CEC ce re ee q 5 CARTE € CECE ROO CC ECC By SSKe Cae \ | CC ra CE CoC é ; HOC COE CCE age NCE A GTC CEE 5 Ca GIRS eer cwe AAR Aan z 3 a: <€ Ca a CG ~ a ~ AAR AY la roy 7 ae | ce & a € ra + <4 CC. © «<é res (Ee « a EGC 6 cee st Uf « iG KCCE GEE EEE eee — Le sa NPP EN pe oN NN AARAARAAARARASE VoV MARA AAT OOOO aA R NAR NO ONIN ear A DONNA a AE | aN a aN aN ARAAY ny ). <> Vm — AAA AN iY WARAS 3 IN bi (E> LNT Yin (™ Noo ARR An AAAS PAN ARO on AARON AANA AAA VARA AAA AAA AAA Aaa lay AANA NRA SAA AN ARAB AAR CAT AWAPA A BS BS es r Nf ‘s BAe a x \V ex \ WANN Vo Veal alaav a BT,RAY rN tdananpnpnannnnnnnns (~~ i Are VAN IX FX > BRA NAR aw ea aa Vt pe \F- GaN CAEN Nee ~~ fF pee ARINOANOe : WANT AN RROCEN a" ARARAAAA D2> AN AA Aak é Va A annnagan emma 2, RN Pate ||| ’ , 7 \¢ ae RS i ise a ae ee ee eee VAANAA AAA VAAAC ping NA AA. TAA x AAAAAY a ae BONA AE El arte Xe 28 3 ; UPR fhe a EN ~ ZEN, ~ fae! ~) ¢ - Aa {~ ALA 2 ‘ 3 ; NP i) f ee j / f AAARAARARARAARA a \ANAINAAA A ps VAAN IONS OR ARIA AARARAARARAR nama aA PY AR a aN EN Ro 2 : YN [NT \ARA apannnay VN AAA ARARAC RO NA, AAR anc PANNN ep mane Ria AAA s AR AAAAA Ae alalaag NaaAaaanaa, ae rs aN Ripial. EXTRA, AG RENN AEN ARGE AAAS z SINAN ARANA ANA ! avax i px BAX QaaA A Naval ay ANA alala TARR. AARRANARORA I -\ (| aR oo a VN ae ae AY! Bee Dy! l~ (~' aN aN NTN a fe are a RAR. PRO N= AA AARRAARA WANA EES PX ps ~ Se ee NENT ON ONM 4 - AAA | ala y SACRE STAVES : ARS AAA Ona annNAAAAn aan SAAR AAAS RARRABRARRARARAAAAANN AZ -paceeet RAs bes AAA A AAR A = DAA AAA ale AAA IN NAVAN av aA AWAA - a AL SAAN AANA AANARAAAAAAVA an Da a2 aRARARANY YAN — oS = NEN i GN Bea OR iS wes soot ane AAAA ana ran aN An RAARA RAR Ba | \A SAR Jap ABR RRRRRRAALA . 7 7s il la NaN o an . , 4 ‘ . ' i ns , . ao pe - ¥ : ’ =Y ot s Professional Paper No, 47 Series 0, Systematic Geology and Paleontology, 76 DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY CHARLES D, WALCOTT, Director Ee TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA BY =anerl Libr ary Re geen” -ASEGIN| ©xPo a) WASHINGTON GOVERNMENT PRINTING OFFICE 1906 215314 CONTENTS AND ILLUSTRATIONS. Page. TINTRO DHCIION eee eee Ne ae Ato an re Ga he Ee Se Nee aoa ce bic de cece bees sas 7 Part J. THe Tertiary AND) PLEISTOCENE FORMATIONS OF CALIFORNIA ...--.-...----.-------- 9 Rost-Cretaccoussgenlopier collin sss emanate ee eee san eso el alee aes ete e =e 9 ROSIE CrelaceGusa CORE ail Onmtul epee eee eee Saas Haale cineca eee cet eas cece ce 9 Ie Qar Ce = Beene H/Lbnt SER ESR RSS SORE A ale Seer, AS A Ce ee eg eee ea 10 Martinez Morman onesssere ets ee ee aoe aan cee ea nil eioe nieces cele see cnsawd fee 11 SLY pes lOCRlIhymemeMemeer eee Se eae te seams Se ne SAM see sabes ie techs ole 1] Nannesandndeserminnongrrr a. Asti are cap Aen is one e meno oe Se eee oe soos 1] Deh mi tiGn Ae ae eee ee ter, = eyes eee Meret! ol ee see 11 Joye TTR as eS SL he ae ei ee See a ee 1] DENS OVS AR ee Ne poe a Se ee 11 Rectenkinnnneeres ecm aey tons ore orks ae eetemines oe acca de ke oecess 1] List of Martinez formation (lower Eocene) foss 12 MejonyTorma blo ntys sea eter ree oie ele ene ee Ser Sodio acd sccann 13 iyspey OCaE Vere emetsseeerseaey a ass = 2 ysis ee erate elo ce cj oes oe Dees ce 13 Nam erandtd eserip tonearm esa oan ae asec a ee ties so oce Sac ceine cee eceee 13 ADYeNa Baal roy Ne eas ae aa SS I a ae NS | SR Co ee 13 EO CALL TICS eye eer ee ren ce ee Sf 1h Re ee es ek Sele oe 3 UE Dey i ree UE em Sele ma SS cna Ra 14 Recte np fatin apeees oe ee ear 5 SW nes et eee Neh ey oe eee 14 list ots Lejonmtormeanionm ¢Hocene)) fossilss= = see sees as see aoe nos] cease sees 14 GD OCET CS ee eee ee oa eee NG eee Se Wess aE bis Dade so eeeeee 15 San Oren ZOMLO ural Ores eee Sak caro, en eee Ree ee tere! SOS hel eee ee 16 FRY PERLOCALi type ia eee ee tis cote ae a cree ae CE ee ee seek 16 Definition eer tee ee ere as Se ee ee es eS he See eee as 16 TEGCALUTCS mene Seer nein Sec Ae Shah sane a at Mi Meee en ab Se 16 VERE TOs ea eS a a a eT a 8 Te aS ee Dore 16 Rectenwiaan aesere pets stots 2 ors ean ese: Seen so AS a RE ee 16 List of San Lorenzo formation (Oligocene) fossils...........-..-.---------- 17 VINO CEN Case Se ees ra ete Fae ES Bene eee et te Den tone SE aioe oc SR SR ES 17 AVI UEOS SAN StON Gy saerast este as oe neice Semone tem aac tsates ice smiseiciee keels 18 ‘gb ofey: hope Se a ers OE eS IRR eno ae ac See eRe aes 18 INAMeEIATIORASSCHI PU OL seen eae e - - eee eo ete ees Be es ee eee 18 TDYSS SANG HOE! eet es eh es 8 ae AN oe Dan pe nr Pe RE Ces Se a eS te 18 To Oe TASS Se aa es i a et ER a le a eR ere 18 SVT TT Meer eae eee a gf! Reet ee Nee SOUS ee be eee 18 IRECTOMM TAU Ae Oct ats Soran tie tp tee tip ARS Owe Ak ko Se 18 List of Vaqueros sandstone (lower Miocene) fossils........----------------- 19 MON Tercyasha lee ast meme SS a mee MN Ane eRe ce Pe We. bss oS geen eens 20 cy newlOcalityesasar ee meree eee men ae oe Pek bok ie eS 20 Nam eran (kG CSCI LLO Lge ee aan aera eee i pene Ye EL ke eee 20 TV STITL ETO Kips es ae esas NA perp Nea tent WS. Ro ae Lae ansemieticnees 20 Ibe MM Ssh ea Sok GUA RES CEU See ae ot ee ee ee Aes Ieee 20 4 CONTENTS AND ILLUSTRATIONS. Parr Il. Toe TERTIARY AND PLEISTOCENE ForRMATIONS OF CALIFORNIA—Continued. Miocene—Continued. Monterey shale—Continued. AUN 2s ce Sea See oe eaten hae Sea ee ASS ais Se Ete oer eet a ae List of Monterey shale (middle Miocene) fossils -........--..------------- List of fossils from the Carrizo Creek beds (Miocene) -....----..---------- San) Pablolformationien. 2 2. o- =. == 23 See ete ee eran See eee eee eet Ty pei locality 22 twats aa ee Se eee ee te tele eer ere Namezanid descriptions es see ete eee ee te a aes See Re en et ee eee Definitloniee esse Seas Se eee cae SRI Te oe Toe a te ata soe ae ae de Pecten fauna asa. eee eos ae ee eee een oes nat te le List of San Pablo formation (upper Miocene) fossils-- - - List of Santa Margarita formation (= San Pablo) fossils from Salinas Walley and!'southward <2 tse sans tars ee ees Sn eee ete Serer POR OTIS pe ee = Fare ww areas sree ete ra rete I ePIC eR net tye esd ora Se ae ee Pimisima formation 9.2 52522 s eis aya Ae ener entre ees, Nad Hele Type locality: oon a2 nae asics ae Pee ee oe oa ns cece yee Re eee ier are Name and description -------2.-:2--2 Ree amine Dein eskes Sects REP ale as eee ere DEAN tone se os os Soe eS oe ee Se oreo = 2 Shar ee peepee ea erates RAM cosscc Ss02 eo oie Se oie ee RR te ee Sale en ers Pecten fauna List of Purisima formation (lower Pliocene) fossils ..........---------.---- bistro san Dieco) formation toss sees sees e aero a eee eee ere Merced formation cc ocche sae 5 een Oe a eee Pe IIa SS ae Eee ane Ty pevlocality oe 22 se ccc seen se eee ae See ee Se re ie eal nlta a eeerere te re te INamevand sdescription! 2 scar ee eat eee laa cose os te oe ee eee Mehnibion a. caec << Sc eo cee SN TE eee cee eee aie aes ee nre re eee eases Wiocalities ses Succ Sct ec eae sok ee te eS See te eee ote eens BOT bol hae ne ee ne 2 = tl ne SER Se So Pecten fauna List of Merced formation (upper Pliocene) fos List of Pliocene fossils! from!’ Deadmantlsland. 222: 22-22 e ene Pleistocene merce eee ee = ee ae ee ere ee een ee en ee eee eee SangPedrowtormation: 22 oS. oc a8 Soe sete seas eee cet eae eke eens yas Nererlitn? See eeoseeasodacas=s65sosqssscusnsesecgie sec nekusenedseaseseeens Namesand) deseripbion\-=s—-— ose eee eee eee ear oe = eee eae Mehninionis sso oe Se eee ae ee a ee yan ete Sree cera eee Wocalitiestne.tscsses ces 15 See epee ee eee eee ern Ban ee sae se == see Pecten fauna Z List of San Pedro formation (Pleistocene) fossils.........-------.-------.-- Geologic range of the California Pectens --..-.---_---------------------------=-------- Summary of the range of species and varieties......-.....-----------+.---++----=:-- Parr II. Synopsis AND DESCRIPTIONS OF SUBGENERA AND SPECIES ..-.----------------------- Synopsis ofisubgenera: and “species. ..< 2 - = 22 2-se mene ase cise = nj cients ese etait ale sie fale Summary, of the subgenera and species. ec ae m2 =item = pina a se = lila Deseriptions Olsubgemerayand species! 