San Pablo formation (upper Miocene), Coalinga, Fresno County, Cal. ( M. B. )

Fig. 2a. Same sijecimen as fig. 2 74

Profile of right valve viewed from rear. (M. P.)

Fui. 3. Pecten estrellwius Conrad var. ccdaUniv n. var. D. A. Tyjn* 76

Exterior of imperfect right valve; altitude 68 mm. Upper Miocene, near Isthnms, Santa Catalina Island, Los Angeles County, Cal. (M. B. )

Fig. 3a. Same specimen as fig. 3 76

Profile of right valve viewed from the rear. (M. P.)

4. Pecten estrellanm Conrad var. catalhuc n. var. 1). A 76

Interior showing umbo and hinge; hinge line 30 mm. Same locality as fig. 3. (M. B.)

Plate Xxi.

MIOCKNE PKCrrENS.

[rules-* olhorwi.ve slated all figures are natural size,]

Pate,

Fi<;. 1. Pevten ( Liiropvrlen) eMreWtnuH Conrad. C. S. M. B 74

Exterior of right valve (ears imperfect); altitude 77 nun. San Pablo formation (up{)er Miocene), Coalinj, Fre.<no County, Cal. (M. B. )

FUf. ht. Same specimen an fig. 1 74

Exterior of left valve (M. B. )

\h. Same specimen a.s fijr. 1 74

View of valvea from the rear, showing constriction. (M. B. )

Fig. 2. IWten ( Lt/ropecteu ) mtrdhinuH J. 1 1. W 74

Exterior of right valve (ears slightly broken); altitude 00 mm. Miocene, Cholame Mountains, 40 miks east of Paso Robles, San Luis Obispo County, Cal. (M. B. )

Fi<;. 2a. Same specimen as (ig. 2 74

Exterior of left valve (ears slightly broken).

2h. Same s[>e'imen as fig. 2 74

of both valves viewed from rear.

Plate X X I T .

Miocene Pectens.

[Unlos otluTwisc stated uU tigures are approximately natural size.]

Page.

. 1 . Pectt'H ( Ltfroptctcn ) migtuiensln n. sj). U. C. Type 79

Exterior of somewhat right valve; ahitiide 110 mm. Miocene (lower), San Miguel Island, Santa Barbara County, Cal. (M. B.)

FiCt. la. Same specimen as lig. 1 79

Exterior of somewhat imperfect left valve. (M. B. )

Fi<;. 1 h. Same specimen as fig. 1 79

Somewhat distorted of both valves from rear. (M. P.)

U. S. Geological Survey

Professional Paper No. 47 Pl. Xxii

Miocene Pectens.

Plate Xxiti.

Miocene Pecten.S.

[Unless otherwise stated all figures are approximately natural size.]

Page.

Fig. 1. Peden (Ltfropecten) miguelaisis n. sp. U. S. N. M. 6397 79

Exterior of unibonal region imperfect ears of left valve; altitude of fragment 76 mm. Copied from drawing by Doctor McConnell. Miocene, Santa Inez Mountains, Santa Barbara County, Cal.

Fig. 2. Pecteu ( Li/rojtecten) estreUanns Conrad var. termmuH n. var. U. C. 77

Exterior of right valve; altitutle 70 mm. Santa Margarita formation (upper Miocene), Monterey County, Cal. (M. B.)

Fig. 2a. Same specimen as fig. 2 77

Profile of right valve, viewed from rear. (M. P.)

Fig. 3. IWJm ( Lyropeden) vnuyhnni n. sp. D. A. Type 81

Exterior of right valve; altitude 37 mm. Miocene (lower), Ojai Valley, Ventura County, Cal. (M. B.)

Fig. 3. Same specimen as fig. 3 81

Exterior of left valve. (M. B.)

Fig. 3/>. Same specimen as fig. 3 81

Profile of both valves, viewed from the rear, showing contraction of disk. (M. P.)

Fig. 4. Peden ( Propeamimum ) stanfonhnsiH n. sp. D. A. Type 91

Mold of interior of right valve and of exterior of left valve; altitude 7 mm., X 3. Miocene, Burke ranch, near Stanford University, Santa Clara County, Cal. (M. B.)

Fig. 5. Peden ( Pseudamnsium ) lompicoemis n. sp. U. S. N. M. 1G4931 89

Mold of exterior of left valve; altitude 14 mm., X 3. Miocene shale, head of Lompico Creek, Santa Cruz County, Cal. (M. P.)

U. S. Qeoloqical Survey

Professional Paper No. 47 Pl. Xxiii

Miocene Pectens.

PLATE XX rV.

Miocknk Pfxtkns.

[l"nUsH (ithcrwisc' statt'd all fiKurcH iirc a]>proximntely natural size.]

Pape.

Fi<;. 1 . IWtni ( Lyrttpecten ) mafjiiolin Conrad. C 77

Kxterior of rijrht valve (anterior ear inisHing), altitude 145 nun. VaqueroH formation (lower Miocene), Ojai ranch, Ventura County, Cal. (8.)

Fkj. 2. Pecien ( Lyroptrtni ) magiwlin ( 'onrad. Ij. S. J. V 77

Exterior of umbonal ngion and cars; hine line 95 mm. Miocene (lower), iKJtween Morro and Toro creeks, San Luis Obispo County, Cal.

Plate Xxv.

Miocene Pectens.

[Unless otherwise stated all fijfurejs are approximately natural size.]

Page.

Fig. 1. Pectm {Lyropecten) magnolia Conrad. U. S. N. M. 13325. Cotype 77

Exterior of vaive, showing characteristic Sculpture and shape of ribs; altitude of fragment 130 mm. Vaqueros formation (lower Miocene), Santa Inez mountains, Santa Barbara County, Cal. (M. B.) '

Fig. 2. Pecten (Plof/loctenium) cerrosensis (abb Var. mendenhalU n. var. U. S. N. M. 164849.

Type 84

Exterior of right valve; altitude 43 ram. Miocene, Santa Rosalia, Lower California. (M. B.)

2a. Same specimen a? fig. 2 84

Exterior of left valve. M. B. )

Fig. 26. Same specimen as fig. 2 84

Profile of both valves, viewed from the rear. (M. P.)

Fig. 3. Pecten ( PhKjiocUmum) eldridgei n. sp. U. S. N. M. 164850. Type 87

Exterior of left valve; altitude 20 nmi. San Pablo formation (upper Miocene), McKittrick district, Kern County, Cal. (M. P.)

Fig. 3. Same specimen as fig. 3 87

View of interior of left valve. (M. P.)

Fig. 36. Same specimen as fig. 3 87

Profile of left valve, viewed from rear, showing great convexity. (M. P.)

Fig. 4. Pecten (Plagloctemum) eldridgei n. sp. U. S. N. M. 164850. Cotype 87

Exterior of right valve (anterior ear slightly broken); altitude 17 mm. Same locality as fig. 3. (M. P.)

Fig. 4a. Same specimen as fig. 4 87

Profile of right valve as viewed from the rear. (M. P. )

Fig. 5. Pecten ( Plagioctenium) eldridgei n. sp. U. S. N. M. 164850. Cotype 87

Exterior of right valve (anterior ear broken); altitude 23 mm. Same locality as fig. 3. (M. P.)

Fig. 5o. Same sjcimen as fig. 5 87

Profile of right valve as viewed from the rear. ( M. P. )

6. Pecten {Plagioctenium) eldridgei n. sp. U. S. X. M. 1(>4850 87

Exterior of fragment of a large valve of this species. Same locality as fig. 3. (M. P.)

Plate Xxvi.

Miocene Pecten8.

[Unless otherwise Htated all flies are approximately natural size.]

Piige.

Fig. 1. Pecten ( Phgioctenium ) deaeril Conrad. D. A 85

Exterior of slightly worn right valve; altitude 85 mm. Miocene, Carrizo Creek district, San Diego County, Cal. (M. B.)

Fig. 2. Pecten ( Plnffiocteiiium ) deserti Conrad. D. A 85

Exterior of slightly imperfect right valve; altitude 40 mm. Same locality as for fig. 1. (S.)

Fig. 2a. Same specimen as fig. 2 85

Profile of a somewhat unusually convex right valve as from the rear. (M. P.)

Fi(}. 8. Pecten ( Plogiocteimim ) dserti Conrad. I). A 85

Exterior of a slightly imperfect left valve; altitude 34 mm. Same locality as for tig. 1. (S.)

Fig. 4. Pecten ( Plagioctenlnm) deserti Conrad. D. A 85

Exterior of left valve; altitude 37 mm. Same locality as for fig. 1. (M. B. )

Fig. 4a, Same specimen as fig. 4 85

Profile of left valve as viewed from the rear. {M. P.)

Fig. 5. Pecten ( Ptagiocteniuni) u. sp. U. S. N. M. 164932. Type 82

Mold of interior of left valve with portion of exterior showing sculpture; altitude 38 mm. Miocene, Zayante Creek, Santa Cruz County, Cal. (M. P.)

Fig. 5a. Same specimen as fig. 5 82

Profile of left valve as viewed from the rear. (M. P.)

Fig. 6. Pecten ( Plngioctenium ) andersoni n. sp. L. S. J. U. Cotype 82

Exterior of left valve; altitude 14 mm., X 2. Miocene, Frenchman's Tower, near Stanford University, Santa Clara County, Cal. (M. B.)

Fig. 7. Pecten Plagloctenium) andersoni n. sp. U. S. N. M. 164932. Cotype 82

of right valve (anterior ear broken); altitude 20 mm. Same locality as fig. 5. (M. P.)

Fig. 8. Pecten ( Plagioctenium) andersoni n. sp. L. S. J. U. Cotype 82

Mold of interior of imperfect right valve, showing shape and sculpture of anterior ear; altitude 30 mm. Vaqueros formation (lower Miocene), Searsville road, near Stanford University, Santa Clara County, Cal. (M. B.)

Fig. 8a. Same specimen as fig. 8 82

Profile of right valve as viewed from the rear. (M. P.)

Fig. 9. Pecien (Plagioctenium) andersoni var. harkeriamis n. sp. and var. C. A. S. Type 83

Imperfect mold of interior of right valve showing portion of exterior, with sculpture; altitude 41 mm. Lower Miocene, Barker's ranch, Kern County, Cal. (S.)

Plate Xxvii.

[Unless otherwise stated all ligures are approximately natural Hize.]

Page.

1 . Pecteii ( PUigiodniiuni ) <Iiscuf( Conrad. U . C 8<)

Exttrior of left valve (anterior ear slightly })roken); altitude 4G nun. Miocene Walnut Creek, Contra Costa County, Cal. (8.)

1 a. kSanie specimen as fig. 1 . . 86

Profile of left valve as viewed from the rear. ( M. P. )

Fici. 2. Peden ( Plagioctenium ) flinrns Conrad. U. S. N. M. \3S'So. Type 86

Copied from a drawing by Doctor McConnell of a slightly contorted cast of the exterior of a left valve; altitude 47 mm. Miocene, Ventura County, Cal.

Fig. 3. Perten ( Plagioctenium ) iliscus Conrad. L. S. J. U 8t>

Wax cast of exterior of right valve; altitude 30 nnn. Miocene, Santa Maria, Santa Barbara County, Cal. ( M. P. )

Fid. 4. Pecten ( Pingiocteuium ) diufcuif Conrad. D. A 86

Mold of exterior of imperfect right valve; hinge line 24 mm. Miocene, between Morro and Little Morro creeks, San Luis Obispo County, Cal. (M. B. )

Fkj. 5. Pecten ( Plagioctenium ) pabloensis Conrad. 1). A 88

Exterior of left valve; altitude 34 nun. San Pablo formation (upper Miocene), San Pablo Bay, Contra Costa County, Cal. (M. P.)

Ficj. 5rt. Same specimen as fig. 5 . 88

Profile of left valve as viewed from the rear. (M. P.)

Fi. 6. Pecten ( PlagUtcteniam ) paldoensin Conrad. I). A 88

Exterior of imperfect right valve; altitude 32 mm. Same locality as fig. 5. (M. P.)

Fig. 6a. Same specimen as fig. 6 88

Profile of right valve as viewed from the rear. (M. P.)

Fig. 7. Pecten ( Plagioctenium ) pabloenniH Conrad. D. A 88

Exterior of right valve of a young specimen, showing prominence of ribs near umbo; altitude 24 mm. Same locality as tig. 5. (M. P.)

Fui. 8. Pecten ( Ptieuda murium) lompicoensis n. sp. U. S. N. M. 16493L Type 89

Mold of exterior of right (type) and left valves and cast of exterior of right valve; altitude of mold of right valve, 1 1.5 nnn., X 3. Miocene shale, head of Lompico Creek, Santa Cruz County, Cal. (M. B.)

Plate Xxv Tit.

Miockne And Pliocenk Pectens.

[l.'nli'Ks otluTwisL* stated all figuren are natural sizo.]

Page.

1 . Peden {Amunium ) hnnpor.erma n. sp. C'. A. S. 92

Mold of interior of left valve* altitude 105 mm. Miocene, 4 miles iouth of Santa Barbara County, Cal. (M. B. )

2. Peden ( Aimmiam ) lompocensis n. sp. U. S. N. M. 164852. Cotype 92

Interior of a portion of a left valve; altitude 90 mm. Mioiene (lower), Ojai Valley, V'entura County, Cal. (M. B. )

Fig. 3. Pevten ( AmuHiam) hnnpocensh n. sp. C. A. 8. 92

Im})erfeet mold of interior of right valve; hinge line 42 mm. Same locality fig. 1. (M. B.)

Fio. 4. Pecten {Psendnmmium) pedroanus Trawk. V. S. N. M. 164840 90

Exterior of imperfect left valve; altitude 30 mm. Pliocene, Third street tunnel, Los Angeles, Cal. (M. B. )

Fi<;. 5. Peden ( Psendnmumim ) peffroanux Trask. T'. S. N. M. 164840 90

Exterior of right valve and voung left valve; altitude of former, 22 mm. Same locality as fig 4. (M. B.)

U. 8. Qeoloqical Survey

Professional Paper No. 47 Pl. Xxviii

Miocene And Pliocene Pectens.

Platk Xxix.

Miockxk, Pliockne, And Pkctens.

[IJiilesH otherwise sIhUkI all fires are approximately natural size.)

Page.

1. IWtcn {Il'nmiten) ifigmitvan (Jray. U. S. N. M. 18886 98

Exterior of the left valve of the typi* of Conrad's JfijmHes nuiHsn; altitude 110 mm. 8anta Margaritii formation (upper Miocene), Santa Marjj:arita, San LuisObisiK) County, Cal. (M. H.)

Fuj. 2. Pectm [ UinaiteH) f/ifjanteiix Jray. U. S. N. M. 74166 98

Exterior of right valve; 70 mm. Recent, San Diejjo, Cal. (M. B.)

Fu;. 2fi. Same specimen aa fig. 2 93

Exterior of left valve. (M. B.)

U. S Geological Survey

Professional Paper No. 47 Pl. Xxix

Miocene, Pliocene, And Quaternary Pectens.

P I : A T K X X X .

Pliocenk Pkctens.

fl'nk'Ks otherwise stated all H|;ur(*s ari' approxiinatclv natural size.]

Page.

Fui. 1 . Pecten ( IWtin ) nwrriami n. Hp. V. S. M. Type 99

KxtiTior of rij'hl valve; altitude 120 miii. PlicKene, Pirn Creek, Ventura

County, (al. (M. B. )

Fkj. la. Same specimen as fi. 1. Profile of both valves as viewed from the rear. (M. P.) 99

2. Pevten ( I*ertni ) merrintnl n. sp. C. S. M. H. Cotypo 99

Exterior of imixrfect left valve, altitude llOnnn. Same locality as fig. 1. (M. B. )

U. S. Geological Survey

Professional Paper No. 47 Pl. Xxx

Pliocene Pectens.

Plate Xxxi,

Plkkene Pkctkns.

[Unless otherwise all lijrure** are approximately natural size. The liht in these tw<) fijfun's eoraes from the

side. Photoiruphs by Kalph Arnold.]

Pase.

Fid. 1. Pt'cten iPecten) hcnuif dmrdil A. X. S., Phila., 95

Exterior of rijjht valve of (iahlVH Janira hell; altitude SO mm., X 5/4. Pliocene, Santa Barbara, (al.

la. Same Hpedmen as lig. 1 95

Exterior of left valve, X 5/4.

U. 8. Geological Survey

Professional Paper No. 47 Pl, Xxxi

Pliocene Pectens.

PLATE XXXir.

Pliocene Fectens.

[Unless otherwise stattMl hU flK'JrcH are approximately nntiiral wize.]

Fio. 1. Ped (Pecten) atenrmfii Dall. U. 8. N. M. 148008 100

Exterior of rijrht valve; altitude 87 mm. San Diego formation (Pliocene), Pacific Beach, San Diego County, Cal. (M. B. )

Fiu. Irt. Same specimen as fig. 1 100

Exterior of left valve. (M. B. )

U. S. Qeoloqical Survey

Professional Paper No. 47 Pl. Xxxii

Pliocene Pectens.

Plate Xxxtti.

Pliocknk And Plkistockxe Fkctens.

[I'nle-HS othtTwI.so stated nil Hguros are approximately iiatunil size.]

l*SLge.

Fig. 1. Pecten ( Pecten ) rogdcHi i\. sp. D. A. Type 100

Kxterior of imperfect riht valve; altitude (>8 inin. San Pedro forinat'on (Pleintoeene), San Petiro, Los Anjreles County, Cal. (M. P.)

Fio. Same npecinien as fig. 1 100

Profile of right valve as viewed from the rear. (M. V.)

Fio. 2. Peden ( Pcrtni ) anhnn/i n. pp. C S. M. H. Type 94

ExttTior of imperfect right valve; altitude 4(> mm. Pliocene, Puente Hills, Iajs Angeles County, Cal. (S.)

Fir,. 2a. Same specimen as fig. 2 ., 94

Profile of right valve as viewed from the rear. (M. P.)

Fid. 3. Peden (Peden) hemphilli Dall. U. S. N. M. 7943. Type 97

Exterior of right valve; altitude 57 mm. San Diego formation (Pliocene), Pacific Beach, San Diego County, Cal. (M. P.)

Fig. 3a. Same specimen as fig. 3 97

Exterior of left valve. (M. P.)

Fig. 'Sh. Same specimen as fig. 3 97

Profile of both valves as viewed from the rear. (M. P.)

Fig. 4. Prden ( Peden) lecontei n. sp. I). A . Type 98

Exterior of right valve; altitude 59 mm. Pliocene, Cerros Island, off lwer California. (M. B.)

Fig. 4a. Same specimen as fig. 4 9S

Exterior of left valve. (M. B. )

Fig. 46. Same specimen as fig. 4 98

Profile of both valves as viewed from the rear. (M. P.)

Plate Xx Xiv.

Pliocknk Am) Plkistocene Pkctkns.

[Unless stilted all rtpures an approximately natural size.]

Page.

Fio. 1. Pt'cten ( Pecleu ) rogdeni n. sp. C. A. S. Ctitype 100

Kxterior of slightly imperfect left valve; altitude 74 nun. Pleistocene, Ventura County, Cal. (S.) '

Fi. 2. PertfH ( Peclen ) (inhurt/i n. sp. C S. M. B. Cotyie 94

Exterior of left valve; altitude 86 nun. Pliocene, Puente Hills, Loe Angeles County, Cal. (S.)

Fio. 2n. Same specimen as fiK. 2 94

Profile of left valve as viewed from the rear. (M. P. )

Fui. 3. Pecten ( Pntinopeden) jmrisimnnms n. sp. D. A. Type 105

Exterior of somewhat imperfect left valve; altitude 123 mm. Purisima formation (lower Pliocene), north of the mouth of Pescadero Creek, San Mateo County, Cal. (M. B. )

Fkj. 4. Pecten ( Patimtpecten ) tnrneri n. sp. L. R. J. V. Cotype 106

Exterior of a portion of the disk of a left valve. Pliocene. Tomales Bay, Marin County, Cal.

P L A T K X X X V .

Pliockxk Pioctkns.

[rnlens othTwiw state<! all figures aro appnixiniaU'ly natural size.]

Page.

Fkj. 1. Perten ( Patinoperteii) purisunaeiisla n. sp. I). A. Type 105

Exterior of a slightly iiniwrfect right valve; altitude 128 iiiin. Piirisinia formation (lower Pliotrene), north of the mouth of PescAilero Creek, San Mateo County, Cal. (M. B.)

Fkj. \(i. Same Hpecimen am fig. 1 lOo

Profile of both valves as viewed from the rear. (M. V.)

Fkj. 2. VMen {Ptitinopectt'u) turneri u. L. S. J. l. Type

Exttrior of an imperfect right valve; altitude ()5 mm. Pliocene, Tomales Bay, Marin County, Cal. (M. B.)

Fkj. 8. Pi'ctm ( Patinopertni ) turneri n. .s]). 1.. S. J. V. Cotype lOti

Exterior of a portion of a right valve showing sculpture; altitude of fnigment 4S mm. (M. B.)

Plate Xxxvt.

Pliocene Pectens.

[UiiU'Mw otliorwi.se stattKl all iire approximately natuml size.]

Pftee.

Fid. 1. Pectm ( Pntinopecten) healeyi n. pp. U. S. N. M. 154162. Cotype 103

Exterior of left valve; altitude 141 mm. San Diejjo formation (Pliocene), Pacific Beach, San Diego County, ( 'ai. (M. R)

Irt. Same specimen as lig. 1 - 103

Profile of left valve, as vieweti from the rear. (M. P.)

U. S. Geological Survey

Professional Paper No. 47 Pl. Xxxvi

Pliocene Pectens.

Plate Xxxaii.

Pliockne Pfxtkns.

[Unless otherwise stated all tiKuri's are approximately natural size.]

Page.

Fio. 1. Perten ( Pntinoprcten ) heaiofi n. sp. U. S. N. M. 148012. Type 103

Kxterior of right valve; altitude 121 mm. San Diego formation (Plioeene), San Diego

County, Cal. (M. P.)

Fut. Ir/. Same .specimen as fig. 1 103

Prolile of right valve, as viewed from the rear. (M. P.)

Fig. 2. Perten ( Pat'nwperten ) healeiji n. Hp. D. A 103

Kxterior of a portion of right valve; hinge line oO mm. Purifiima formation (lower

Pliocene), near 8an Gregorio, San Mateo County, Cal. (M. H. )

U. 8. Qeolooical Survey

Professional Paper No. 47 Pl. Xxxvii

Pliocene Pectens.

p r. A T E X X X AM I r .

PLIOCKNK AND tTATKHXARY PECTKN8.

[I'lih's-M otherwiw stated all fipiin's art* approxiinntolv nntunil size.]

Page

Fkj. 1 . IWtni ( Patimtpi'rtt'n ) canrliin:< ( Joiild. I). A 101

Exterior of riht valve; 105 miii. IMiocene, Dfadinau Inland, lfi Angeles County, Cal. (M. B. )

Fui. \(t. Same Hpeciiiien iiH fi. 1 101

Exterior of left valve. ( M. P. )

Fkj. Ih. Same speeimen as tijr. 1 101

Profile of Imth valv(*s, as seen from the rear. (M. P.)

Plat E Xxxtx.

PLIOCENK AND QlJATKRXAKY PECTKNS.

[ITnU'ss otherwise stated till Hjfures are approximately natural size.]

Page.

Fi<;. 1. Peden {Paimoperten) canr'nnu< Gould. V. 8. N. M. 18883 101

Exterior of imperfect right valve of type of Conrad's Peden meekii; altitude 154 ram. Pliocene, San Raphael Hills; Santa Barbara County, Cal. (M. P.)

2. Peden [Patiiiopeden) raiirhitu< iioiM. A. N. S., Phila 101

Exterior of right valve of type of Conrad's Perten heermauni; altitude 62 mm., X J. Pliocene, Santa Barbara, Cal. Photograph Riilph Arnold. (M. B. )

Fid. 8. Peden (PlngiodenUun) paucicostatuA C'carpenter. IT. S. N. M. 15634/a Type 137

Exterior of right valve, anterior ear broken off; altitude 32 mm. liecent, (lulf of California. (M. B.)

Fkj. Same specimen as fig. 8 137

Profile of right valve viewed from the rear. (M. P.)

Fio. 4. Peden {Pldijiodenium) pauclcosUitnM Carpenter. U. S. N. M. 15634A. Cotype 137

Exterior of left valve; altitude 8o mm. Same locality as tig. 3. (M. P.)

Plate Xl.

PLIOCKNK PiaTKXy.

[Unless otherwiHC all figures are approximately natural .size. The light in these two figures cornea from the right-hand side. SiH'cimen not coated ly Williams process. Photographs by Ralph Aniold.]

Page.

Fig. 1 . Pecien ( Xodipecteu ) rmlrhii Gabb. U. C. Type 106

Exterior of right valve; altitude 130 nini., X IMiocene, Cerros Island, off California. (M. B.)

Fkj. 1. Same specimen fig. 1 106

Exterior of left valve. (M. P.)

U. 8. Qeoloqical Survey

Professional Paper No. 47 Pl. Xl

Pliocene Pectens.

Plate Xlt.

Pliocene And Quaternary Pectens.

[Unless otherwise stated all Azures iiro npproximatcl y natunil size.]

Page.

Flo. 1. Pecten ( (.miujA) pnrmehei Dall. U. S. N. M. 154479. 119

Copied from Doctor McConneH's drawing of left valve; altitude 45 mm., X 5/4. (Trans. WagmT Free Inst. Sei., vol. 3, pt. 5, pi. 37, fig. 14.) 8an Diego formation (Plicxene), Pacific Bejich, San Diego County, Cal.

Fig. la. Same Hpecimen as tig. 1 119

Copied from Doctor McConnell's <lrdwing showing detail of secondary sculpture highly magnitied. {Idem. pi. 37, fig. 14</).

Fkj. 2. Pecten ( Chlamijs) opuntia Dall. U. S. N. M. 107752. Type 118

Copied from Doctor McConnell's drawing of right valve; altitude 33 mm. (Trans. Wagner Free Inst. Sci., vol. 3, [)t. 4, pi. 29, fig. 6.) San Diego formation (Pliocene), Pacific San Diego County, Cal.