225 2222 se ae ean ee ee ieee) Genus Pecten Miller ----- Subgenus Pecten s. s. Miller. Subgenus) Patinopecten! Delle 2 2 opt ate a est eet a ttl ine by Subgenus Nodipecten’ Dall --.2 22-52 << ese e noel rie a am alate al Part II. CONTENTS AND ILLUSTRATIONS. Synopsis AND DEscCRIPTIONS OF SUBGENERA AND Species—Continued. Descriptions of subgenera and species—Continued. Genus Pecten Miiller—Continued. Subsenus:ChlamysmBolvensesepee sees sae ona cece coc n sn deascesees came Subsenuctliyresectens Conralyameaeameern steno. es. 0s ee Subpenusy Al uipecten sHisch Glarere ree mer = icpaa a (ace ois coe oe eee eens Subgents@rlaciocteminmpt a leer eee eee closet an ene nee eeecee se aee Subgenus#escudamustumisheand) AcoAdamssee eso 25250. .f. so sess ss clenes cece Subrenus earn Malu MSO] Lenmar ss er aeae ters poeta ac si aim << one sce ee sees SubgenussbropeamusiammGnrepOm0 ssn esa ean cere stem encase teee cs ne Soeccesses HUbSenus#e uM Level) ciran COge ec ran aes ene sea aeee tao week a Henle t ka rek cle HocenePReclen seme st pene es a ace es eee alee ee Nee cise ial nectar se bode cescce se (nga leeks Soo 32 Soca S odes se oses ees Soacsboc ese a Sea URES Dee SEeeeeeneEsss Where aa(eyd Serene has Sa Ae Ee Oa eC ees OOS e ESC Ee a ea ee IPM OGeN eRe GLEN ee eeee cern te = See amet tenn Ss cle toe ihe Sw asi toes oso a shi’ Pleistocene sPectens mare et rer a= eae a renin ete wlan adsl secieia co sete Seis lces bowen ens IRGCeUim Re Clone sae ere eam enue emits icc es ctisis cece aci@bceeciccee- sks Unidentifiables Rectenseesater pees taee eet cocina nse Sees e eee sees tee es cee ci Tb) o) biay=9 9) oly fs ee ae Se a oe Oa 9 Se AB SOE See Ae ee ee eee PLATES ~ INDEX... PrLare I. Il. III. IV. AYE Wile Walilis VIII. IX. Xx. XI. MIL O00 XIV. KV. XV IE XVII. XVILE XIX. XX. O65 XI. XXIII. XLV. XV. Sketch map of California, showing the principal fossiliferous Tertiary localities... Pecten calkinsi n. sp., P. landesi n. sp., P. proayus n. sp., and P. interradiatus Gab bree 26 eae eee eat ones arc a eee nese sie euos Sic c cent ees Pecten clallamensis n. sp., P. waylandi n. sp., P. peckhami Gabb, P. branneri NSp-, ands Pysanctecenuzensigni., SPL at sossm- asses ee-see aa sea ece mee neec oats Pecteny carrizoensisimsspandvbscoalingacnsis nySpesss22 sees -- <2 ee eee sees 2k Pecten keepi n. sp., P. dilleri Dall, and P. sespeensis var. hydei n. yar-.........-. Pectens keepin ssp and. ee COOseusIs) SHUMALG eeseaeaasee ees eee cea nee ce oe Pecten propatulus Conrad and P. coosensis Shumard.......-....-.---------------- Bectenvowenlintcsp.and vb ses peensismuSpeea. esse ser neinca ese oie 2 ae ane Rectens propatuliispConradesst see ceca. =: aac cee eee emnaeenericin=- occ wceae cies Pecten) tucanus Dallfand sks watts! Var miorani ns var se. ---5-+5--2s--a=-------- Pecten wattsi n. sp., P. hamlini n. sp., P. nutteri n. sp., and P. crassicardo Conradivarsalannal tomignmny ates ose sass psoas peer se ee ee te ecco 2 Lae SE IPECLEDS DOW GTSIbTRES ieee Et pce ees ey meee Ny ine Soe SLM dae Recten bow ersignms Dien = ses eae ec ace see eee eee etieiee coe ooes cae - we ctioecee REGIE PeLrUay Dae Sp teas eae Sees Sacer sete eee Reta oes ccc be Becten) perriniim-rspsrand: > meahensigint spi. so- eo.) vae ee ace cs sece cece ene RECLENG CLASSICALG OM CONTAC Sse ee ees ates Mae io Rian Soe eee eee en see cee secs coabesee Pectenwerassi candor Conta de ceeerer a wena ioe ase meeteee ase ence oe me os ccael sae IRECLENE Cassi Cand On OnTa Cuts sen, same knee ee Noa min See SoU ca cSd at ee oe Rectony estrellanusi Contrada sstue nets sas sdne yasmin oo See aecss cele ences sane ae Pecten estrellanus Conrad and P. estrellanus Conrad var. catalinse n. var ......-..--- Bectengestirellanns OGNTAC aso ease eee eae TA ee ee cts cic See hom asi edianceeerens Rectenemigue leMsisun asp mesa ee eree see es ne See aa = oan ce Sania se ome Se amence re Pecten miguelensis n. sp., P. estrellanus Conrad var. terminus n. var., P. vaughani Dy Sp-,-k..Staniordensis a. sp:, and) b> dompicoensis n..Sp.---.. ------- ore ate eae ee ee Pecten vogdesi n. sp., P. auburyi n. sp., P. hemphilli Dall, and P. lecontein. sp- Pecten vogdesi n.sp., P. auburyi n.sp., P. purisimaensis n. sp., and P. turneri Pecten healeyi n. sp Rectenthealeyinn spy =e = ea ees eer ee ao elses eae ee iPectenvcaurinus) Gould ese ses eee ee eerie ne reece eae ees See Pecten caurinus Gould and P. paucicostatus Carpenter .....----.--.----------- leteeuayal YC NKe (CE O)0) = Sam omen Sab Act Res eGSPERBEecosba se sbserSceaeeose Pecten parmeleei Dall, P. opuntia Dall, P. bartschi n.sp., P. hastatus Sowerby, and P. bellilamellatus n. sp Pecten hastatus Sowerby and P. circularis Sowerby ....-.-..------------------ Pecten hastatus Sowerby var. nayarchus Dall, P. hastatus Sowerby var. hindsii Carpenter, and P. hastatus Sowerby var. hericius Gould. .-.-........-------- Pecten jordani Arnold, P. hastatus Sowerby var. strategus Dall, P. cerrosensis Gabb, P: circularis Sowerby, and iP. riversi n: sp... -2---2e----2-2---------- Pecten islandicus Muller, P. washburnei n. sp., and P. lawsoni n. sp..--------- Pecten excavatus Anton, P. latiauritus Conrad, P. latiauritus Conrad var. monoti- meris Conrad, P. latiauritus Conrad var. cerritensis n. var., P. latiauritus Conrad var. fucicolus Dall, and P. latiauritus Conrad var. delosi n. var....---------- Becteniashleyil mess peacoat eee eee syste hes) sliced Sree rere ee ee Pecten ashleyi n. sp., P. randolphi Dall, and P. randolphi Dall var. tillamookensis n. yar Pecten ‘cerrosensis.Gabb and P.\cooperi n. sp_--.------ 55-22-26 === 2---= === Pecten circularis Sowerby var. zequisuleatus Carpenter, P. palmeri Dall, and P. davidsoni Dall Peevanecouverensis' Whites yess. oa seme ee ate Seren Sere opr a eer eae ale Pecten subnodosus Sowerby and P. alaskensis Dall......-.--...--------------- Pecten circularis Sowerby var. zequisulcatus Carpenter; right valve, exterior - -- Mathersame serie h tival ye: ter Osama eater ee te ener U.S.GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL.I j . EXD q yy / : Fac : hae : > ( : + WY PARTIAL LIST OF | { 5 te, pe Y f EI - f U a FOSSILIFEROUS TERTIARY LOCALITIES \ [napa Riker Bi oL8 Ptst on 7 NORTE iL j + ‘scent City: AT) We , ey = E EOCENE (MARTINEZ) GAN MATEO LOB ANGELES BAN DIEGO. EOQOENE (TEJON) OLD FORT TEJON (GRAPEVINE CREEK) BAN EMIGDIO CREE MARYSVILLE BUTTE! MERCED FALLS. SOMERGVILLE MEW 1ORIA. U:M BO : Winnemycca# Soyer sae SAN LORENZO RIVER. SIOANTA oRUE MIOCENE MOUNT DiABLO_- “CONTRA cOBTA TONGAN MATEO. SAN LUIB OBI8PO poso (pcoya creek DARKER RANCH (KERN Ri SAN MIGUEL ISLAND ~~ GESPE ONL DISTRICT SANTA MONICA MOUNTAING PAGADENA.—— LOS ANGELEC EL TORO - ~---- ORANGE CARRIZO OREE: ~- SAN DIEGO. ~ = _SONTRA copra es ae ctho S ore ny \ SLERRA No ile if is : ; SURO Perec =e oO ~~ Ir eid Pe. - eno 4 Nragcaeno cas Alton poco pomewile, |) em / $Stillwater beg aie Pi f 1 McKITTRICK DISTRICT — —Sr Sree BES SAN PABLO DA ~GONTRA COBTA WALHUT OREEK an “ ecorr vaccey (1) = SANTA CRUZ GAN LUCAS ~— MONTEREY BAN AROO “ GOAUINGA : FRESNO SANTA MARGARITA —=---SAN LUIS OBISPO Ssp: RGTRELLA ——-- ~~ Paacemac fe L DO RAD 0 ~ . / 2 GANTA CATALINA FSUal LOS ANGELES pPlaterville ORL NORTE EEL RIVER (Rio CELL) HUMBOLOT Belmont ® PURIBIMA.. --— SAN MATEO Ry B x boR Sore ate mene 5 ) {ves pivkso™ ss ex © ; ei seott ote Seco Soke Sener ney Pt Tomales} (a \ A Rezo CoN SS Lewis CREEK.— peti ; Zeinab ie A : Seen eeuey We ten | Candelaria CABMALIA.—— SANTA BARBARA +, Waa ; ( . aes ule iq las AMGRLES NES 2 i i rae . O8 ANGELES. - 5 op P¥de los Reyes] Wai < be a CMNEY _Moxer - : Fetwano. TunNe. ; moon ; q : OLINOA (PUENTE MILLE “oom [PI Bonita SS ' \ m Ve, jsosmrt Se if 7 LAKE MERCED BLUFFS ze SAN MATEO . POOR, (wanonD) NY [ Vy fotdensos ne Vigne atk —Tiaxtionan)_;, | ; Tee mi aa LT LAKE (STANFORD UNIVERSITY) ~- SANTA GLARA PITOLA GANTA ORUZ GANTA BARDARA GANTA BARBARA VENTURA. =~ - VENTURA SAM JUAN GAPIBTRANO Z - --ORANGE SAN DIEGO —— “3-2 =: <- SAM DIEGO : ~-BANTA cAUZ P BUMMERLAND = SANTA DARDARA 78 LONG BEAGH - — > ~-- LOR ANGELES 7” NEWPORT - ORANGE 60 PACIFIC BEAC ~~ SAN o1eGo 1 SPANISH DIGHT- cane iy Iqpterey XE Pts iy aS Pt'San Luis 0 R “—“Anacapali | Ros oat if g Santa Monica Bay San Miguel | 8 2 MAP OF > 1 7 > | CALIFORNIA Santa Barbara |). anta Catalina| SHOWING PRINCIPAL TERTIARY AND 4 Santee A. \/ ans Nichola PLEISTOCENE FOSSILIFEROUS LOCALITIES Oceanside ri ate The red dots indicate tossiliterous localittes or regtors. —\- The correlations agree with the correlation tablein | the text and are tentative Seale San\Clementell AMOEN & CO BALTIMORE THE TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. By Ratpn ARNOLD. LENA O DW CLIO, 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 described, their salient characters, where they and their supposed equivalents are known to occur, the species of /%cten 