3. Pecteii ( ( 'hlami/s) hartichi n. sp. U. S. N. M. 164841 . Type 107

Exterior of portion of disk; altitude 55 mm. Pliocene, Crescent City, Del Norte (>>unty, Cal. (M. P.)

Fici. 4. Perteii ( ChlamifH) hastaius Sowerby. U. S. N. iM. 13350 108

Exterior of left valve of Conrad's of Peden aUiplicatvs; longitude 55 mm. Pliocene, San Raphael Hills, Santa Barbara County, Cal. (M. B.)

Fio. 5. Pecten ( ) parmeleei Dall. V. S. N. M. 164842 119

Exterior of slightly right valve; altitude 70 mm. Pliocene, Crescent City, Del Norte County, Cal. ( M. B. )

5a. Same as fig. 5 119

Profile of right valve, as viewed from the rear. (M. P. )

Fid. 6. Pecten ( Chlamys) bellilameUafnjt n. sp. D. A. Type 108

Exterior of right valve (anterior ear slightly broken); altitude 18 nun., X 3. San Diego formation (Pliocene), Pacific Beach, San Diego County, Cal. (M. B. )

. 6a. Same specimen and valve as fig. 6, natural size. ( M. P. ) 108

Fi(}. 7. Same as fig. 6 108

Exterior of left valve, X 3. (M. B. ) 7a. Same specimen and valve as tig. 7, natural size. ( M. P. ) 108

U. S. Geological Survey

Professional Paper No. 47 Pl. Xli

Pliocene And Quaternary Pectens.

p r. ATE X I. r r.

PUOCKNK AM) QrATKRNAKY PFXTKNS.

[Unlew otluTwist? MtHttd all llgun!< are approximately natiiml wize. The Ught in tluw figures comes from the right-

haul side. I'hotoKraphM Ralph Arnold.]

Fkj. 1 . IWten ( Chlannf)*) hagUUtis Soworby. F. L. B 108

Exterior of right valve; altitude 59 mm. Keceiit, Monterey liay, Monterey County, Cal. Ficj. Same siKJcimen iijj. 1 108

Exterior of left valve. Fkj. 2. Pcrfen ( (Mamifx) haMaUm Sower])y. F. L. B 108

Exterior of right valve; altitude 49 mm. Same locality as Hg. 1.

Fkj. Same t*iK?cimen iw fig. 2 108

Exterior of left valve. Fkj. Perten {lkujioctenitnu ) rircularin 1 A 125

Exterior of right valve; altitude 54 mm.; San Pedro formation (PleistxH-ene), San Pedro, AngeleH County, Cal. Fkj. 4. IWten ( Pbujiock'mum ) circnhirh Sowerby. 1). A 125

Exterior of left valve; altitude 49 mm. Same locality a. fig. 8. Fkj. 5. Pectea ( Plnyioctenium ) nrnilarix Sowerby, variety. 1). A 125

Exterior of right valve; altitude 53 mm. Same Ideality aH fig. 3. Fkj. 6. Pccteu (/Va<//oc/mm//0 Sowerby, equilateral variety. D. A 125

Exterior of left valve; altitude 50 mm. Same locality as fig. 8.

P T. A T E XT. I r.

Am) Quatkknary Pkctkns.

[Unlesa othorwiso all llKuri's arc approxiniatoly natural nize. The light in these ntnirt's ctinieH from the righthand side. Photographs by Ralph Arnold.]

Ficj. 1 . J*('rtm ( ChlaunjH) hiMatus Sowerby. F. L. H 108

FiXterior of right viilvis altitude 5tt inin. Recent, Monterey Bay, Monterey C.-ounty, Cal. Fid. \n. Same an iij?. 1 108

Exterior of left valve. FuJ. 2. Prcten ( lildtnifs) huMatus Sowerby. F. L. H 108

Kxterior of rijjht valve; altitude 49 niin. Same locality as fij;. 1.

Fkj. Same aa fig. 2 108

Kxttrior of left valve. Fkj. 3. JWten ( l*Uxijioctenium ) rirciilaruf Sowerby. 1 A 1 25

Exterior of right valvt, 54 mm.; San Pedro formation (PleistK-ene), San Pedro, Los Angeles County, Cal. Fi(}. 4. IWtcii ( Plagioctf.ninm) clrculariH Sowerby. I). A 125

Exterior of left valve; altitude 49 mm. Same locality as fig. Fk;. 5. Vevh'n ( Plagioclenium ) nrnUarin Sowerby, e<|bilateral variety. I). A 125

Exterior of right valve; altitude 53 mm. Same locality as fig. 3. 6. Perlni {Plagioctcninm ) virnUarU Sowerby, exjuilateral variety. D. A 125

Exterior of left valve; altitude 56 mm. Same locality as fig. 3.

P L A E X T. T T I .

Miocknk, Pliocenk, And Quatkrnary Imoctens.

[I'lilesH otherwiw all ligures are approximately natuml Hize.]

Page.

FI(. 1. Pecien ( CMamya) hitstntvjt Sowerby var. mwarrhtis Dall. L. S. J. U 112

Exterior of riht valve; altitude 56 nini. Recent, Piiget Sound, Washinjjrton. (M. P.) Fid. 1. Same specimen as fij;. 1 112

Exteriorof left valve. (M. P. ) Fig. Ih. Same siHicimen as fig. 1 112

Profile of both valves from the rear. (M. P. ) 2. Penti (Chlamyn) hmUatujt Soverhy var. /<n'/t/ Carpenter. U. S. N. M. 150220 Ill

Pxterior of right valve; altitude 56 mm. Recent, southeast Alaska (II. S. Fish Com. stations 2850-285 1 ) . ( S. ) 2a. Same specimen as fig. 2 Ill

Exterior of left valve. (S. ) Fio. 3. Pecten (ChUtmyn) Aa//tw Sowerby var. /<mW?/s (lould. V. S. N. M. 3881 110

Exteriorof right valve of typical fonn of this variety; altitude 72 mm. Recent, Puget Sound, Washington. (M. P.) Fid. 3<(. Same specimen as fig. 3 110

Exterior of left valve. (M. P. )

Plate Xlit.

Plickene And Qitaternary Pectens.

[ITnloHs othen'ise stated all (igiiros are approximately natuml size.]

Fkj. 1. Pecten (dUamys) jordcmi Arnold. U. S. N. M. 162522. Type 114

Exterior of right valve; altitude 45 mm. Pliocene, Deadman Island, near San Pedro, Los Angeles County, Cal. (Mem. Cal. Acad. Sci., vol. 3, pi. 12, tig. 6.) (M. P.)

Fkj. \a. Same specimen as fig. 1 114

Exterior of left valve. (Idem.y pi. 12, fig. 7.) (M. P.)

\h. Same specimen as tig. 1 114

Protile of both valves as viewed from the rear. (M. P.)

2. Pecten ( Chlamijs) hatatus Sowerby var. utraieguH I )all. D. A 113

Exterior of left valve; altitude 36 mm. Pleistocene, near bath house, Santa Barbara, Cal.

Fkj. 2fi. Same specimen as tig. 2 113

Profile of left valve as viewcnl from the rear. (M. P.)

Fkj. 3. Pecten ( Chlamys) histatus Sowerby var. ntrategus Dall. D. A 1 13

Exterior of small left valve; altitude 21 mm. Pleistocene, San formation. Deadman Island, near San Pedro, Los Angeles County, Cal. (M. B. )

Fkj. 4. Pecten ( Chlamys) htiMcUnA Sowerby var. Mrategus Dall. D. A 113

Exterior of right valve showing secondary sculpture; altitude 21 mm., X 3. Same locality tig. 3.

Fkj. 5. Pecten ( Pittgiocteinutn ) cerrosensis (iabb. U. S. N. M. 61 246 123

Copied from Doctor McConnell's drawing of the left valve of Dall's type of Pecten mhirniricosm; longitude 63 mm. (Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, pi. 29, tig. 8. ) Pliocene or Pleist<)cene, Ventura County, Cal.

Fkj. 6. Pecten ( Phigloctenium ) circidarh Sowerby. F. L. B 125

Exterior of right valve; altitude 45 mm. Recent, (.xulf of California. (M. B. ) (Phowithout coating by the Williams process. )

Fkj. 6a. Same specimen as tig. 6 125

Exterior of left valve. (M. B.) (No coating.)

Fio. 6/>. Same specimen as tig. 6 125

Protile of both valves as viewed from the rear, showing great convexity of the typical form of this species. (M. P.)

Fkj. 7. Pecten ( P/aghctenhun) circularis Sowerby. U. S. N. M. 61246 125

Copied from Doctor McConnell's drawing of the type (right valve) of Dall's Pecten compactim; longitude 26 mm., X 7/5. (Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, pi. 34, fig. 5. ) Pleistocene or Pliocene, Ventura County, Cal.

Fio. 8. Pecten ( Propeamimum ) rirersi n. sp. D. A. Type 126

Interior of right valve, showing short internal line; altitude 17 mm. Pliocene, Santa Monica Canyon, Los Angeles County, Cal. (S. )

Fkj. 9. Peden ( Propenmusium ) rirersi n. sp. D. A. Cotype 126

Exterior of imperfect left valve; longitude 15 mm. Same locality as tig. 8. (S.)

PLIOCKNK AND lilJATKKNAKY PECTKNS.

[irnU'ss othiTwiMc stated all liKurrs an' approximately natural size]

Paire.

1 . IWtrn ( ( ixinudicus M iiller. I). A 118

Exterior of rijrht valve; altitude H3 mm. Keeent, Hanks of Newfoumllainl. (]M. B. )

Fkj. \a. Same s|)iH'imeii a.s iia. 1 113

Kxt<-rior of left valve. ( M. B. )

Fkj. 2. JWtm (Chlannf.) irunhhnnin n. sp. I S. N. M. 164843. Type 1 19

Exterior of imperfeet left valve; altitude 108 mm. Pliocene, mouth of YachateH River, Lineoln County, Oreg. (M. B. )

Fig. 3. Pectcn ( ChUimiji* ) lawsoui n. sp. C. A. S. 117

Exterior of rijjht valve ( umbo and ears missing) ; Icmgitude rv5 mm. Plioeene, 4 miles south of (fuadalupe, Santa Barbara County, Cal. (S. )

FHi. 4. IWteti ( }/t<) n. sj). C. A. S. (type 117

Exterior of an imperfect left valve in whieh the region has partially with plaster; longitude 34 mm. Same locality as lig. 3. (M. B.)

Plate Xlyi.

Pliocene And Quaternary Pectens.

[Unless otherwise stated all flfirureb are approximately natural size.]

Page. Fig. 1. Peden \Pecten) excavaius Anton. L. S. J. U 134

Exterior of right valve; 65 mm. Recent, CtuH of California. (M. B.) Fir., la. Same specimen as fig. 1 134

Exterior of left valve; altitude 57 mm. (M. P.) Fig. Same siKJcimen as fig. I 134

Profile of both valvcv as viewed from the rear. (M. P.) Fig. 2. Pecb-n ( ( %lamy) latiauritus Conrad. I). A 115

Pxterior of right valve; altitude 25 mm. San formation (Pleistocene), San Pedro, Angeles County, Cal. (M. P.) Fig. 2a. Same as tig. 2 115

Profile of right valve as viewed from the rear, showing convexity of typical form. 3. Pecten ( ( lilamys) Infianritua Conraii. 1). A 115

Exterior of left valve; altitude 27 mm. Same locality as fig. 2. (M. B.) Fig. 3f!. Same specimen as lig. 3 115

Profile of left valve iis viewed from the rear. (M. P.) Fig. 4. Pecten {Chlamys) latinuritu Conrad var. iiumot'nneriH Conrad. I). A 131

Exter or of right valve; altitude 20 mm. San Pedro formation (Pleistocene), Los Cerritos, Los Angeles Cal. (M. P.) Fkj. 5. Pecten ( Chlamt/n) latiauritna Conrad var. moiiofimeris Conrad. D. A 131

Exterior of left valve; altitude 22 mm. Same locality as fig. 4. (M. P.) Fig. 5. Same as tigs. 4 and 5 131

Profile of both valves, as from the rear. Note the greater (onvexity of the left valve as compared with the greater convexity of the right valve in JWtn s. s. (M. P.) F'kj. 0. Pecten (Chlamij.H) tatiauritiis Conrad var. cerritensia n. var. 1). A. Type 129

Exterior of right valve; altitude 24 mm. San Pedro formation (Pleistocene), San Peiiro, Angeles County, Cal. (M. B. ) Fig. 7. Pecten ( Chkunys) latinurUns Conrad var. cerritenms n. var. D. A. Cotype 129

Exterior of left valve; altitude 21 mm. Same locality as lig. 6. (M. P.) Fig. 8. Pecten {('hkimyn) latlaurituH Conrrni var. fncicolun Dall. U. S. N. M. 96049 131

Exterior of right valve; altitude 30 mm. Recent, on kelp, off Cerros Island, California. (M. P.) Fig. 8r. Same specimen as fig. 8 131

Exterior of left valve. (M. P.) Fig. 9. Pecten {Chlainy)) latiauritris Conrad var. delosi n. var. D. A. Type 130

Exterior of right valve; altitude 12 mm., X 3. San Pedro formation (lower jMirtion), Pleistocene, Deadman Island, near San Pedro, Los Angeles County, Cal. (S. )

Fig. 9a. Same as fig. 9, natural size 130

Fig. 10. Pecten (Chlamya) UttiaurUus Conrad var. delom. n. var. D. A. Cotype 130

Exterior of left valve; altitude 11 mm., X 3. Same locality as fig. 9. (S. ) 10a. Same specimen as fig. 10, natural size 130

U. a. QEOLOQIOAL SURVEY

PROFESSIONAL PAPER Na 47 PL. XLVl

r

Pliocene And Quaternary Pecten8.