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 range 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, (4) 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 contem- plated when the work was first begun. ‘The original plan was simply to monograph only the fossil Peetens of California, but as the work progressed it soon became apparent that the original subject could be thoroughly treated only 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 paleontologic material from the west coast was undertaken. Then, that the data thus obtained might be 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 char- acteristics, geographic range, and faunas of the different Tertiary formations. It was obvious that any scheme of classification of the Pctinidx based wholly upon specimens from the Pacific coast would necessarily be disconnected and unsat- isfactory. It seemed advisable, therefore, to adopt some system which was founded > i 8 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. upon material from a much wider geographic range. Doctor Dall’s 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 consider- able amount of west coast Tertiary and living material. Dall’s 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. Hecox, Santa Cruz, Cal. Mrs. Blanche Trask, Avalon, Los Angeles County, Cal. Mr. F. L. Button, Oakland, Cal. Dr. J. J. Rivers, Santa Monica, Cal. Mr. J. Howard Wilson, Yonkers, N. Y. Dr. Stephen Bowers, Los Angeles, Cal. Dr. L. 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. W. 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 photo- graphing. My acknowledgments and thanks are due to Miss M. K. Sumner, Miss Mande 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. eae ed iyer ls soul. TERTIARY AND PLEISTOCENE FORMATIONS OF CALIFORNIA, 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 asa result the greater por- tion 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 only great break in the record, as shown by the faunas of the different forma- tions, 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 forma- tions 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 posi- tion with relation to each other. In general, however, the relations existing between the different formations is that indi- cated 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 formations of California, together with a brief outline of the typical ones, is tentative and based on the information at hand at the beginning of 1905. 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 type locality of the formation, and, in addition, such other species as are found in beds which haye been quite definitely correlated with the latter. These corre- lations are necessarily very broad and are intended only to indicate in a general way the contemporaneity of the strata paleontologists. Owing to the imperfect state of our knowledge af ov | liocene, p Miocene. Oligocene. Eocene. San Pedro, 1,000’ Merced, 5,000’ +. Purisima, 800’ + San Pablo, 1,500-2,000/. Monterey, 2,500’ +. | Vaqueros, 3,000 +. | San Lorenzo, 2,300/ +. Tejon, 4,000’ +. Martinez, 1,000-2,000’. | | Pa || | | Chico (Cretaceous). The Tertiary and Pleisto- ecene column of California. in question. The names used in the lists of fossils are those TEESE ea % a = NO 2 — PU ines repre- commonly applied to the respective species by the west coast sent unconformity; broken lines, conformity. regarding the nomenclature of the California Tertiary fauna, there is a probability 9 10 TERTIARY AND QUATERNARY PECTENS 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 formations of California to 1905. a Oregon and Wash- | Northern and Central Salinas and Southern . See Epoch. ington. California. San Joaquin valleys. | Southern California. pe ae | us a2 sis z Pleistocene. | Coos conglomer- San Pedro forma- ate. @ tion. (Merced formation. | Paso Robles forma- as) . | tion. ie W ildeat forma- | Deadman Island | Mytilus beds. @ tion. | Pliocene, | ers , : Pliocene | | San Diego forma- 0 7 tion. | 4 Purisima formation.| Cholame Valley ord beds. Transitional. ae ie ars a" ue ee | Sooke beds. @ San Pablo forma- {Pismo formation. San tion ; ; Empire beds. @ : : : ‘atalina Miocen mnP. Santa Margarita C a Miocene. formation. Contra Costa Coun- Carrizo Creek ty Miocene. beds (?) Miocene. Astoria sand- | Monterey shale. | Monterey shale. | Monterey shale. stone. @ | | Vaqueros sand-| Vaqueros sand- | Pasadena Miocene. stone. stone. | Tunnel Point | beds. | F San Lorenzo forma- | igo - ae ar ; Oligocene. Astoria shales.” | tion. | | Aturia bed.@ 7 Arago formation.“ .Tejon formation. Tejon formation. Tejon formation. wocene, ‘ 2 ‘ S a Puget group. @ Martinez formation. Rock Creek Eocene. aDall, W. H., North Am. Tertiary horizons: Eighteenth Ann. Rept. U. S. Geol. Survey, 1898, pt. 2, pp. 323-343. Norr.—The author disclaims responsibility for those names in the aboye table which he does not discuss in this paper. EOCENE. At least two horizons 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 by the richly fossiliferous beds exposed in the vicinity of Little Falls, Lewis County, Wash. The last-mentioned horizon is probably 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. 1D MARTINEZ 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 deseribed 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 by 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 faunally only distantly related, it is probable that an uncon- formity exists between them. Though satisfactory correlation of California forma- tions with the subdivisions 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, Pacheco, and Army Point (near Benicia), Contra Costa County. Lower Lake, Lake County. Between headwaters 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, Pecten (Chlamys) proavus n. sp., and this from a locality of doubtful Martinez age. avour. Geol., vol. 5, p. 775. TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. The fauna of the Martinez consists essentially of the following species: List of Martinez formation (lower Eocene) fossils. [Those species followed by (L) are found in the lower beds at Martinez; those by (U), upper beds at Martinez; those by (B), beds at Benicia; those by (C), beds at Lower Lake; and those by (P) outcrop on ridge between headwaters of San Lorenzo River and Peseadero Creek, San Mateo County.] FORAMINIFERA. Foraminifera nummuloid (U). Foraminifera, 3 sp. indet. (L). ANTHOZOA, Flabellum remondianum Gabb (LBC). Trochocyathus zitteli Vaughan (L). ECHINOIDEA. Cidaris (?) spines (P). Schizaster lecontei Mefriam (LU). BRACHIOPODA. Terebratulina tejonensis Stanton (BCP). Terebratula (?) n. sp. (P). PELECYPODA. Area biloba Weaver (LU). Cardium cooperi Gabb (LU). Crassatellites unioides Stanton (C). Cuculleea mathewsonii Gabb (LUBC). Glycymeris yeatchii Gabb var. major Stanton (C). Leda alzeformis Gabb (BC). Leda gabbi Conrad (LUC). Lima multiradiata Gabb (C). Meretrix sp. (LB). Modiolus merriami Weaver (LU). Modiolus ornatus Gabb (UC). Nucula truncata Gabb (LUB). Ostrea (cf.) idriaensis Gabb (P). Pecten proavus n. sp. (P). Phacoides turneri 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 zequalis Gabb (C). Tellina hoffmanniana Gabb (C). Tellina martinezensis Weaver (LU). Tellina hornii Gabb (UC). Tellina undulifera Gabb (UB). Teredo sp. (L). Thracia karquinesensis Weaver (U). Venericardia planicosta Lamarck Gabb (U). var. hornii a Compiled from lists by Merriam, J. C., Jour. Geol., vol. 5, 1897, p. 773; Stanton, T. W., Seventeenth Ann. Rept. U.S. Geol. Survey, pt. 1, 1896, p. 1025; and Weaver, C. E., Bull. Dept. Geol., Univ. of Cal., vol. 4, 1905, No. 5, pp. 110-111. GASTEROPODA, Actzeon lawsoni Weaver (LB). | Ampullina (cf.) striata Gabb (UBC). Architectonica tuberculata Weaver (U). Brachysphingus liratus Gabb (UBC). Bullinula subglobosa Weayer (U). Cerithiopsis alternata Gabb (C). Cylichna costata Gabb (LC). Dentalium cooperi Gabb (LUC). Dentalium stramineum Gabb (U). Discohelix californicus Weaver (1). Ficopsis angulatus Weaver (U). Fusus vequilateralis 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 (1). Perissolax blakei Conrad (B). Perissolax tricarnatus Weaver (LUBC). 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 pulechrum 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). Urosyea caudata Gabb (LUBC). Urosyca robusta Weaver (L). Xenophora zitteli Weaver (1). CRUSTACEA. | ae Cancer (U). . Crustacean remains, macruran (U). EOCENE FORMATIONS. 