Plate Xlait.

PLIOCKXi:

fl'nU'ss othtTwist' stati'<l all liRiires an' approximately natiiml sizo.]

Fit J. I. IWirn (hfrofH'cIni) iifihlrni i\. V. C. Typ(

Kxtorinr of rij;ht valve; altitude l.V> mm.

IMioceno, (Vrro.s Island, off Lower C-alifornia. (II.) Fk;. If/. Same sp'cim(*n W. 1

Outline of both valves as viewed from the rear. ( M. P. )

U. 8. Geological Survey

Professional Paper No. 47 Pl. Xlvii

Pliocene Pectens.

P L A T E X L V I 1 T .

Pliocene And Recent I'Ectens.

[rnk'ss otherwise Ktate*! all fi'irfH are approximately natural size.]

Page.

1 . Pecteii ( Lyropacten ) (tahU'tji n. sp. V. C. Typo 122

Exterior of left valve; altitmie 155 iniii. Pliocene, Cerros Island, off Lower (.'alifornia. (IL)

Fir,. 2. JWkn ( IWmfammhim ) rawhl/thi Dall. U. S. N. M. 107749 138

Exterior of riht valve; altitude 29 riini. Rwent, off Destruction Island, Wash., 516 fathoms. (T. S. Fish Com. station :VA4'S.) (M. P.)

Fio. 2a. Same as fig. 2 138

Exterior of left valve. ( M. P. ) Fkj. 3. Pect£it randolph Dall var. i'dhimookem'iH w. var. U. S. N. M. 150233.

Type 139

FiXtirinr of right valve; altitude 30 mm. Recent, off Tillamook, Oreg., 786 fathoms. ( r. S. Fish station 3346. ) ( M. P. )

3. Same as fig. 3 139

Exterior of left valve; altitude 31 mm. (M. R.)

U. 8. Geological Survey

Professional Paper No. 47 Pl. Xlviii

Pliocene And Recent Pectens.

Plate Xl Ix.

Pliocexk Pectkns.

[Unless otherwiwi KUitiMl all Hgiirt's are natural siz*?.]

Page.

1. PerUni ( PUnjiodniium ) rerroneiiHis i lahh. U. C- 123

Exterior of rijrht valve (anterior ear somewhat iniperfeet); altitude 1()6 mm. Pliocene, Cerros Islaud, off Lower California. (S. )

Fkj. 1//. Same PjHjeimen as fig. 1 123

Exterior of left valve (anterior ear slightly broken). (S. )

Fkj. 16. Same specimen aa fig. 1 123

Profile of valves an from the rear.

2. Pectni ( PlaguHteuium ) cooperi n. sp. D. A . Type 124

Ext<*rior of right valve (anterior ear somewhat imperfect); altitude ;i5 mm. San Diego formation (Pliocene), Pjuitic Beach, San Diego County, Cal. (M. B.)

Fig. 3. Pedm ( Plagiodeiihun ) rooperi n. sp. D. A. Cotype 124

Exterior of right valve; altitude 30 mm. Same locality as fig. 2. (M. B.)

Fio. 4. Pecten ( Plafjioctenium ) cooper i n. sj). 1). A. Type 124

Exterior of left valve; altitude 27 mm. Same locality as tig. 2. (M. B.)

U. S. Qeoloqical Survey

Professional Paper No. 47 Pl. Xlix

Pliocene Pectens.

Plate L.

Quaternary Pectens.

[Unless otherwise stated all figures are afiproximately natural size.]

Hage. Fig. 1. Pecten {Plagiodeiiium) riraUarh Sowerby var. irquisulcatim Carpenter. Ih S. N.

1 72703 132

Exterior of right valve; altitude 82 mm. Recent, San Pedro, Angeles County, Cal. (Photographed without coating to show coloration.) (M. B. )

la. Same Hpecimen as fig. I 132

Exterior of left valve. (Photographed without coating.) (M. B.)

Fig. Ih. Same as fig. 1 132

Profile of both valves as viewed from the rear. (M. P.)

Fig. 2. Pecini ( .Kfjulperten) jmlmeri Dall. U. S. X. M. Cotyjx 136

Exterior of right valve (voung); altitude 26 mm. Recent, head of Gulf of California. (M. P.)

Fig. 2a. Same specimen as fig. 2 136

Profile of right valve, as viewed from the rear. (M. P.)

Fig. 3. Pecten (.Kquipecten ) pabntrl Dall. U. S. N. M. 150980. Tyyte 136

Exterior of left valve; altitude 48 mm. Same locaHty as fig. 2. (M. P.)

Fig. 3a. Same specimen as fig. 3 136

Profile of left valve as viewed from the rear. (M. P.)

Fig. 4. Pecten {PHeudamus'nim) da ridsoui U. S. N. M. 107747. Type 138

Copied from Doctor McConnell's drawing of the right valve of the type; altitude 14.7 mm. (Proc. U. S. Nat. Mus., vol. 24, 40, fig. 6.) Recent, Davidson Banks, north of Unalaska, 351 fathoms (U. S. Fish Com. Station 3330).

Fig. 4a. Same specimen as fig. 4 138

from drawing of left valve. {Ideniy pi. 40, fig. 5.)

PL-vTE LT.

Quaternary Pecten8.

[Unless othtTwiMt' Hlutitl all t'lKiin's n' approximately natural size.]

Page.

Fkj. 1. Perten ( Perfeu) (lUwjemdH Dall. U. 8. N. M. 1501*80. Type 127

Exterior of right valw; altitude Hi\ mm. Recent, San Pedro, Angeles Cal., <lredged. (M. P.)

Fro. la. Same fig. 1 1 27

Exterior of left valve. (M. P.)

Fuj. 1 h. Same Hjeeimen in* fig. 1 127

Profile of valvehi as viewed from tlie rear. (M. P.)

Plate Lii.

[Unless oihmvise stati'd all liguros are approxiinatrlv natural size.]

Paife.

1. Peclen ( Xodiperh-n) auhiwdosus Sowerby. L. S. J. V 128

Exterior of right valve; altitude 112 iiini. liecent, wi'st coast of Mexico. (M. B. ) Fkj. 2. rwten {Chtdinffn) hatntm Sowerby var. itUndm Hall, V. S. N. M. 150207. Tyjie 136

Exterior of rijjht valve, Hhowiiig broad fasciculi; altitude 45 mm. Recent, Iliukliuk Harbor, Unalaska, ()8 fathoms (U. S. Fish Com. station 8818). (M. P.) Fkj. Same specimen as fig. 2 186

Extenor of left valve, showing narrow fasciculi. (M. P.) Vm. 8. Pi'cteu ( PaeudarnKsium) vnnrourercnsis Whiteaves. Tyix* 140

Copied from original drawing of right valve of type; altitude H mm., X 4. (Ottawa Naturalist, vol. 7, pi. 1, figs. 1 and b/.)

Recent, off Vancouver Island, British Columbia. Fkj. '.l. Same specimen as lig. 8 140

Copied from drawing of left valve of

U. 8. Geological Survey

PROFESSIONAL PAPER NO. 47 PL. Lll

Wm

Quaternary Pectens.

PLATE LI I r.

Quaternary Pkctkns.

[UnloKs othtTwisc stated all ligurcH aro approximiiti'ly natural size.J

Fi. 1. Peden ( Xodip4rfen) ttuhnodostiH Sowerhy. L. S. J. U 128

Kxterior of left valve; altitude 112 mm. Recent, wet coast of Mexico. (M. B. )

Fig. 1 a. Same siwcimeri an tij;. 1 128

Profile of valves as viewed from the rear. (M. P.)

Fkj. 2. JWten ( Propeumumun ) alaHkensis Dall. U. 8. N. M. 149()04

Exterior of right valve; altitude 22 mm. Recent, sonthwest of Pribilof Islands, Bering Sea, 80 fathoms. (U. 8. Fish ('om. station 3602.) (S.)

Fid. 2n. Same specimen as fig. 2 133

Exterior of left valve; altitude 25 mm. (Note diffenmce in size of right and left valves of same individual.) (8.)

Fkj. 3. Pecten ( Propeamimium) Dall. U. S. N. M. ()2343 133

Interior of slightly imperfect left valve, showing internal riblets; altitude 20 mm. Recent, Point Etches, Alaska. (S.)

U. S. Geological Survey

Professional Paper No. 47 Pl.

Quaternary Pectens.

Index.

rase.

Bittlum longiffiimnm 14

quadrifllatum Carpenter

rugatum Carpenter 34

williamson Arnold 34

Blake, W. P., on Monterey shale 20

Boreotrophon cerritennis Arnold 36

gracllia Perr>- 31,36

EsehtH'holtz 36,'l03

pedroaniiM Arnold 36

trlangulatiis Carpenter 37

Bomia retifera Dall :W

Bornonia bartuchl :<6

dalli Arnold 36

hoover Arnold 36

Boulder , Cnl.. rocks ntar 16

Brachiopoda 12. 17. 19, 27, 2K. so

Braehysphlngus llrutnH (iabb.* 12, 14

siniiatus Gabb 14

British Columbia, pecteuH of 109, 1 14

Buwinumsp 27,91,116,120.123

Bulla homi Gabb 14

punctulata A. Adams 34, 95

quoyl Gray 34

Bui lia striata Gabb 14

Bullinula Hubglobosa Weaver 12

Caduluu f usifonnis Sharp and PllHbry

Coeum callfomicum Dall

crebrlcinotum C-carpenter

magnum Stoarnn

California, formations in

fossil localities in 11, 13. 16. 18. 20-22. 26, 29, 32

fossils from 51 , 60-2, 64, 67-133, 139, 141

map of, showing fossil loealities 7

post-Crt'taceouH correlation table of 9-10

post -Cretaceous geologic column in 9

figure showing 9

Calliostoma annulatum Martyn 3.*)

canaliculatum Martyn 31, 36

cotitatum Martyn 36, 9r>

gemmulatum ('carpenter 36, 1 17

tricolor Gabb 31,35

8p 19,24,27,118,120

Callista angustlfnms Conrad 17.21.27

sp 17. 52,55,

Callistat4i subdiaphana CaqHnter 33, lOC

Calyptrophorus sp . Cancellarla ctwperi Gabb.

crawfordiana Dall

irelaniana Cooper

vetusta Gabb

Sp 84,95

Km

Cancer sp

Cardita sulxjuadnita Carpenter.

sp.

Curditamera Mibquadrata ( -HriKMiter

Caniium breweri Gabb 14, 17

cooper! Gabb 12, 14

<'orbi Martyn :}0, 33, 95.

eltitum Sowerby

linteum Connid

meekianum Gabb 24, 27

procerum Sowerby

Paips.