13 TEJON FORMATION, TYPE LOCALITY. The type locality 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. x *#D “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 Buttes, Sutter County. Merced Falls, Merced County. Martinez, Somersville, Clayton, and Marshs, Contra Costa County. New Idria and Griswold, San Benito County. Coalinga and San Joaquin coal mines, Fresno County. North side of Sisar Valley, Ventura County. North side Santa Ana Mountains, + 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 Lower 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 localities, according to Diller (1896): Nehalem River, 5 miles east of Nehalem, and also midway between 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, Cooper’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 Roseburg. Marshfield, Jordan Point, and Cape Arago, southward to near mouth of Coquille River. 14 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. FAUNA. Pecten fauna.—The Pecten fauna of the Tejon group consists, so far as. n. sp., 2. landesi n. sp., and P. inter- The first two probably belong to the subgenus Chlamys, but are not closely allied to any of the subsequent members of this group, so far as P. interradiatus belongs to the Propeamusium group and appears to be the precursor of such forms as P. stanfordensis, P. waylandi, and P. clallamensis. The following species have been found in the Tejon formation in different known, only of three species, P. calkins? radiatus Gabb. known. parts of California: List of Tejon formation (Eocene) fossils. @ (Those marked with an asterisk (*) have been found at the type locality.] ANTHOZOA. Flabellum californicum Vaughan. Flabellum remondianum Gabb. Trochocyathus californicus Vaughan. Trochocyathus stantoni Vaughan. Trocboeyathus striatus Gabb. PELECY PODA, *Arca horni Gabb. Astarte semidentata Cooper. *Axinea cor Gabb (=Glycymeris id. ). *Axinea sagittata Gabb (=Glycymeris id. ). Barbatia morsei Gabb. *Cardium breweri Gabb. *Cardium cooperi Gabb. *Cardium (Levicardium) linteum Conrad. Corbula alzeformis Gabb. *Corbula horni Gabb. Corbula parilis Gabb. Jorbula primorsa Gabb. *Crassatellites grandis Gabb. *Crassatellites uvasana Conrad. Donax latus Gabb. *Dosinia elevata Gabb. *Dosinia gyrata Gabb. *Leda gabbi Conrad. Lima multiradiata Gabb. Lucina? cretacea Gabb. *Meretrix californica Conrad. *Meretrix horni Gabb. *Meretrix ovalis Gabb. *Meretrix uvasana Conrad. *Modiolus ornatus Gabb. *Mysia? polita Gabb. *Mytilus ascia Gabb. aCompiled from lists by Cooper, J. G., Seventh Ann, J. G., Bull. California State Mining Bureau No. 4, p. 39 et PELECY PODA—continued. *Mytilus humerus Conrad. *Nucula truncata Gabb. Ostrea appressa Gabb. Ostrea idriaénsis Gabb. *Septifer dichotomus Gabb. Solen (Hypogella) diegoensis Gabb. Stalagmium concentricum Gabb. *Tapes conradiana Gabb. Tapes? cretacea Gabb. *Tapes? quadrata Gabb. *Tellina californica Gabb. *Tellina horni Gabb. *Tellina longa Gabb. *Tellina rémondi Gabb. Unio penultimus Gabb. Venus zequilateralis Gabb. *Venericardia planicosta Lamarck. *Venericardia planicosta var. hornii Gabb. GASTEROPODA. *Acmeea tejonensis Gabb. Amauropsis alocata Gabb. Aneilla (Oliverato) californica Cooper. Ancilla elongata Gabb. *Architectonica cognata Gabb. *Architectonica horni Gabb. Bela clathrata Gabb. Bittium longissimum Cooper. Brachysphingus liratus Gabb. Brachysphingus. sinuatus Gabb. * Bulla horni Gabb. *Bullia (Molopophorus) striata Gabb. Cancellaria irelaniana Oooper. | Cerithiopsis alternata Gabb. Rept. California State Mineralogist, p. 271 et seq.; Cooper, seq.; Stanton, T. W., Seventeenth Ann. Rept. U. S. Geol. Survey., p. 1021 et seq.; Merriam, J. C., Jour. Geol., yol. 5, p. 771. OLIGOCENE FORMATIONS. List of Tejon formation (Eocene) fossils—Continued. GASTEROPODA—continued. *Conus horni Gabb. *Conus rémondi Gabb. Cordiera gracillima Cooper. * Cordiera microptygma Gabb. *Cypreea (Luponia) bayerquei Gabb. Cyprzea (Epona) mathewsoni Gabb. *Dentalium cooperi Gabb. *Dentalium stramineum Gabb. Diodus tenuis Gabb. Drillia ullreyana Cooper. *Enspira alveata Conrad. *Fasciolaria io Gabb. Fasciolaria leeviuscula Gabb. * Fasciolaria sinuata Gabb. Ficopsis cooperi Gabb. * Ficopsis horni Gabb. Ficopsis rémondi Gabb. *Fusus californicus Conrad. *Fusus diaboli Gabb. *Fusus martinez Gabb. Fusus supraplanus Cooper. Galerus excentricus Gabb. Gyrodes dowelli White. Loxotrema turrita Gabb. *Lunatia horni Gabb. * Lunatia nuciformis Gabb. Lunatia shumardiana Gabb. Mangilia saturalis Cooper. Margaritella crenulata Gabb. Megistostoma striatum Gabb. Mitra cretacea Gabb. Mitra simplicissima Couper. *Morio (Sconsia) tuberculatus Gabb. Nassa antiquata Gabb. *Nassa cretacea Gabb. GASTEROPODA—continued. * Natica uyasana Gabb. *Naticina obliqua Gabb. Neptunea (Tritonofusus) cretacea Gabb. Neptunea? gracilis Gabb. Neptunea? supraplicata Gabb. Nerita (Theliostyla) triangulata Gabb. Neverita globosa Gabb. * Neyerita secta Gabb. *Olivella mathewsoni Gabb. * Perissolax blakei Conrad. Pleurotoma perkinsiana Cooper. Potamides carbonicola Cooper. Potamides? davisiana Cooper. *Rimella canalifera Gabb. Rimella simplex Gabb. Scalaria (Opalia) mathewsoni Gabb. *Siphonodentalium pusillum Gabb. *Spirocrypta pileuam Gabb. *Surcula claytonensis Gabb. Surcula crenatospira Cooper. Surcula inconstans Cooper. Sureula monilifera Cooper. Surcula preeattenuata Gabb. Surcula raricostata Gabb. | *Surcula sinuata Gabb. Terebra californica Gabb. Terebra wattsiana Cooper. *Tritonium californicum Gabb. Tritonium (Trachytriton) diegoensis Gabb. *Tritonium (Trachytriton) fusiforme Gabb. *Tritonium horni Gabb. *Tritonium paucivaricatum Gabb. *Tritonium (Trachytriton) tejonensis Gabb. *Tritonium whitneyi Gabb. Turritilla martinezensis Gabb. OLIGOCENE. 15 The recognition of Oligocene strata on the western coast of North America has been more or less uncertain. Doctor Dall“ has recognized what he considers to be an Oligocene fauna from seyeral 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. Rept. U. 8S. Geol. Survey, pt. 1, 1896, p. 464 16 TERTIARY AND QUATERNARY PECTENS 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 ison San Lorenzo River, 24 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 fine 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 Love 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 stratigraphic position of the formation, it appears probable that it belongs in the Oligocene. veten fauna.—In this horizon we meet with the common Miocene Psew- damusium, P. peckhami, and characteristic representatives of Pecten s. s. and Chlamys, the groups which are so well represented in the later formations. /. (Pecten) sancteecruzensis is quite closely allied to P. bellus and P. hemphilli, which are found in the Pliocene, while in the top of the formation, associated with a transitional Oligocene-Miocene fauna, is 2. (Chlamys) branneri, the analogue and probable precursor of 2. 7slandicus, and the latter’s related forms. P. elallamensis and P. waylandi from the Oligocene-Miocene series of Washington should also probably be included in the Oligocene fauna. MIOCENE FORMATIONS. 17 The following species have been found in the San Lorenzo formation at the type locality, or within a radius of four or five miles from it: List of San Lorenzo formation (Oligocene) fossils. [Those marked with an asterisk (*) have been found at the type locality.] BRACHIOPODA. PELECY PopA—continued. Terebratula ef. nitens Conrad. Venus (cf.) lenticularis Gabb. Yoldia impressa Conrad. PELECYPODA. GASTEROPODA. Arca sp. A. Acteeon sp. A. *Callista angustifrons Conrad. Astyris n. sp. A. Callista sp. A. Bela clathrata Gabb. Cardium (cf.) breweri Gabb. Crepidula preerupta Conrad ?. Cardium (Leevicardium?) n. sp. *Cylichna (aff.) petrosa Conr. or horni Gabb. Corbula sp. A. *Dentalium near substriatum Conr. or cooperi Cytherea (cf.) vespertina Conrad. Gabb. Cytherea sp. A. *Dentalium n. sp. A. Leda, 3 sp., A, B, and C. Dolium? n. sp.?. Macoma nasuta Conrad. Fusus (cf. ) mathewsonii Gabb. *Macoma, 2 sp., A and B. *Pusus (cf.) oregonensis Conrad. Modiolus (aff.) rectus Conrad. Fusus (aff. ) thracius Conrad. * Modiolus n. sp.? *Fusus, 3 n. sp., A, B, and C. Nevwra (aff.) pectinata Cpr. Fusus or Perissolax sp. A. *Nucula n. sp. A. Galerus excentricus Gabb.?. Nucula n. sp. A var. Galerus (aff.) mammillaris Brod. Ostrea (cf.) idriaensis Gabb. *Lunatia (ef. ) shumardiana Gabb. Panopea (cf.) generosa Gould. Natica sp. A. Pecten peckhami Gabb. Neverita saxea Conrad. Pecten sanctzecruzensis n. sp. *Pleurotoma (aff.) raricostata Gabb. Phacoides acutilineatus Conrad. Pleurotoma, 2 sp., A and B. Phacoides (Myrtea?) n. sp. | Seala (Opalia) sp. A. Solemya yventricosa Conrad yo.?. Sigaretus scopulosus Conrad. Solen n. sp. (aff.) curtus Conrad. Solarium (aff.) amoenum Conrad. *Yellina (cf.) arctata Conrad. *Solarium n. sp. A. *Tellina (cf.) oregonensis Conrad. Thracia (aff.) trapezoides Conrad. CEP UORODE: Thyasira n. sp. | Aturia ziczac Sowerby (7). 