Cardlum quadrigenarlum Conrad 22, 23, 24, 30. 33, 96. 121

Hp 17.l9,5f2,79

C-arrizo Creek beds, equivalents of lu

fsunaof 21-22

Curyophyllia amoldi Vaughan 33

(alifornica Vaughan 30

pedroensLM Vaughan 33

Cassis sp 52

Catalina Miwene, equivalents of 10

Cephalopoda 17

Cerithidea califomiea Hahlemann 31, 35

CerithioiHis alternata Gabb 12, 14

Cerostoma monoceros Sowerby So

Chama exogyra Conrad 33

pellucida Sowerby 30, 33

(.hlco formation, equivalents of 10

occurrence of 9

Chicoreua leeanus Dall 36

Chlone tluctlfraga Sowerby 34

gnidia BnMk-rip and Sowerby , 27, 84, H4

mathewsonii Gabb 19, 21, 55, 67, 79

ncglecta .Sowerby 34

slmllllma Sowerby 31, 34

succincta Valenciennes 19, 30, Si, 104

sp 19, 24. 27, 65, 64, 66-67. 70, 73, 76. 79, 83, 85, W,

Chlamys Bolton 41. 46 -47, 4, 55, 66, 81, 94

bartschi 26, 37. 49, 107-108, 3W

bellilaniellatus 26, 28, 29, 37, 49, 108, SSe

branneri 16. 19. 37, 49, 66. 6fr-66, 88,

calkinsi 14,87,49,61,62,15

discus 95

fucanusDall 19,21.28,88,49,66-67, J6i

bamllni 19,38,49,67,122,165

hastatus .derby 29,

31 , 83-34, 38. 49, 69, 94, 108-110, 1 12, 1 15, 1 17. 229

var. albidus Dall 38. 49, 136, f8

var. hericius Gould 23-24,

26-29, 31, 33-34, 38, 49, 70, 109, 110-111, 112, 116, iSO

var. hindsii Carpenter 26,

29. 81, 33, 38, 49. 1 11-112, 116. 23r>

var. navarchus Dall 26,

28-29, 33, 38, 49, 112-1 Is, 115, 118. 2S0

var. Btrategus Dall 26. 29, 33-34, 38, 49, 1 18. SSg

htricfus no

var. Ai'nd/ Carpenter m

var. naixirchus Dall 112

var. strategus Dall 113

hf ricius var. albidus Dall 136

hydei Arnold , 69

islandicus MUller 16,

26. 29, 33, 38, 49, 52, 55, 107, 112, 118-11 4, 115, 120, 254

Jordan! Arnold 26.29,31,34,88,49, 114-116,f52

landesi 14. 38, 49, 51-651, 14

latlaurilus Conrad 26-27, 29-30, 33-34,

38, 47. 49, 82, 91 , 108, 1 1 5- 1 16, 123, 129, 131, 137, iSS

var. (rerrltensis 33-,34, 38, 49, 120-180, gSft

var.delosi 83-34, 38, 49, 180, i5

var. fnujilis Arnold 129

var. f ucicolUH Dall 33, 38. 49, 130, 181, £98

var. nioiiotimeris 3:4-34, 38, 49, 82, 181, SS6

lawson 27. 3S, 49, 117-118, 54

nutteri 19,21,23,27,39,49,67-68,l06,l8

opuntia Dall 27-29.39,49,91. 107, 116, 118, 123, tf

panneleei Dal 1 . . . 27, '29, 39. 49, 68, 100, 108. 1 19, 120-121, 226

prfa vus 11-12, 39, 62, 62-68, 14

sispeenKis 19, 39, 49, 69, ICO

var. hydel 19,39,49.60-70,79,83,154

washbumei .? 27, 39, 49.1 10-120, fa4

Vage.

Chlamys watlsi J7.:W.49.;7-6.M.',n9. 1:i0-121, 1J2. /v;

var. mumni..' 'J7,;W,49. lil-l*ii. /';',

bmnnoum :U, :r

fuiK'hnilf A. Arliim-

var. .suhajHTtnin Cariifiilcr

Kal Una Forbi'?!. '.Vt

montort'yi K ientT :n , :r

piiUlKo Martyii :i''

vlriluliim vir. liKiilamiii NU-nkr :i.'>

HI. 19.i!l

Chulanu* Valley Ihm1>. rcjiiivaU'nts <if 10

Chorus In'lrhfri Hiiul.s 'SA, 24. :i.'). TJl. 1 11

liratiis Murtyii '27.:so

recti nwtris :si , :i.')

tabulatus Bai nl -'7. W, M .

Hp 27. . lu:i

Clathurella (Mmnullana <;abb 81, :C>

Cilenientia CarpcnitT

Clidiophoru punctata Conrad 27. :W

Clypeawter liovverMi Merriani 22

breweriauus 17

Kabbi Remond 2;i

CoccluodlM'U.s sp A)

Codakia ti-'>

californian (iaskoin

chryHalloidea Carientcr 3r>

KausaiMta Gould 31 .

var. carinata Hinds :il . :Vi

mining Arnold 3.')

Arnold 35

ri<-hthoftfni (Jabb 117

solidula var. Arnold 35

tuberoNi Canx-'ntor ;i5

Colombia, pwttMjs of 126

Contra Costa MicM-cnc. MjuivKkMits oi 10

<K*curren('<' of 17

(!onu.s ralifoniic'us Hinds 31.35

hornirjiibb 11

rcniondi (Jabb 15

sp ll. 52, H4, 101

CoopiT, .1, <J., on fitxsjls 14

subdiapliana ('arpcntcr :;3

Cahjh conKlointTatc. .'(iuivalents of Hi

Coralliophila nux IUm'Vo 35

Corbula alii'forniis (iabb 11

ovansiana Shuniard VJ

horni <Jahb M

Inlcula Carpenter .no, :;3

14

Cordij-ra Knu'illitna Cooper 15

iniiToptyifTiui <iabb 15

('<rrL'latioii. post-CrelartM.uv, tjilU' showiiiu 10

Cras-atellilo'- lu'randi- U

niijoidcs Siantoii 12

nvawiiia ( 'oiirad 11

Cra'sineila braiiiiiTi Ann'M :i">

aciib-nta fimeliii ;j.'>

udinu'H Sowerby 21, :'.5

navic.'flloidfs Niirtall 27. .'W

prs:nii'ta Conrad 17

(rc|>idnla prinocps Connid 19.24.27.'2S,;W.A5,79,105,117

nijjosa Nuttall 27, 35, 9?)

, rtt;. 95

sp 84

Cru5tu'ea 12,19,24,28

Cryptorhiton stolleri Miiblendori 31,35

j-alifonilca Conrad 27,30, 33. tV5

CucuUaa matlu'wsoni Gabb 12

Cinna biplirata Gabb 19,79

( 'uminjii" <"alifjrnic'a 30, 33

Cylichna albai Brown 35

co-itata (Jabb 12

borni <;abb 17

pet n tsa ( tnrad 17, 21

Cypnea bayenjuei Gabb 15

niatbewsoiii (iabb 15

spadieeii (iray 35

-I' Jtt

(oibb 28

thara Itranneri Arnold 35

Cylherea Conrad 17,55

si 17,21,56,67

Dall. W. H.,on ejassitieation if jicctons 45-50

on .'an Pedro formation :J2

on Tertiary bori/ons 10

Deadman Island PlitK"one.ejuivHlcnts of 10

fauna of 30-31

DiMitalinm eooperi (iabb 12,15.17,52

indianorum CarjuMiter 35

UfohcxaKonum Sharp and IMlsbry 28, 95

nrohexaKoninn Sowcrby 35

pseudohexagonnm 35

BnMlerip and .Sowerby 35

st ra mineum ( Jabb 12, 15

MUbstriatnm Connid 17,57-58

sp 17, 19, m, 73, 84, 9:}, 95. 117

Drntiptcttn rirru/nriif Sowerby 125

sp 35

Diller, .1. S.. on ()li:ocene of Wa.shington 15

DiMlus tenuis Gabb 15

Pipbxlontu orlM' (Jould 33

serricata Keeve 21, 33

27.:W,117

tryoidana Gabb ;U>, 117

sp H4

Doliuin petroMUii 57-58

rinK<"" Sow erby 22

ealiiorniea Connid 33

l:evii,'ata Desbayes ;<3

ele\ ata iabb 14

Kyrata iiabb 14

mat iabb 19, 79, 83

montana Conrad 19,79

Gray 19. 23, 27, 7:J, 79,83, 104

hp 22, 27, 83-84

Drillia eancellata Caria-nter 35

hem|)hill Stearns 35

incina Carpenter 27, 30

bowers Vaughan

ealifondcus Weaver... earpenteriana Jabb.

eooperi

Index.

Pafft)

Drillialnermis Hindu 30,35

var. ponicillata CariKMiter 1

joIiiiMini Arnold 8ft

mcrriaini Arnold 31,35

toroiia (;arpntor 31. 35. 117

iillreyana 15

sp 95

K.

KchinantchniiiM cxueniricus EschM'hoItz. . . . 'JM.:{(i,33,99,122

up 10:1,117

Ec'hinoIdcH 1 ..',19. i-J, 23-'24, 27, 2, 30.

EnHpira al vcata Connid 15

Eocon rockH. forniationN of 9-15

faunaof I1-12.H-15

Dcrnrronrr of 9, 10

IKHJtensof 11. 14,37-41,51-54. if

Epona matlu'wwmi 15

Erato cohimlH'lla Monke 36

sp 57-5M

Eiilima falcnta ( 35

haHtata Sowerby :15

niicanH (.'ariK-Mitor 35

Eupleura niuriclfonnlH Hnnlerip 'A5

inuri<'lfcrinU var. curt Arnold 35

F.

Fairlmnkh. II. W.. on VaqiUTON sandnt4ine IS

FaM'iolaria io <fahh 15

ItnvluHoiila (Jabb 15

slniiaUi (iabli 15

Fauna, lines of 12, 14-15. 17, 19. 21-21. 2tl-31. :i:J-37

localities where found, lists of. . . 11 . 13. ir.. 20-22. 2t), 29. :i2

Favia nuTriaiiii Vaughan 22

horni Gabb 15

FisKuroUa volcano Reevi* 3r>

iniL'qualis Sowerby 35

nnirina (('ariH.'ntT) Dall :V),95

sp 19

FlalK'llum rallfomifuin Vaughan 14

renionilianuni (Jabb 12. 14

Foraminifeni 12

nunimuloid 12

Hp 12

Fort Tfjon. Cal.. nx'ks 13

Fossil looallt ios. lists of 1 1 . 13, 16. IM. 20-22. 26,

nmp showing location of 7

Fusiis iiquilatcralis Weaver 12

arnoldi :i6

iNirttarensis Tnisk 31 , :i'>. 95. 121

mliforni('u< Conrad 15

(Jabb 15

luti'opictUH Dall 35

martini/ (Jabb 15

matbow'srmii (Jabb 17

rircKonensis ('oral 17

rribustus Trak 24. :<5

nigitsus Trask 27. :i5

nupmplanus Cooper 15

Fusus thra<>ius Conrad. "I

17, 19, 24, 52. 57-69, 73, 93

(i.

Uadinia retienlata 35

Galenis exrentriciis Gabb 12. 15, 17. 19. 79

inoniatus (rabb 27

mammillaris Broderip 17, 19. 35

Gari alata Gabb 23

Gaaten 12. 1 4-1 5, 17, 19, 21-22, 24. 27-28, 30. 31 , H4-:i7

(lastrofhaena m] 22

Glottidiaalbida Hinds 27

Conrad :W

cor Gabb 14

patulus ('onrad 24. M. 118

Bagittata Gabb 14

Middendorf ;W

veatehii Gabb var. major Stanton 14

sp 19,21,23. 52. 6S. 73, 79, 3, 85. IIM

GlyphiM denslelathrata 91. 116, 123

Gyndes dowelU White 15

sp 73

H.

Haliotis fulgens Thilippi :<5

Hamintiii virescens Sowcrby 35

Hamlin, Homer, on Vaquenw sandstone 18

HeU'Ion diehotoma Gabb 12. 5:i

Helix f Kpiphragmophora ) sp 3.'

gabbi Stanton 12

striata Stanton 12

tnK'heidi'ta Gabb 12

sp 12

Hinnites iK-franco 41.4.SO,94

eortezi Defrance 50

rruiwi Conrad 93, W. MI

giganteus G ray 19.

21 . 22. 2:j. 26. 29, dii. 3h, 50, 9S-14, 95. 109. jW

jMulinnii Connid 98

HipiMjny X antiquatus Linnt 31, 31

Hyatt. A., on law of evolution 127

diegoensis Gabb 1-1

Isapis fenestrata Carpenter

iHchncMrhiton regularis Carpenter

I vara tnrrieula Dall and Bartsch.

:t5

:i5

Janim Mln Conraii 95-yii

iUvtaia iitihh ]00

f/oi/Mi Sowerby 136-I8i>

finridn Himis 12

K.

30,33

Kellia laperousil Deshayes

Montague 33

Kennerlia biearinata Carpenter 33. 108

Iacuna ompacta CariK*nter . Cariwuter

Indkx.

Pago.

Lacuna ( lvon) ('Hrpi'iitT H5

Iii'vicardiuni liiiteiim Conrad 14

MubhtriHtiim ('<inniil 27, IW

sp.

li

Lmncllaria tcarnsii 1 )nl 1

Lamna olavata Agassi/.

Iaqiii'iis <*aliforini'Us 77

jrffrtiysi DtiU -Jk, 30, 77

Lawtwm, A.(.'.,<>n MuiitiTfy >lial- 'JO.'Jii.'.M)

Ix-da alffiiformiH Galih 12

Uwsa 27. 33. M

gabbi <'oiirail 12.11

liamata Carprnicr :i3

niinuia var. Ariiohl ;>3

Jjttoittctrn timid'ttiiiK i/V ( >iirail i:'.l

Leptothyni hariilu 'M>

carprnttTi I'ilsbry

pauei('(>.Mata 1 27.

IMU'twyrlnx jiodroaiia ArimM

hanilini yi . 1 1.. 123

niultiraillata ( Jahl. 12, 1 1

I.irvpirtfn rratwcanfn Coimnl 71

riftrrltanu* t'onrad 74-7.'

Iltxrmanni Dall 7'). 101

rtatrhii ('(Mipor 77.

LithofthaRa plumiila Haiih-y 33

2l.:)0.3

:4.73

".). 32

1:.

Litorina planaxin Phil

romondi (Jabb J

scutulata (Jould

Littlo Fall-s Wa**li.. fiHTiiatioiis lu'ur

liOcalitifs. li.sts of ,. 11. 13. li. 1h.2(-22.2i.J

turrita (iubb

Lucafiina cn-uulata Sovvcrby

Lucapinrllu calloniarKinala ( 'arpvuti-r :;.')

Ln<*ina aculiliiH'ata 31. 117

-alifnrni-a (.'iinrad 31

(Tftarra <iabb U

tt'inuM-ulpta ('ariM'iit'r 31

LujMHiiji baynnn-i <;abb 1.")