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 Clypeaster (1?) brewerianus, Trochita costellata, several new species of Modiolus, ete. This last horizon has not as yet been recognized outside of the Mount Diablo Range. aMerriam, J. C., Bull. Dept. Geol. Uniy. Cal., vol. 3, No. 16, 1904, p. 378. 17260—No. 47—06. 2 i8 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. VAQUEROS SANDSTONE. TYPE LOCALITY. The type locality is Los Vaqueros Valley, Monterey County, Cal. NAME AND DESCRIPTION. This formation 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 Emidio 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, Eagle 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 Agasoma 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 Agasoma in the lower Miocene, Doctor Merriam has given it the appropriate name ‘‘Agasoma zone.”“ He has tentatively divided this into two stages; the probably lower of the two characterized by Turritella hoffmanni and the upper by Zurritella ocoyana. No differentiation of the two stages is attempted in this paper. Pecten fauna.—The Pecten fauna of the Vaqueros sandstone or Agasoma zone is a large one and consists of the following species: P. andersoni, P. andersoni a Bull. Dept. Geol. Univ. Cal., vol. 3, 1904, p. 378. MIOCENE FORMATIONS. 9 var. barkerianus, P. bowersi, P. branneri, P. crassicardo and its variety hamilton’, P. (Hinnites) giganteus, P. estrellanus, P. magnolia, P. miquelensis, P. peckhami, P. perrini, P. sespeensis and its variety hyde, P. sancteecruzensis, and P. vaughani. The following species are of uncertain stratigraphic standing; some or all of them may extend into the lower Miocene: P. carrizoensis, P. cerrosensis var. mendenhalli, P. deserti, P. fucanus, P. hamlini, P. keepi, P. neahensis, P. nut- teri, P. propatulus, and P. stanfordensis. The following is the fauna (with the exception of /%cten) found in the Vaqueros sandstone of central California: List of Vaqueros sandstone (lower Miocene) fossils. (Those marked with an asterisk (*) are supposed to be characteristic of this horizon. ] ECHINOIDEBA. GASTEROPODA. Seutella fairbanksi Merriam. *Acmiea n. sp. A. *Actxeon n. sp. A. BRACHIOPODA, - ; *Agasoma barkerianum Cooper. *Terebratella (?) n. sp., A. *Agasoma (cf.) gravida Gabb. PROROuEGODne *Agasoma kernianum Cooper. Astyris n. sp. (aff.) tuberosa Cpr. *Calliostoma n. sp. B. *Chlorostoma n. sp. A. *Conus n. sp. A. Crepidula princeps Conrad. *Cuma biplicata Gabb. *Dentalium n. sp., B. *Fissuridea n. sp., A. *Fusus sp. A. Galerus (aff.) excentricus Gabb. Galerus mammillaris Brod. (?) Megatebennus bimaculatns Dall. Nassa (cf.) mendica Gould. *Natica ocoyana Conrad. Neverita callosa Gabb. *Ocinebra (aff.) lurida Midd. Oliyella pedroana Conrad. *Pyrula (?) sp. Sigaretus scopulosus Conrad. *Solarium sp. *Tritonium sp. Trochita costellata Conrad (?) Trophon ponderosum Gabb. *Turritella hoffmanni Gabb. -*Turritella ocoyana Conrad. *Turritella variata Conrad. Angulus (ef.) buttoni Dall. Area (cf.) canalis Conrad. Arca microdonta Conrad. (*?)Cardium (Trachyeardium) n. sp., A. Chione succincta Valenciennes (?). *Chione mathewsonii Gabb. Chione n. sp., A (very large). *Corbula (cf.) evansiana Shumard. *Dosinia conradi Gabb. *Dosinia mathewsonii Gabb. Dosinia (cf. ) montana Conrad. Dosinia (aff. ) ponderosa Gray. *Glycymeris n. sp. A (very large). Leda taphria Dall. *Leda sp.?. Macoma (cf.) calearea Gmelin. Macoma nasuta Conrad. Mactra californica Conrad (?). Mytilus mathewsonii Gabb. *Ostrea (aff. ) titan Conrad. Panopea generosa Gould?. Pecten (see previous list). *Periploma n. sp. A. Phacoides acutilineatus Conrad. Phacoides richthofeni Gabb. *Pinna alamedensis Yates. Psammobia edentula Gabb. Saxidomus gibbosus Gabb. CRUSTACEA, Solen sicarius Gould. Balanus estrellanus Conrad. Tapes truncata Gabb. | *Tellina n. sp. A (aff.) bodegensis Hinds. PISCES. Tellina sp. *Tivela ineziana Conrad. *Galeocerdo productus Agassiz. Venus pertenuis Gabb. *Lamna clavata Agassiz. *Yoldia n: sp. A (aff.) ecooperi Gabb. *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 DESCRIPTION. This formation was named and described by William P. Blake in Proceedings of the Academy of Natural Sciences of Philadelphia, vol. 7, 1855, pp. 828-331, DEFINITION. In describing the shale bels in the vicinity of Monterey Blake has the fol- lowing 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 porphyritie granite, which forms the projection of the coast called Point Pinos, and is the bulwark of the bay.” The only fossils mentioned by Rlake as occurring in the formation are: Zéllina congesta Conrad, Lutraria traskri Conrad, and diatoms belonging to the genus Coccinodiscus. 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 locali- ties, but at a few it rests directly upon older rocks. In some places the line of demarcation between the Vaqueros and Monterey is very distinct, while at others the beds seem to merge into each 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 eleyation of the shales and their subsequent erosion. As a result of this a line of marked unconformity generally separates the Monterey from the overlying formations. LOCALITIES. Southeast of Pinole, Contra Costa County. Langley Hill and Alpine district, San Mateo County. Castle Rock Ridge, Santa Clara County. Castle Rock Ridge, vicinity of Ben Lomond, Felton, Gibbs, and Santa Cruz, Santa Cruz County. Monterey, Carmelo Valley, and Santa Lucia Range, Monterey County. Big Panoche Creek to Kreyenhagens, Fresno County. Templeton, Atascadero, Lopez Canyon, Point Buchon to near mouth of Davis Canyon, northeast of Arroyo Grande, and other localities in San Luis Obispo County. Northwest of Tulare Lake, Tulare County. MIOCENE FORMATIONS. | McKittrick district, Kern County. Ojai ranch and yicinity, Ventura County. Santa Inez Mountains, Santa Barbara County. San Pedro, Santa 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 mo'ds. Pecten peckhami 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 montereyana and a large, coarse-sculptured Leda. Pecten fauna.—VThe Pecten 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. anderson?, P. crassicardo, P. estrellanus, P. (Iinnites) giganteus, P. pedroanus, and P. peckham i. The following species haye a more or less uncertain stratigraphic status, and some or all of them may extend into or through the Monterey or its equivalents: P. bowersi, P. carrizoensis, P. cerrosensis var. mendenhalli, P. discus, P. fucanus, P. keepi, P. lompicoensis, P. neahensis, P. nutteri, P. perrini, P. propatulus, and [2 stanfordensis. : 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 oj Momerey shale (middle Miocene) fossils. [Those marked yith an astevisk (*) are supposed to be characteristic.] PELECYPODA. PELECYPODA—continued. * Arca montereyana Osmont. Pecten andersoni n. sp. Callista angustifrons Conrad. Pecten peckhami Gabb. Chione mathewsonii Gabb. * Phacoides like crenulata. * Corbula sp., probably new. Saxidomus sp. Cytherea sp. A. *Semele n. sp. A. * Diplodonta n. sp. (aff.) serricata Reeve. | Siliqua sp. *Glycymeris (?) n. sp. | *Tellina congesta Conrad. * Leda n. sp. A. | * Leda n. sp. B. GASTEROPODA, * Lutraria traskii Conrad. Cylichna (cf. ) petrosa Conrad. The fauna of the Carrizo Creek beds, which are undoubtedly 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 cerrosensis var. mendenhalli, p. 85.) 