Lniiatia (Jabb 12. 1')

b-wiii (ioiiM 2J.27.:;o,:t*;. 117-1 is

iiuciforini'* <Jabb 15

.sbiiiiianliaiia (Jabb l.'. 17

sp.

Lutniria traskii ('Miirad 20,21

Lyoii-'ia alifnrnia (\inrari 31, :i:;

Lyropict.ii 11. Wi, I1>. 71 . si . 1 n

asblcyi 2r.,

var. biimilliii 1*J.2;'., :'.s. T.t, 7:{-74.

<liabliM'ii.-i- \r:i..l.l 72

var <jitaliii:i- 23, 2"..3s. I'.J.r.:;. 7t>-77, /s',

var. trniiiiiMs 23, 2l.:t*, I'.t, 77. lif)

Jlftrni'inni I >al I 7'., 101 . 102

miKU'bMi-i 19, 39, 49, 7i)-S0. 10*2. I.ss, lno

lH.Trini 19, 21, 39, 49, 0-!Sl , /?.',

Lyroieoti'n vauKhani 19,39,49,Hl-K2,l.<

mlaUtnuh (.'onnid 74, 7.'>, IHU

>r.

Macoiria falcarta (Jiiu-lni 19, 27. 3t), 31, 33, 103

iiniintaJa ;i3

iiHUiinata l>("*luigi'.>i 27, :W, 31, 33. 103

na-suia 'onrad 17. 19. 2:1. 27. 30. 33, IW

var. kilstyi Dall...: 33

.iabulosa 30

secta Conrad 33, 99

y(>lilitormi< Carpf nitT 88

xp 17. 91 . 1 16-117, 123

Macron kfllettii Alani.>' 36

lividuK ZS

Martra <'alifonu'a Coiinid 19. 23, 24, 27, 33, 83, 103

ratillifornii.s 28, 67

r.xob'taiiray 34

fal(!a ta ( JouM 28, 24

b..'mjhilli Dall 27,84

Itlanulala H4

Mak*a Sowcrby 22,86

Mangilia anuulata ('ari'ntt'r 36

boovcri .\riioM 36

intorfosia var. la-diana ArnoM 36

interlirata .trains 36

oldniydi .Vriiobl 36

painei 36

wituralis CoMpcr 16

M-nlpttirata Dall 31.36

Map of 'alifornia. fossil hwalitifs .7

Marria sulxlia|)liana Carpenter 31

Margarita var. knei-hti .Arnold 36

ojttabilis var. nodou- 36

parcipicta var. peilroana 3G

Margaritella crt-nulata <;abb 16

Marginalia jowcltii Caritrntcr 36

Sf 67-68

.Marte.Ma 117

Martinf/,Cal., rncki near 11

Martiiu'/ formation. cliarartrr of n

fauna of 11-12

oi'Mirr.-nct* of 9,11

pecten.s of 11, :7-40

Mi'galrbi- bima iilatusDall 19,:

sp 12

Mrgistostoma striata ;abb 12. 16

Mi-. I.ako.rorks mar 28

fipiivalonts IQ

orciirniu*' of 9,2*-29

pc'tfiis(,f in*. 37-40

Mi'ictrix i'alifriiii-a Con rati ]4

li< trni . iabb U, :>l

ovalix ;abl> 14

uva.vaim <'ourad 14

sp 12.62

Mi'rriam. .1. C., on Contra Costa MiM'oni' 17

on Martin<*/. formation 11

on pi'<-tMi in ('rt'taci'ous shah; 64

on San Pabb.i formation 22,23

on Train formation 14

on Vaqurnis formation 18

Index.

Page. I

Merriam, J. C, <in Ventura County fonrilR 99 j

MetlH alta ronrart 2S, 34 ,

Moxico, fossils from m-61, 126, 129, 136-137, 139

Miocene iwks, formations of 10, 17-24

fauna of 18-19,21-24

(K'currence of 9. 17

pectens of ... . lS-19, 21 . 23. 37-42. Tit;, ft9-W. 11 1 , iSO

Mitra cretacea Gabb 15

maura S wainmn 36

filowi Carpt'iittr 36

internuHila Arnold 36

Modiolus fornicatiM farponter 34

merriami Weaver 12

omatus Gabb 12, 14, 51

rectuA Conrad 17, 27, 2m, 30, 34. 95

flp 17,23,69

Mocrella salmonca Can'nter 27, 34

MolopophoruH striata Gabb 14 i

Moniii macnw.hisma Dihayej* 34

MonocoroH engonatum (mrad 30, 36 I

lapilloidos Conrnd 36

MonU'rey, V.a\., rorks near 20

Monterey phule, eharacter of 20

equivalents of 10 I

faunaof 21-22

iK'ourrence of 9, 20-21 .

pectens of 21. 37-40 !

36

12,15

Naticina obliqua Gabb 15

NautilUH sp .Vj

Nesera pcctinata CarpH? 17, 34

Neptunca cntaceaGabb.

gracilis Gabb

Gabb

mucronata Gabb

pupraplicata Gabb . . .

sp.

Nerita trlangulata Gabb.

Nevcrita fjlobosa Gabb. . .

reeluziana Petit

saxea Cmrad . secta Gabb

lo

22.28,31,36,79,91,95,104,116.121,123

Mopalia cilinta Sowrrby.

Morio tuberculatus Gabb

Mulinia densiita (iabb

Murcx fpstivus Hinds

foliatus Mii-rtyn

leeiinus

monfxjoros Sowerby

nuttalli Conrad

trialatus Soworby

sp

Myrtea?

Mysia polita (iabb

Mytiliuieria nuttalli Connul

MytilUN asoin Gabb

californianuN Conrad

dichotomous Cooper

humerus Conrad

mathewsonii Gabb 19. 27, 70, 73,

sp 23,24,(

MytiluR e<]uivalents of

:% 5J 31.:V4

:{0

30-;ii

79, h6

N.

Nayi antiquata Gabb 15

califominua Conrad 27, 31, 86

cerrltensis Arnold 36

orctacea Gabb 15

fOHHata Gould 30-31,36.95,104

inseulpta Carpenter 36

mendiea <iould 19.27,30,31,36.100

perpinguis Hinds 27, 31. 36, 84. 95, 117

tegnla Reve 36

versicolor var. A mold 36

sp 2 J. 73, 91. 93, 99. 116, 12:J

Natica claaJa and Sowerby 27. 30, 31 , .36. lOJi

(H'oyana 'onriid 19. S3

lowisii Gould 'MS

reeluziana 95

uvasana <iubb 15

sp 120

Mp 24,120

nodosuH Linn 49, 129

subnodosuH . . . :)3-34, 89, 49, 107, 13H.1S9. th8, SSO

veatrhli Gabb 27. 89. 49, 98, 106-107, *'i

Norrisia norrisii Sowerby 36

Nucula castrensis Hinds 27, 81, 4, 65

decisa Connwl 67.66

supnistriata Carpenter 'M

truncata (? abb 12, 14

sp 17,55,67.58

Nutter, K. H.. work of 6s

O.

Oeinebni Imrbarensis Gabb

eaneelllna Philippi

foveolata Hinds

interfo.sa Carj'Uter

keep A mold

lurida Midd 19.

var. aspera Baird .

var. cancelling Philippi

var. cerritensis Arnold

var. munda Carpenter

micheli Ford

perita Hinds

poulsoni Nuttall

24,86

24,36

Hp 23,62

Odostomia gouldii Carpenter 36

nueiformis var. a vcllana 36

tenuis Carpenter 36

Oligoeene rocks, fauna of 16-17

fonnations of 9-10, 15-17

occurrence of 9,15

IHMtens of 16, 37-41 , M-59. l.V}

Oligocene-Miocene . pectens of 55, 57,

Oliva sp 22

Olivella Sowerby 80-31, 36

intorta Carpenter 28, 30, 31.

mathewsoni Gabb 15

pedroana Cmrad 19,24. 31, 3i;

Oliverato cnlifornica 14

Omphalius viridulum vnr. ligulatum Mcnke

Opalia anoniala Steams 28. 100

borealis Gould 36

condom Dall 120

<Tehitoides var, lns<>ulpta 3#

nintliewsoni Gabb 15

varicostata Stearns 28. 100

sp.

Oregon, fommtions in .

foRsil in ..

fossils from

Ostrea appressai (Jabb..

17,21

62.65,111-112,120.142

Indkx.

Page.

OHtri-a nttwfxxii Gabb 21

demiit Solander 1 i:i

Idrlariisis Gabb 12. U. 17, r.3

Inlanilici Miiller IIM

Islandiriii* MiilliT : llli

Inrlila ('-nter ;iJ. 122

maxima Liiino

palmnla Conrad 7(;. Ill

titan Coiira.l ly. 2U. 21. l. 70, 78. 70. 79. W

veaU'hii (ialib 2S. Ul. i*s. 107. IK), 123

ve.Miertina mrad 22. rl

Paehypoma iua-qimlc Martyii

"P

PulUum rraj/nticanlv (?onrad

tircltatmin ('onnul

Paludestriim eiirta Arnold

Mtokt'si Arnold

Pandora scapha Gabb

Pauomya ampla 27. ;il .

ParacyathiiH jiedroon.si.H VauKhan

Pasadena MicK'fne. eiuivak'nts of

Robles formation. of

Patvlla trnnki

Bp.

ry. 117

lu

Dull 11. 4H-4tt, Ca)

raiirinus <;ould 2(;.

SlMiniard 2:i, 37. 4", fll-2. lOo, i.6'. ;.'.s

dill.Ti Dull ;.v,

owing 23-24, 27. 3y. 19. f:MJI. t'-'S. 121 . Pio

propatulii" i'onnid iy.2l.23,;;9,49,J4-.'), i:>s, ir,:

piirisiniarii-iM 27, 39. 49. r.2. 105. .'/ ',

turiKTi 27. 39. 49. 1 Wl. m

Pectrii Mulli r 41-14, .'U-Iir.. ifs-jrui

,7f////V////v////j*Cnr|)rnttT 132

:i7..-o. 127. l:W-l:i4. l:ts.j:."

I p/<( iifinmiD'imK Altisknifiif 133

(j//i>/.v //>/A \Vhit.-aVf> i:i:i. 1 lo

Conrad Ins

oltii,fii'<itiis{\,nTiu\ lo'.). jy.

( l'lnL'iM"ii-niunri

21.2:;. ;;7. 17. '-i. 79. s2-s:{, sy.

var. ljarkTiaim- l' ly,;;7..Hi, s:{-s4. I'.:

( LyrojHMH-n i 2*').

iClilaiiiy>. iMrt-rlii 2r.. :;7. 49. 107-lOS. ;v;

(<'lilaiiiy>. iM.'llilaiM.-lIam- 2r..2s.2i.:'.7. ly. 10H,j,v;

lio\\rr-i.. 19.2l.:'.7. 17. iy. 70-71.111. ;,'()

H.:'.7. ly. :1.:)2. /',v

catilliloniiis iiiratl M. Ill

ran rin I >ii 1 1 W. 101.1 10

2y.::i.:!:'.-:;i.37.4s. ly. r..".. m*. loi-lo:t. kh;. ;.'.'

Paire.

Peotfn ( Pbigioctcnium ) ccrroeenfiiii Gabb 26, 229,

37, eA, 77, H4. 9H-99, 107. 12S-124, 125, 138, Wf , ?W var. mciidenhulli 19.

21 , 22, 23. 37. fio, 00, G3, H4-H6, K5. /94

rinnahariua Born 113

I PlajfifX-teninni ) clrculariK Sf>\very 33,

var. iHqiiiwulcatns CariH'iiter 33-A4,

37, .tO, sh, .s9, 124, 126. 1S2-1S8. iUU

I olallam*nsis 14,

1. 37, 50, 53. 57-68, 59, 150

ooalinpaen.si.'* 26. 37,48, 97,

rinninictus 1 125. 2flf

(Plaio'tenliHn) coopvri 2.2S-29.37,

( Patinopfcten 1 coosensin .Shnmard 23,

37.49.61-2.105.7f,/5

(HinnitcM citriozi Dofram-t' ,tO

1 LyrofK' 1 <ra.-ricardo 'onnid 1M,21, 38,

ly. 71-7. 7s. M. S3. S9, ir2-93. 122, 141, 176, 17S, ISO

var. hamiltoni 19,2:i.3,49. 7S-74,81, IM

IN.-ndaninsinm) davidsoni Dall 50, 134, 188, 2iW

ti'iitdttif A rn( lid 100

(Iriit'itun 134-136

( 1 'itla ttf ntafnH (wt-rby 135

(IMaKMortfiiinnn desert i <;onnid 19,22, 38, 50, 86,

Li/ropt rtt n 1 dinhltM Hi'fi' Arnold 72

difjfcnsi.s Dall 3:i, 3k, 48. W. 96, 98. 100, 1S7-128, :?46-

fPatinoiKMtin) dilliTl Dall 23, 2ti. 88. 49, 62, 105,1',

dislocatus .<ay l;W

I PlaKdocKninmi disrus Conrad 21.