22 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. - Inst of fossils from the Carrizo Creek beds (Miocene). ANTHOZOA, | PELECYPODA—continued. Diploria bowersi Vaughan (Mss. ). | Ostrea vespertina Conrad. Fayia merriami Vaughan. Pecten carrizoensis n. sp. Plesiastrea californica Vaughan ( Mss. ). Pecten cerrosensis var. mendenhalli n. var. Siderastrea californica Vaughan (Mss. ). . | Pecten deserti Conrad. Stephanocoenia fairbanksi Vaughan. Pecten (Hinnites) giganteus Gray. Stephanocoenia fairbanksi var. columnaris | Pecten keepi n. sp. Vaughan. Phacoides (ef. ) acutilineatus Conrad. ECHINOIDEA. Pholas (aff. ) crucigera Sowerby. Jly peas yersi rriam. Clypeaster bowersi Merriam GNI ARONN. PELECYPODA. : Cypreea sp. indet., large and probably new. Anomia subcostata Conrad. Malea (+ Dolium) near ringens Sowerby. Arca n. sp. (?) A. Oliva (?) sp. indet. Cardium (Trachycardium) n. sp. (aff.) quadrige- | Polynices (Neverita) recluziana Deshayes. narium Conrad. Strombus n. sp. (aff.) granulatus Sowerby. Dosinia sp., perhaps new. Strombus (?) n. sp. B. Gastrochena sp. Tivela (cf.) ineziana Conrad. Lithophaga sp. | 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. 118 et seq. DEFINITION. The formation at the type locality consists of a series of sandstones, tufts, 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 County 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, Astrodapsis twmidus Rémond, rest uncon-. formably 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 Pass, 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. Estrella Valley, Santa Margarita and vicinity, 3 miles east of La Panza, Cammatta ranch, Music P. O., and Pismo and vicinity, San Luis Obispo County. Santa Catalina Island, Los Angeles County. MIOCENE FORMATIONS. 23 FAUNA. Doctor Merriam, in his original definition of the San Pablo formation, says: “ “The series of strata characterized by the presence of Astrodaps’s and Seutella (Clypeaster) gabbi 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 formation.” 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, Tamiosoma gregaria, Pseudocardium gabbi, Chorus belcheri, « small Ocinebra, and several species of Pecten 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 nearly one-third are peculiar to this formation, about one- fourth are known also from the Contra Costa County 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, rather than a little less than 50 per cent as given by Merriam. Pecten fauna.—TVhe Pecten fauna of the San Pablo, and its supposed equivalents in age, consists of the following species: Pecten anderson, P. coosensis, P. crassicardo and its variety hamiltoni, P. discus, P. eldridgei, P. estrellanus and vars. cataline and terminus, P. (Hinnites) giganteus, P. hastatus vay. hericius, P. nutteri, P. owend, JE pabloensis, 2; pedroanus. } The following species of more or less uncertain status may occur in the San Pablo or its-equivalents: P. carrizoensis, P. cerrosensis var. mendenhalli, P. dilleri, P. fucanus, P. keepi, P. neahensis, P. propatulus. 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. List of San Pablo formation (upper Miocene) fossils.» [Those marked with an asterisk (*) have been found by the writer at the type locality; those followed by (C) are supposed to be characteristic, and those followed by (L) also occur in the recent fauna of the coast.] ECHINOIDEA, , PELECYPopA—continued. *Asterias rémondi Gabb (C). Macoma nasuta Conrad (L). *Astrodapsis tumidus Rémond (C). | *Mactra californica Conrad (?) (1). *Astrodapsis whitneyi Rémond (C). | Mactra falcata Gould (L). Astrodapsis n. sp. Merriam (C). | Modiolus sp. (C ?). *Mulinia densata Gabb (C). Mytilus sp. (C ?). Ostrea bourgeosii Gabb (C). Scutella (Clypeaster) gabbi Rémond (C). PELECYPODA. | *Cardium (ef.) quadrigenarium Conrad (L). Ostrea titan Conrad (C). Cyrena californica Gabb. | *Pecten andersoni n. sp. Dosinia ponderosa Gray (1). *Pecten pabloensis Conrad (C). Gari alata Gabb (C). *Pecten crassicardo Conrad. *Glyeymeris (+ Axinea) sp. Pinna alamedensis Yates. aMerriam, J. C., 1898, p. 113. 6Turner, H. W., Jour. Geol., vol. 6, pp. 483 et seq., from which a part of this list is copied. 24 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. List of San Pablo formation (upper Miocene) fossils—Continued. PELECYPODA—continued. Pseudocardium gabbi Rémond. *Saxidomus gracilis Gould (L). Solen sp. Tapes staminea Conrad (L). Tapes staleyi Gabb (?). *Tresus nuttalli Conrad (L). * Zirpheea sp. (C ?) GASTEROPODA, * Acmea sp. (C). Bittinm asperum Gabb (L). Calliostoma n. sp. (?) Merriam (C ?). *Chlorostoma (?) sp. (C ?). Crepidula adunca Sowerby (L). Crepidula princeps Conrad ? (1). GASTEROPODA—continued. Fusus (?) sp. (C ?). Litorina rémondi Gabb (C). Litorina planaxis Phil. (L). Lunatia lewisii Gould (L). *Ocinebra (aff. ) cancellina Philippi (C). Ocinebra lurida Middendorf (?) (L). *Olivella pedroana Conrad (L). *Opalia sp. (C ?). Purpura canaliculata Duclos (L). Purpura saxicola Valenciennes (L). Ranella californica Hinds (L). *Tritonium (Priene ?) sp. (C ?). *Trochita filosa Gabb. | Trochita n. sp. Merriam (C). Trophon ponderosum 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 Salinas Valley, Monterey County, and southward: List of Santa Margarita formation (= San Pablo) fossils from Salinas Valley and southward. ECHINOIDEA. Astrodapsis tumidus Rémond. Cidaris spines and fragments of tests. PELECY PODA, Arca canalis Conrad. Area (ef.) microdonta Conrad. Cardium (cf.) meekianum Gabb. . Cardium (ef.) quadrigenarium Conrad. Chione n. sp. (large; coarse sculpture). Chione sp. (medium sized). Glycymeris (cf. ) patulus Conrad. Lima sp. Mactra (ef. ) californica Conrad. Mactra (ef.) faleata Gould. Mytilus sp. (very large). Ostrea attwoodi Gabb. Ostrea bourgeoisii Rémond. Ostrea titan Conrad. Pecten crassicardo Conrad. Pecten discus Conrad. Pecten eldridgei n. sp. Pecten estrellanus Conrad. Pecten estrellanus var. terminus n. yar. PELECY PODA—continued. Pecten hastatus Sby. var. hericius Gould. Pecten oweni n. sp. Phacoides acutilineatus Conrad. Pseudocardium (cf. ) gabbi Rémond. Saxidomus (cf.) gibbosus Gabb. Solen sicarius Gould. Tresus sp. Venus pertenuis Gabb. GASTEROPODA, | Astyris sp. Chorus beleheri Hinds. Fusus (aff.) robustus Trask. Nassa sp. Natica or Neverita sp. Ocinebra (aff.) cancellina Philippi. Olivella (cf. ) pedroana Conrad. Pisania n. sp. (aff.) fortis Carpenter. Trochita filosa Gabb. Turritella sp. CRUSTACEA, Balanus estrellanus Conrad. Tamiosoma gregaria Conrad. TERTIARY FORMATIONS. 5} PLIOCENE. Two more or less distinct faunal zones 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 DESCRIPTION. This formation was named and described by H. lL. Haehl and Ralph Arnold in Proceedings of the American Philosophical Society, vol. 48, No. 175, 1904, pp. 22-24. DEFINITION. The Purisima formation consists of a series of conglomerates, fine sandstones, and sandy shales, with a total thickness of about S00 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 portion 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 examina- tion of a large amount of material from the type localities of the two formations and also from supposedly 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 Pyrisima 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., Proce. California Acad. Sci., ser. 2, vol. 5, 1895, p. 330. 26 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. The greater part of the San Pablo should, without question, be 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. Crescent City, Del Norte County. Eel River, Humboldt 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 formations 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), many 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 com- mon 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 ‘tthe Purisima are peculiar to this formation. Of the total Purisima fauna, about 30 per cent are believed to be extinct. The fauna of the ‘t Wildcat” series of Humboldt County, as determined by Merriam and given by Lawson,“ indicates the probable contemporaneity 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. Pecten fauna.—The Pecten fauna of the Purisima and supposed equivalent for- mations is as follows: P. ashleyi, P. auburyi, P. bartschi, P. bellus, P. bellilamel- latus, P. caurinus, P. cerrosensis, P. coalingaensis, P. coopert, P. dilleri, P. estrellanus var. cataline, P. (Hinnites) giganteus, P. hastatus and its varieties hericius, hindsii, navarchus, strategus, P. healeyi, P. hemphilli, P. islandicus, P. jordani, P. latiau- aLawson, A. C., Bull. Dept. Geol., Univ. Cal., vol. i, 1894, No. 8, pp. 260-261. PLIOCENE FORMATIONS. 27 ritus, P. lawsoni, P. lecontei, P. merriami, P. nutteri, P. opuntia, P. owent, P. parmeleei, P. pedroanus, P. purisimaensis, P. riversi, P. stearnsii, P. turneri, P. veatchii, P. washburnei, P. wattsi, and P. wattsi var. moran. The following species have been found in the Purisima formation at different localities in the Santa Cruz quadrangle: List of Purisima 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 (/) are still living.] ECHINOIDEA. Astrodapsis n. sp. Merriam. Scutella interlineata Stimpson. BRACHIOPODA. Glottidia albida Hinds. PELECYPODA. Arca canalis Conrad (M). Arca trilineata Conrad (M). Callista angustifrons Conrad (M) (/?). Cardium meekianum Gabb (M ?). *Cardium meekianum Gabb n. var. A. Chione gnidia Broderip and Sowerby (/). Chione sp. Clidiophora punctata Conrad (/). Corbula sp. Cryptomya californica Conrad (/). *Cryptomya n. sp. A. (aff. californica Conrad). Dosinia ponderosa Gray (/). Dosinia sp. * Leevicardium n. sp. (aff. substriatum Conrad). Leda (cf.) fossa Baird (/?). Leda taphria Dall (/). Macoma calearea Gmelin (/). Macoma inquinata Deshayes (/). Macoma nasuta Conrad (/). Mactra californica Conrad (7). Mactra hemphilli Dall (7). Modiolus rectus Conrad (7). Moerella salmonea 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—continued. Siliqua lucida Conrad (7). Siliqua patula Dixon (7). Spisula catilliformis Conrad (/). Spisula faleata Gould (7). 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 (7). Yoldia scissurata Dall (/). Zirphiea gabbi Tryon (7). GASTEROPODA, Admete gracilior Carpenter (N). Astyris californiana Gaskoin (/). | Astyris gausapata Gould (/). Astyris richthofeni Gabb (N). Bittium asperum Gabb (/). Boreotrophon pacificus Dall (/). *Buccinum n. sp. A. *Calliostoma n. sp. A. Chrysodomus liratus Martyn (/). Chrysodomus tabulatus Baird (/). *Chrysodomus n. sp. A. Crepidula princeps Conrad (M) (N). Crepidula navicelloides Nuttall (/). Crepidula (cf. ) onyx Sowerby (/). Crepidula rugosa Nuttall. *Dolichotoma n. sp. (aff. carpenteriana Gabb). Drillia incisa Carpenter (/). *Pusus n. sp. (aff. ragosus Trask). *Galerus inornatus Gabb. Leptothyra paucicostata Dall (7). | Lunatia lewisii Gould (/). Nassa californiana Conrad (N). Nassa mendica Gould (/). | Nassa perpinguis Hinds (/). Natica clausa Broderip and Sowerby (1). *Neptunea humerosa Gabb. 28 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. List of Purisima formation (lower Pliocene) fossils—Continued. GASTEROPODA—continued. GASTEROPODA—continued. Neverita recluziana Petit (/). Sigaretus debilis Gould (/). Olivella intorta Carpenter (7). | Solariella peramabilis Carpenter (1). Pleurotoma perversa Gabb (/). | Tornatina culcitella Gould (l). Pleurotoma sp. Tritonium sp. Priene oregonensis Redfield (/). | *Voluta n. sp. (?) A. Purpura crispata Chemnitz (/). E Rostellaria indurata Conrad (M). CRUSTACEA. Serpulorbis squamigerus Carpenter (/). 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: List of San Diego formation fossils. [Those marked with an asterisk (*) are supposed to be extinct.] ECHINOIDEA. | PELECYPODA—continued. Echinarachnius excentricus Eschscholtz. Pecten hastatus var. navarchus Dall. Strongylocentrotus purpuratus Stimpson. Pecten healeyi n. sp. Pecten hemphilli Dall. BRACHIOPODA. Pecten opuntia Dall. Pecten stearnsii Dall. Phacoides acutilineatus Conrad. Phacoides nuttalli Conrad (=Lucina id.). Pododesmus macroschisma Deshayes. Leda taphria Dall. | Tapes staminea Conrad. Macoma nasuta Conrad. Mactra (Spisula) catilliformis Conrad. Metis alta Conrad. Laqueus jeffreysi Dall. PELECYPODA. GASTEROPODA, Crepidula princeps Conrad. nan atnia Cl " . 1 G Modiolus rectus ie onrad. Dentalium neohexagonum Sharp and Pilsbry. Ostrea veatchii Gabb. Neyerita recluziana Petit. Pecten ashleyi n. sp. ; Opalia anomala Stearns. Pecten bellilamellatus n. sp. Opalia varicostata Stearns. Pecten cerrosensis Gabb. Purpura crispata Chemnitz. Pecten cooperi n. Sp. Scala stearnsii Dall. Pecten hastatus Sowerby. Seala tineta Carpenter. Pecten hastatus var. hericius Gould. Turritella cooperi Carpenter. MERCED FORMATION. TYPE LOCALITY. The type locality is the sea cliff south of Lake Merced, San Mateo County, Cal. NAME AND DESCRIPTION. 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 seq. bo (Je) PLIOCENE FORMATIONS. DEFINITION, The type section of the Merced formation consists of a series of rather soft, gray sandstones and sandy shales, interbedded with hard pebbly conglomerates, hard well-cemented shell layers, and occasional lignitic seams. The total thick- ness of the formation is approximately 5,000 feet. In age the Merced probably represents the upper Pliocene and lower Pleistocene, although there is no appar- ent unconformity in the type section, which is certainly Pliocene at the base and Pleistocene at the top. LOCALITIES. Mytilus beds, Shoalwater Bay, Oreg. (Dall, 1898, p. 336). Upper portion of the ‘‘ Wildcat formation,’ Eel River, Humboidt County (?). Sea cliffs south of Lake Merced and foothills between them and Twelvemile Creek; north of Pillar Point; uppermost beds in sea cliff at mouth of Aho Nuevo Creek, San Mateo County. Felt Lake, near Stanford University, Santa Clara County. Uppermost beds at Capitola, Santa Cruz County. Beds at Bath House Beach 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, Deadman 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 be borne in mind. Pecten fauna.—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: LP. ashleyi, P. bellus, P. bellilamellatus, P. caurinus, P. cerrosensis, P. coopert, P. (Hinnites) giganteus, P. hastatus and its varieties hericius, hindsii, navarchus, and strategus, P. healeyi, P. hemphitli, P. islandicus, P. jordani, P. latiauritus, P. opuntia, P. parmeleei, P. riversi, and P. steurnsii. The following fauna has been found at or in the immediate vicinity of the type locality of the Merced formation, and may be taken as characteristic of the horizon represented by the whole formation: 30 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. List of Merced formation (upper Pliocene) fossils.@ [Those unmarked haye been reported from the type locality; those followed by (T) have been found only at Twelyemile 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.] ECHINOIDEA. PELECYPODA—continued. Echinarachnius excentricus Eschscholtz. Tresus nuttalli Conrad. ; * Scutella interlineata Stimpson. Venericardia ventricosa Gould. PELECYPODA. GASTEROPODA. *Arca trilineata Conrad. Cardium corbis Martyn. Astyris gausapata Gould. * Cardium meekianum Gabb. *Astyris richthofeni Gabb. Cardium quadrigenarium Conrad (F). Bittium asperum Gabb. Chione succincta Valenciennes. Bittium filosum Gould. Cryptomya californica Conrad. Chrysodomus liratus Martyn. Macoma calcarea Gmelin. Chrysodomus tabulatus Baird. Macoma inquinata Deshayes (T). Crepidula princeps Conrad. Macoma nasuta Conrad. Crepidula navicelloides Nuttall. Macoma (like sabulosa Spngl. ). Drillia incisa Carpenter. Mactra californica Conrad. Drillia inermis Hinds. Modiolus rectus Conrad (T). Litorina planaxis Philippi (S). Mytilus californianus Conrad. Lunatia lewisii Gould. Mytilus edulis Linné. Monoceros engonatum Conrad. Ostrea sp. ? Margarita pupilla Gould (S). Pecten latiauritus Conrad (8). Nassa fossata Gould. Pododesmus macroschisma Deshayes. Nassa mendica Gould. Psephis lordi Baird. Natica clausa Broderip and Sowerby. *Saxidomus gibbosus Gabb. Olivella biplicata Sowerby. Saxidomus gracilis Gould. Olivella intorta Carpenter. Siliqua patula Dixon. Pleurotoma sp. indet. (F). Solen sicarius Gould. Purpura canaliculata Duel. Spisula falcata Gould. Purpura saxicola Valenciennes. * Tapes staleyi Gabb. | *Trochita filosa Gabb. Tapes staminea Conrad. | Turritella sp. In southern California the Merced is represented by a somewhat different fauna from that found at the type locality. The Pliocene of Deadman 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 Deadman Island. [Those marked with an asterisk (*) are believed to be extinct.] ANTHOZOA. PELECYPODA, Caryophyllia californica Vaughan. Chama pellucida Sowerby. Corbula luteola Carpenter. BRACHIOPODA. Ieee ie he. : Cumingia californica Conrad. Laqueus jeffreysi Dall. Kellia laperousii Deshayes. *Terebratalia smithi Arnold. Leda taphria Dall. «Lawson, A. C., 1893, pp. 144-145; 1895, p. 460; also Ashley, G. H., 1895, pp. 332-333. PLEISTOCENE FORMATIONS. 