23, 24, :JH. ."iO. 71. 73. 80. 82, 86-87, /iW

( Cfifiuiii/f) <lijtriin Conrad 86

dittrutt '(Kper 82, 86

( 1 iddrldgei 23. 21. 38, 50, 87, 191,

* thin Asliley 122

1 Lyrop*<ten est rellanus Conrad. . . 19. 21 . 23, 24, 38, 49, 64, ;7. 70. 72-74, 74-76, 77, 79-K, 102. 11 1, 1 H. lJ!, iSh, ISti

var. ralalinii- 23.2;,:iH.49.G3. 76-77. iSi

var. ti'rniinnv 2:.24,38,49, 77, i'W

xeavatn.s Anton :<8, 47, 48, t;i.".K>. 100,101, 184-186,'.%'

f PsiMnlamnMinn) rxoti<'US Cbemnitz 50

{Ptitnioptitni) expannus Dall 103-104

Falirini Philipii 114

(Propeamusinni 1 ii'nt'- Forbrs (A)

( I'o/c;, rtnri'lus Hinds 127

(Chlaniys) fnianns Dall 1 9. 21, 23, 3. 49, 66-67, /64

i Ilinniti''i ,'iKi''''i.- <;ray 19,

21 , 22. 2:5, 29, 'Xi. :{x, rH, 08-04, 95, 109. -Mil

handing 19,tW,4y.67.122,ififi

(Chlaniy*') lia'latn.> 2t)-29,

31 . :i3-:U. 3.H, 49, 09, 94. IOH-1 10, 1 12. 115. 117. 'JG, JH

var. albidu. Dall :J8, 49, 1 36. 2i.W

var. bericin- Gonld 23,24.26.

var. CarprnttT 26,

var. navanlni** Dall 20,

2'< 29, 3:i. :ix, 19. 112-1 13, 115, 118, 2,*;

var. .'U- Dall 2r..2i.:i:}-;i4,:i8, 19,113,252

(I'aiinopTt'n) iH-ak-yi 2<)-29,

;iH, 49, Cui, t;.). iw). i08-ior. 108. 2ir,, jis

Ibnifinnui Conral 7ri, 79, 101-102, i.ii

( Li/'trin Ihtrmnnni Dall 75,79, lOl-Kfi

bi-niphilli Dall 16. 2;.2.S-29. 3m. 4S,9). 07-98. 100./0

hn'ici 11 lonld 10

Index.

J*Hkc.

Pecten hericcM var. hindtli Carpenter Ill

hrricfitu var. mivarrhus Dall 112

var. gtrcUegus Dall 1 13

Chtamiff) herireus (loiild 110

var. strategy* Dall 1 13

110

( Chlamys) herieitts var. albidu* Dall

Humphreysii 1-41

(Chlamy) At/d/-/ Arnold 69

inca Orblgn y 1 25

(Pnipfainusium) inequisculptus Tiberl oO

( Propearauniuro ) interradlatiiH Gabb 14,

38,50,5H-54,.~)9,91,7S

irradians 133

//a/ic/im Miiller 114

Iiandtcutt Chemnit 1 U

Iriandicus Cooper 1 14

( Chlamys) lalandicus Miiller 16,

26, 29, 33, 38. 49. 52, 55, 107. 112, 1 1-1 14, 115. 120, .iH

Jeflcrranius Say 78

(ChlamyH) jordan Arnold 26.

29,31.34.38,49, 114-llo.;Jf Pet-ten keep 19, 21, 22. 23, 38. 4S, 60-61. 85, 135, 151,, 156

(Chlamys) landesl n. Hp 14.:<8.49,5l-52,i

laqueatiis Soworby 136

(ChlamyH) latlauritns Conrad 26-27. 2-:W, 33-34. 38.

47, 49, 82, 91, 108, 1 Il>-1 16, 123. 129, 130, 131 , 137, e-W var. cerritenshs n. var. . . 83-34, 38, 49. 108, 1S0-10,

var. deloHin.fp 33-34, 38, 49, 180, ;?;W

var./nif/iVi Arnold 129

var. fucicoluH Dall 33. lis, 49. 130. 181, .'3/;

var. monotimeri Conrad 33-34, 38, 49, 82, 18 1 . e.6'

(Chlamys) lawwml n. 8p 27, 38, 49, 1 17-118, a,'.<?4

lecontpi n.sp 27, 38, 48. 94. 98, 107, ;?iO

(INeudamiwiuni ) lymph'ocnsif) 21, 38, 50, 80, 190, 198

( AmiLsiiim) lomprx-ensis 3, 50, 73, 92-93, JOO

madioninM Kay 141

( LyroptK.lcn) maKUolia Conrad 19,

39. 49, 70-72. 77-79,80-81, 107. 19g, 19U

maijnolia Dall 72

maximus Linne 4K

meckii Merrlam 99

niembranoHus Morton 52

merrianii 27, 39, 48, 99, ;.'0A

meHotlmerlH Sowerby 115

(Lyropecten ) mlgueleni8 ... 19, 39, 49. 79-HO, 102, 188, 190

( Leptopeden ) mtmoiiimris Ci rad 131

(Amiwium) niortoni liaveuel 92

(Plagiot-teninin ) neahenslK 18, 21, 23, 89, 60, H7-K8, 17 U

nevadanns Conrad 141

TK.cadanr/ Conrad 70

( IHoiiwctniiu m) itewwm i A mold 132

49. 129

(Chlamys) nuttcri 19,21,23,27.39,49,67-68,105, /fitf

( iEquipocten ) opereularia Linn 49

(Chlamys) opuntia Dall 27-*29,

39, 49, 91, 107, 116, 118, 128. i'2H

( Patinopecten) oweni 23,

24, 27, 39, 49, 68-64, 65, 96, 121. 160

(Plafioctcnium) pabloontin Conrad 23,

39, 50, 63, 86, 88-89, iw<

(.FxinlpiM-ten) palmeri Dall 39,49, 186-137, i?U

(Chlamys parmeleei Dall 27.

29. 39. 49, 68, 100, 108. 1 19, 120-121, (PlaKiofitenium ) paucicoHtatus Carpenter. 39, 50, 187, i2-2 i-itti/tt Conrad 114

Peoten ( PseudamuKium) peckhami (Jabb 16,

17. 19, 21. 39, 47, 50, 65, 5<-57. 89. 138-199. /.W

( pHeudarausinm) Trask 21,

23, '27, 39, 50, 90-9 1 . 92, 1 16. 123. 138-139. Mt

(Lyropecten) 19,21.39.49,80-81,27.174

( AmnKinm) pleuronectes Linn< 50

pomatla Valenciennes 125

Chlamys) proa vus n. sp 1 1 , 12, 39. 49. 52. 58-68. lis

(Patinopeeten) Conrad 19,

21, 2A. 39. 49, 64-66. 158, inz

pwpatulttt C€oper 101, 106

( Pseiidaniu.oinm ) Sowerby 50

( Patinopivten ) pnrisimacnsifl. . . 27, 39, 49, 62, 106. il2. m

pyxidatUH Carpcnu*r 141,142

( Dall. 89. 50, 89.91, 188-189. ;;iU>

var. n. var 39, 60, 189, iio

i Propeamusinm ) rivers 27, 29, 39, 60, 126-127, 184,

rubidM Hinds 112.113

HanctwcnizenHis 16, 17, 19, 3P, 48. 64-66, 150

(Chlamys) Hespeenwis 19, 39, 49, 69, 70. 160

var. hydoi n. var 19. 39, 49, 69-70, 79, 83, i.54

( Propeamusium ) stanfordensiH 14,

19, 21, 39, 50, 53, 68-)9, 91-92. 190

Pecten Htearnrii Dall 27-29,

31 , 39, 48, 60. 63. 77, 91 , 96. 98. 100, 108. 116. 123, 128. 135. tOS

HUbcrenatns Carpenter 142

(Nodipecten) fubnodoHUs .Sowerby 33-,

39. 49. 107. 128-129, V, 250

{IHuffiortniium) tubrentrirrmu Dall 123, 125, SSt

Kwiftii BemhardI 46,119-121

thala.ssinum Dall 46

lownsendi Gould 142

tnwki Gabb 53

Orblgny 116

fumidwi Sowerby 125

tunica PhilippI 1 15

I Patinopecten) turner! 27, 39, 49, 106. i. J/ i

tutibarcntv' A mold 54

Pseudamuslum ) vancouverenRis Whlteavea 39,

50, 101, 133, 139, 140, Vf

vaughani 19. 39, 49, 81-82, 190

veatchii Gabb ... 27,39.49,98, 106-107. ff

(. IHagifnieuiiim ) rr Arnold 132

vfidricmu Dall 132

trntrii'om* Gabb 182

vrtitricoum Sowerby 123, 125

vogdesl 3:-, 39, 48, 100-101, 135, tio, 21 J

Con rad 74. 75, i&l

(Chlamys) washbumei 27,39,49,119-120.354

(('hlamys) watts 27.

39, 49, 67-68. 96. 119, 120-121, 122, 166

var. moran 27, 39, 49,1 21-122. /64

( Propcasinusium ) way landi ... 14, 16. 89, 60. 53, 68-69, 150

yessoen.sLs Jay 102

sp 59,63,94,117

8. 8. MQUer 41. 46, 48,

Pectens, collection of, exam ination of 8

geologic range of 37-40

localities where found, lists of. 11, 13, 16, 18, 20-22, 26. 29. 32

plates showing IhS-tSO

summary of 44

unidentifiable of 44. 141, 142

value of. in stratigraphy 7

Pectinacea 41-260

Pectinidie 41-260

Pectunculus patulus Conrad 118

Pelecypoda 12, 14, 17, 19, 21 , 22, 28-24, 27, 28, 30, 88-34, 41-260

Indkx.

Periploma nrgentaria (.'onrad M

HP T.t

Periswjlax blakci 12, 15 ,

tricanmtiiN Weaver U j

sp : 17 I

I'etru'ola canlitoides Conrjul 31

eognata ('. B. 31 ,

ienticuliita Sowcrby ;U

Petricolariti coKiiatM H. Adams :J4

Pharoidcsacutilirioatus Conrad 17, 1'.,'22.LM,'27,

jx. 31 , 31. 57, t), 79, 83. M. yft. UM-KlT). 117

calif oniit'iH C'diirad 31,34.95.121

(Toniilata 21 j

outta Hi Con md 27 -2.H. H4, 95

richllKjfcMiJ Gabb 19.79.95. KM '

tHnnifMMilpta Caqxiitcr 31 i

turneri Stanton 12

sp 17. "m. .57. 73, s J, 117

Phufiianclla fomjita liould :w, '

Phobididt*a pcnita C'onrail 31.:5l

Pholadoinyti iiasntH Gabb 12

PholaN crncigera Soworby jj

Phon'us pullijfo Martyn ;t.'i

Physa hottTostropha Say :m\

Pinna alanirdcusis Yatr> 19. 23. S5

Pisaiiia fortis CariMMiter 21, 3r..

Pismo fonnation, ('(inivaU'nis bt

11 . oO

aiidersoni is. 21. 23. 37, 17. rm. 79. S'J-su, ,s-. i<.h; '

var. barkerianus ls-19. 37. 'i). s:i-S4. HfH i

Jabb 2f>. 2H-29, ]

37. 5(). 6;J. 77. Ml. 9H-W, 107. 1 2H- 1 lM. 125. IX\, .'.7J. i.",.'

var. nioiidonhalli 19, i

21 , 2-2. 2:5, 37, ro, iA). ">;i, St-So. .s5. ;.v.; I

circularis ."owfrby :i3-31,

vur. ;i'<iiii.nl'aHii CarpciiliT :J3 31.

desTt i Con nid 19. 2*2. rx), Ho. uk;

t'ldridKoi 23. 24, 3, 5(), S7. /.'/', i

neahorisiv 19. 21 . 23. 39. Sl-sH, i:u ,

pabb M'nsis 23. 39. .'x), ;3. S'i. HH-H9. /.'vs"

IMini-i('o*-taliis CarieiitT 39. ;5o, 1:17, ;.','

filhrt I )iill 123. 125. ,'.."2 '

vt'ntrirtisiiit Pall 132

rfdnniini 90 ,

(rnui-iitti '.H)

I'lanorliis tiiTiii'lu' riiilTr 3("i

Platyodoij ran''llnMi> Conrad 31 '

I'b'istocriii" roi'ks. formation- oi 9- 10, ;;i-37 j

fauna of 3:i-37

orrnrmur of 9. ;!1

of 33. 37 10, 13. '

]M('.'<ia.-tr'a ralifoniica VMnLrhiin 22

r'h'uroioma bartscbi .Xriiold 31. :u;

carprntcriana 'Jabb 117

(MMjperl Arnold :W',

dalli Arnobl 31. 3H

Arnold '.U':Si

Pleurotonia porkin.siana 15

Gabb 28,31,36,103

raricostata (JabI) 17

renaudi Arnold 31, 36

smith! 31,36

t ryon iana G abb 36, 117

17, '28, 30,.91.116,128

IMicatula ! 46

ostrciformis Stanton 12

PliiM-ene roi'ks. fauna (f 26-31

fonnat ion.v 9-10, 25-31

iH-currency.' of r 9,25

PL'Ctons of 2i>-27, 29, 37-40, 42-48,

r2. (A, 77. 91. 91- 127, irt*. lO:,-ir,S, 200, }20i-S2S,g3£-2i2

PiMlfKlcMiius marrosrhi.snia Ht'shaycK 28,80,34

P(]ynir". rc<'lu/.iana 22

I'ornaula.x undosn.< Wood 36

sp 104

Porter. Wavli., roeks near 15

potamidfs carboni'-ola 15

ITienr 28.

31 , ;}i;. 91 , 95. 103, 1 16-1 17, 121, 123

41-250

Gn-jjorio 41,50

alask('n.si> Pall 37. 50,127, lSS-184, 138, S60

clallanuiiHs ]4. 16, 37, fK), 53. 57-58,59, 150

font'stratus Forbes 50

Tiberi 50

intt'rradiatus (Jabb 14. :i8,n0, 5S-54,59,91, i4.S

ri ver-'i 27, 29, 39, 50, 126- 127, 134. S32

slanfordensis 14. 19, 21, 39,50. 53, 5s, 59. 91-92. IfH)

waylandi 14. IG, 39, 50. 58, 5H-89. 150

Protoeanliacentililo.'a Carpenter 31,34

edentula (iabb 19,84

Psephis lonli Haini 30

salmonea Carpenter 34

tantilla Gotdd 34,103

Pseudannisinm II. and A. Adams 41.50

Alaifkt iifis Dall 133

davidsoni Dall 3H, ,50. I'M, 138, fW

exotieus Chenniitz .50

knnpiem'iiMs 21 . 50. 89, 190, 1U8

Ieekliami (Jabb 16-17,

19. 21 . 39. 47. rx). .55, 56-57, 89, 138. 139, 150

jedroanu< 'I'rask 21.

23. 27. 39. rx), 90-91, '.2, llf.. 12.3. 1:W-139, SOO

Dall 39. 50, S9, 91, 18vH-18. 2i0

var. tillamookensis 39. 'tO, I:i9, iUO

vancou\ erensis Wbiteave 39. .5(). Idl. i:i:. 139. 140, iltS

Pseutlocardium K'lbbi Kemond 24

Pieria limula 52

I'terohytjv foli.-itns Martyn 3il

nuttalli Conrad 36

Pteronotus festivns Ilind 36

IMiifet Kfoop. of 10

Puneturella eucuUata (iould 31,36

Kaleata (iould 31, 36

Purixima Creek, Cal.. rotk n-Mr 25

Purisima formation, ebaraeter of 25-26

equivalents of 10

fovsijs (t 26-28

<eeurrenee (.f 9, 25-26

peeteii-of 26-27.37-40

Purpura eanalieulata Inielo 24,30

erispata ChemDitz 28.36.117

sji xieola Valeneienne." 24, 80, 36

Index.

Pyramidella conlca var. variegAtA Carpenter 36

Pyrulaiip 1.117

K.

up W

Range of C*alifomia pectenj* 37-10

See aim fpecir.*.

Recent time, pectons of 37-40, 43-44, 94, 103, 111-114, 116.

RIctazis punctocnplata Carpenter 34

Rimella canalifvra Oabb 16

simplex Gabb 16

Rimoa acutclirata Carpenter 86

Rock Creek I->>cene. eiuivalentj of 10

RoHtellarla imlurata Conrad 28, 106

Rupelluria lamellifera Conrad 34

S.

SallnaM Valley. Cal., formations in

San Diego formation, valonts of

funna of

San Joaquin Valley, fomiHtions in

San Juan de Fuca Strait. near

San Lorenzo formation. <'haraoter of

equivalents of

fauna of

oecurrence of

of 16,

San Pablo Buy. CkI.. nirk.s near

San Pabl() formation, chnnu-ter of

tKlulvalents of

fauna of

occurrence of

pectens of 23,

San Cal., riK'ks from

San formation, character of

equivalents of

fauna of

M'currence of

IKM'tt'ns of 33,

Sanguinolaria nuttalli Conrad

Santa ( 'niz. quadranirle. ro<'k in

Santa Margurita fonnation, e<|uivaIentH of

fauna of

Santa KoNilia. Mex., fossils from

Saxidomas Klbbo*us Gabb 19, 24. 27, :30,

Kracilis <iould 24,30,

.sp.

Page. Septifer bifurcatus Conrad 34

dichotoniUK Gabb 14

Serjmla jp 12

Serpulorbis H<{uamigerufi Carpenter 2S. 36

califomi(;a Vaughan 22

SlgaretUH debilis Gould 28.36

McopuloHUK Conrad 17. 19

HP r,-66

Siiiqualucida Conrad 27.34

patula Dixon 27,28.30,103

9,22

64,83

34,73

Scala bcllastriata Carpenter :

crebricostata Carpenter :<6

bemphilli Dall 'M\

hiiuisii CariK*nti.*r 36

indianornm Carpenter 31 .

steamsii Dall 28.100

tincta Carii'nter 28. :i6

sp 17.117

Scalaria mathevvsoni Gabb ir*

sSrhiaawter lecontei Mi'rriam 12

Stonsia tulwrculatus Gabb l'>

Scutella falrlMinksi Merriani 19. 70, 122

abbi Rcmond -'i

intcrlineata Stimpsou 27, :i(>

Hp 92-93.

Sella awsimilata C. B. Adams , :6

.Semele de<'Lia (/onrad 34

pulchra SSowerby 34, x.'*

var. monterey Arnold 34

on 12,21,53,57

var. nuttalli Conrad.

sp.

Siphonalia keliettii Forbes 36

lincata Stanton 12

Slphonodentalium pusillum Oabb 15

Solariella cidaris A. Adamn 31

Carpenter 28, 31

Solarium amoenum Conrad 17

17,19

Sotemya vcntricoea yo 17

sp 67-58

Solen curtUH (mrad 17

diegocnsis Gabb 14

iarallelu.sGabb 12

sicariu.*<Gou!i 19,24,27,30,31,34,79,84,96.99,108

Htantcmi Weaver 12

Hp 24

.Sooke IjhI.m. equivalents of 10

SpinK*r>'pta pileum Gabb 15

BpintglyphuK lituella Morch 36

Hmithi Arnold 86

SpiHula catilliformiH Conrad 27-28, 34, 67

falcata (Jould 27,30.34

sp 66

FMmUrniih (onrad 71

Conrad 71

Stalagmium concentricum Gabb 14

Stanton. T. W., on Tejon formation fossils 14

Stepbanocoenia fairbank.*!i Vaughan 22

var. columnaris Vaughan 22

Stnitigraphy, value of Pe<'ten genus in determining.. 7

imchecoensis Stanton 12

Stnjmbus granulatus Sowerby 22

sp 22,85

Strongylocentrotus franciscanus Agassi/. 33

Styliferina tenuisculpta CanK*nter 86

Surcula clay tonensis ( Jabb 16

crenatotipira ('( 16

inconstans ( 15

monilifera 15

proeattenmitu (Jabb lo

raricostata (iabb 15

T.

Tagelus califomianus Conrad 84

Tamiosoma gregaria Conrad 23. 24, 64, 76, 111

TajK'M conradiana (iabb 14

cretacea (iabb 14

lacineata Carpenter 34

<iuadrata (iabb 12,14

stamina Conrad : 24,28,80

tent-rrinia Carpenter 27.34

Iruncatii <fabb 19,88

I sp M.

Index.

Page.

Taniiils stroHRi Aniold :{l . 36

Tojon charaitor of 13

faunH of 1 1-15

oceiirrt'ncf of *j,VA

pectens of 1 1, 37-40. 51 . 5 1

Tellina aMiuul 1*. 12

an'tuta 17.

bcxlejrcnsis H iiuls ly, 34

califoriiiiH (;ull 14

congesta ( 'ni rail 20, 21 , 27. 57

hornii 12. 14

ida.- 34. M. 104

U .3.117 . 31. 3i;

loiiga Gabb

martinrzeiisl*. Wi-avrr oregonensiv Conrad ..

rcmondi (Jabb

nibtscens Hanlfv

undulifera (iabb

sp

Terebra cilifomira (labb Himplex Carpenter ... watlslana Coop4'r

Np.

Trebmtnla nite'ronnul

Terebratulina Stunton

Teredo .p 12,

Thalotia calTeii (iabb

Thello'fyla triaiigulata (inbl)

Thnu'ia karquim-fnsis \Vi'avr

dilleri Pall

l"hyaiira bis.--ta Conrad

gouldii rhilippi

sp.

Tivela j-rasatelloidi's Connid

ine/ian.i Conrad r..22

Tornatinu cin-.jliv; <;oull

(Milciblla (ionic

e.xinii.-i Haird

harpa Dall

Traehytritnii (inbb

in.sifjirini' (Jjibb

'I'reu> inittjilli CMiiiiitl 21. 27. ;u.31.

M.

Trilori>' M<'ntMK'U-

cnliii'miriiiM <i.ibli.

fiLvii'iiriiu- <.iill)

gibbnsu>- Hm-liTip

honii (i.il.l.

i.it.h

pidchnnii \V.

wbitnt'vi Tjibl>

l'.'.21.J

Terebratalia smithi 3(>

hemphilli Dall 107

TerebratoUa transversii Si >derby 1 ji ►

. 5S

1. Ui:;

3i.:',4

7'.. S3

Trivia ealifornir.i (iray

rj. 7'.

i:- 103 2J.i;j

M- I'. '3, 101

Page.

Trivia Gray 36

Tiwhita rostellata Connul 17, 19, 79. 3, 117

lilosa (jabb 24. ao. 65, H4, 88. 104

inornata (Jabb 117-

sp 24.9.'!

Vaughan 14

stantoni Vaugban 14

St riatns ( abb 14

zitteli Vaughan 12

Trophon corritensis Arnold 86

gracilis I'erry 31, 36

multieostatii.'* EschM-boll 36. 103

orpbeus var. Arnolil 31,36

Iiacificni Dall 81. 87

]edroaniis .\ 36

ponderosinn (;abb 19,24, M

Stuart i Smith 31,37

lenuisjidittu (arfM-nter 31

triangulat us CariK'Hter 37

Tunnel Toinl b-d, einivalent.s of 10

'Juibinella crassitivsta Gabb 12

sp 52

TiirlHUiilla adler Dall and Bartseh 37

arnoldi Harlseh 37

aurantia Carpenter 37

crebrililata ( 'arja'nter 87

gibboNi CarjK-nter 37

ia.ninata Carpenter 37

latifundiu Pall and Bartseh 37

low'.i Pall and Bartseh 37

niurieata ( it add 37

pentalopha Pall Bartseh i 37

-unilinii< C. H. Alanis 37

'tearnsii Pall and Bartseh 37

subcuspidata Carpi'Uter 37

temiieulii <iouM 37

toppiata 37

lonpiata var. >>tNliiui Carienter 37

tridiMilata Carpenter 37

Turnrr. II. W.. on San Pablo 23

Turris vp 12

Turritella eoniea Wcavef 12

eooperi <'arp.-n!tT 2-s,31.37..5. 100, 101,117

infrngranulata iJabb 12

jew el I i Carienler 31,37

12, 15

Conrad Is. 19.83. M

UNa-ana Conrad 51,. V2

variata Conrad 19

sp 21.30.58

r.

Cnio iK'nultinnj><;abh 14

rpi-yca cnudata (Jabb 12

robu-ta 12

.

Va<|Ueros fornuitioii, charart'T ol iM

ol' 10

lauiia ot" lH-19

or.Mirr.'ii.-e 9.

. ns .,j LS-19, 37-10

Va'iu'ni Valb-y. Cal.. rocks in 18

Vi-neri<'ardiabarbaren.sis Stearns 31,8

2ti4

Index.

Vuiirricanlia plan icOHtu Lamarck U./Vi

VHr. Iioniii (iabb 12.14.51

v.ntri*<Mii Gould a>-31, 34. 100, llT-llx

Hp 57,66

gnidlH Bmderip and Sowerby 31

lenticularifl Gabb 17

neglecta Sowerby 31

pcrteniiis ( labb 19, 24. 27. Tt. 7iJ, S3

Klmillima 31. 31

taiitilla <}(iiild 34

Hp X3-M

Venninilariu Hp 37

Verticordia iiovoiium >suita Adamn and Kcc vc 34

Vitrinolla wllliamsoni Dall 87

I'ttlii drntatuit SowiTby 13ft

floridur HindM 127

Hp UT), 100

Voliitilithes Tu

Voluta hp 2, Wi

Volvarlna carla Soworby 37

Volvula cylindri'a Cariiontpr 37

WaKhington. formations in 10

Whitney, .1. I)., in Martinrx formation 11

on Ti'jon formation 13

Wildcat formation, fMiuivulcntN of 10

Xenophom /.ittell Weaver 12

Y.

Yoldia ooiK-ri Jabb. 1U.27. 31.

imprcMui 'onrad 17, .V>

stiwiirala Dall 27. 84. 103

Z.

ZirpliH-a Kabbt Trytm 27.34

Mp 24

1

I

Cj,

O

So

A'.

.O

"ij.

%,

V'v

'1-

'A

%.

O

'1

c3>

/

r'

H.