31 List of Pliocene fossils from Deadman Island—Continued. PELECYPODA—continued. GASTEROPODA—continued, Lyonsia californica Conrad. Conus ecalifornicus Hinds. Macoma calcarea Gmelin. Cryptochiton stelleri Middendorf. Macoma inquinata Deshayes. * Drillia merriami Arnold. Marcia subdiaphana Carpenter (Clementia id. ) Drillia torosa Carpenter. Mytilimeria nuttalli Conrad. Fusus barbarensis Trask. Nucula, castrensis Hinds. Hipponyx antiquatus Linné. Panomya ampla Dall. Litorina planaxis (Nuttall) Philippi. Panopea generosa Gould. Mangilia sculpturata Dall. Pecten caurinus Gould. Nassa californiana Conrad. Pecten hastatus Sowerby. Nassa fossata Gould. Pecten hastatus var. hericius Gould. Nassa mendica Gould. Pecten hastatus var. hindsii Carpenter. Nassa mendica var. cooperi Forbes. *Pecten jordani Arnold. Nassa perpinguis Hinds. *Pecten stearnsii Dall. Natica clausa Broderip and Sowerby. Phacoides acutilineatus Conrad. Neverita recluziana Petit. Phacoides californicus Conrad. Ocinebra interfossa Carpenter. Pholadidea penita Conrad. Olivella biplicata Sowerby. Protocardia centifilosa Carpenter. Olivella intorta Carpenter. Solen sicarius Gould. Olivella pedroana Conrad. *Thracia trapezoides Conrad. * Pleurotoma bartschi Arnold. Thyasira gouldii Philippi. * Pleurotoma dalli Arnold. Thyasira bisecta Conrad. Pleurotoma perversa Gabb. Venericardia barbarensis Stearns. * Pleurotoma renaudi Arnold. Venericardia yentricosa Gould. * Pleurotoma smithi Arnold. Venus (Chione) simillima Sowerby. Priene oregonensis Redfield. a ; Puncturella cucullata Gould. SST ROEODAS Puncturella galeata Gould. Acmeea insessa Hinds. Scala indianorum Carpenter. Amphissa corrugata Reeve. Solariella cidaris A. Adams. Bela fidicula Gould. Solariella peramabilis Carpenter. Bittium asperum Gabb. * Taranis strongi Arnold. Calliostoma canaliculatum Martyn. Terebra simplex Carpenter. Calliostoma tricolor Gabb. Thalotia caffea Gabb. Cerithidea californica Haldemann. Tornatina eximia Baird. Chlorostoma brunneum Philippi. Trophon gracilis Perry. Chlorostoma montereyi Kiener. Trophon pacificus Dall. Chrysodomus sp. indet. Trophon stuarti Smith. Chrysodomus rectirostris Carpenter. *Trophon orpheus var. precursor Arnold. Chrysodomus tabulatus Baird. Trophon tenuisculpta Carpenter. Clathurella conradiana Gabb. Turritella cooperi Carpenter. Columbella gausapata Gould. * Turritella jewetti Carpenter. Columbella gausapata var. carinata Hinds. PLEISTOCENE. The marine Pliocene and Pleistocene deposits of California are intimately asso- ciated, 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 County, where 32 TERTIARY AND QUATERNARY PECTENS 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. SAN PEDRO FORMATION. TYPE LOCALITY. The type locality is vicinity of San Pedro, Los Angeles County, Cal. NAME AND DESCRIPTION. This formation was named and described by W. H. Dall, Table of North Ameri- can Tertiary horizons: Eighteenth Ann. Rept. U. 5. 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— separated at all points in the vicinity of the type locality by 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 Pleistocene 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, par- ticularly 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 Holmes, Comox, Vancouver Island, British Columbia (Newcombe). Port Blakeley, near Seattle, Wash., and other localities in the Puget Sound country. Fossil Point, Coos Bay, Oreg. (Dall, 1898, p. 336). Ilwaco, near the mouth of the Columbia River, and Newport, Oreg. (Diller, 1896, p. 479 et seq.) Fort Ross, Humboldt County. Purisima and Punta Afiio 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 Venturaand Summerland, Ventura County. San Pedro, Long Beach, Bells Station, and Los Cerritos Hill, Los Angeles County. Newport, Orange County. Two miles south of Delmar, Pacific Beach, Spanish Bight, and San Diego, San Diego County. a Arnold, Delos and Ralph, The marine Pliocene and Pleistocene stratigraphy of the coast of southern California: Jour. Geol., vol. 10, 1902, p. 124. PLEISTOCENE FORMATIONS. 33 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 fuuna.—Vhe Pecten fauna of the upper, or characteristically Pleistocene, portion of the San Pedro and equivalent formations is as follows: Pecten alashkensis, P. caurinus, P. circularis, and variety xquisulcatus, P. diegensis, P. (Hinnites) giganteus, P. hastatus and varieties hericius, hindsii, navarchus, and strategus, P. tslandicus, P. latiauritus and varieties cerritens/s, delos?, fucicolus and monotimeris, P. subnodosus, and 2. vogdesi. : The following fauna has been found in the upper beds 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) fossils. [Those marked with an asterisk (*) are known so farat San Pedro only from the lower portion of the San Pedro formation. | ANTHOZOA. PELECYPODA—continued. Caryophyllia arnoldi Vaughan. Corbula luteola Carpenter. Caryophyllia pedroensis Vaughan. Cryptomya californica Conrad. Paracyathus pedroensis Vaughan. | Cumingia californica Conrad. r Diplodonta orbella Gould. RE HINOIDEA: Diplodonta serricata Reeve. Echinarachnius excentricus Eschscholtz. ; Donax californica Conrad. Strongylocentrotus franciscanus Agassiz. Donax leevigata Deshayes. Strongylocentrotus purpuratus Stimpson. Glycymeris barbarensis Conrad. ‘ Glycymeris septentrionalis Middendorf. EELECYEODA- *Kellia suborbicularis Montague. Aligena cerritensis Arnold. *Kellia laperousii Deshayes. Amiantis callosa Conrad. *Kennerlia bicarinata Carpenter. Angulus buttoni Dall. *Kennerlia filosa Carpenter. Anomia lampe Gray. Leevicardium substriatum Conrad. Area labiata Sowerby. *Leda fossa Baird. Astarte (Crassinella) branneri Arnold. *Leda hamata Carpenter. * Bornia retifera Dall. *Leda minuta var. precursor Arnold. Callista newcombiana Gabb. Leda taphria Dall. *Callistata subdiaphana Carpenter. *Lima dehiscens Conrad. Cardita (Carditamera) subquadrata Carpenter. | Lithophaga plumula Hanley. (Lazaria id.) Lyonsia californica Conrad. Cardium corbis Martyn. *Macoma calearea Gmelin. Cardium elatum Sowerby. Macoma indentata Carpenter. Cardium procerum Sowerby. Macoma inquinata Deshayes. Cardium quadrigenarium Conrad. Macoma nasuta Conrad. Chama exogyra Conrad. Macoma nasuta yar. kelseyi Dall. Chama pellucida Sowerby. Macoma secta Conrad. Clidiophora punctata Conrad. Macoma yoldiformis Carpenter. * Cooperella subdiaphana Carpenter. Mactra californica Conrad. 17260—No. 47—06 9 oO 34 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. List of San Pedro formation (Pleistocene) fossils—Continued. PELECY PODA—continued. Mactra exoleta Gray. Mactra hemphilli Dall. Metis alta Conrad. Modiolus fornicatus Carpenter. Modiolus rectus Conrad. *Moerella salmonea Carpenter. *Mytilimeria nuttalli Conrad. Mytilus edulis Linné. *Nezera 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. zequisulcatus Carpenter. Pecten hastatus Sowerby. *Pecten hastatus var. hericius Gould. *Pecten hastatus var. strategus Dall. *Pecten jordani Arnold. Pecten latiauritus Conrad. Pecten latiauritus var. cerritensis n. var. *Pecten latiauritus var. delosi n. sp. Pecten latiauritus var. monotimeris Conrad. Pecten subnodosus Sowerby. Pecten yogdesi n. sp. Periploma argentaria Conrad. Petricola carditoides Conrad. Petricola (Petricolaria) cognata C. B. Adams. Petricola denticulata Sowerby. Phacoides (+ Lucina) acutilineatus Conrad. Phacoides (-+Lucina) californicus Conrad. Phacoides (-++-Lucina) tenuisculptus Carpenter. Pholadidea penita Conrad. Platyodon cancellatus Conrad. Pododesmus (Monia) macroschisma Deshayes. *Protocardia centifilosa Carpenter. Psammobia edentula Gabb. *Psephis salmonea Carpenter. Rupellaria lamellifera Conrad. Sanguinolaria nuttalli Conrad. Saxidomus gracilis Gould. Semele decisa Conrad. Semele pulchra Sowerby. *Semele pulchra var. montereyi Arnold. *Septifer bifurcatus Conrad. Siliqua lucida Conrad. Siliqua patula Dixon var. nuttalli Conrad. Solen sicarius Gould. Spisula catilliformis Conrad. Spisula falcata Gould. PELECYPODA—continued. Tagelus californianus Conrad. Tapes lacineata 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 Sowerby. Venus (Chione) gnidia Broderip and Sowerby. Venus (Chione) neglecta Sowerby. Venus (Chione) simillima Sowerby. | Venus (Chione) succincta Valenciennes. *Verticordia novemcostata Adams and Reeve. Yoldia cooperi Gabb. *Yoldia scissurata Dall. Zirphea gabbi Tryon. GASTEROPODA. Acmeea depicta Gould. Acmzea insessa Hinds. Acmiea instabilis Gould. Acmezea mitra Eschscholtz. Acmeea paleacea Gould. Acmza pelta Eschscholtz. Acmeea spectrum (Nuttall) Reeve. Actzeon (Rictaxis) punctoccelata Carpenter. Actzeon traskii Stearns. * Admete gracilior Carpenter. * Amalthea antiquata Linné. (Hipponyx id. ) Amalthea cranioides Carpenter. Amalthea tumens Carpenter. Amphissa corrugata Reeve. * Amphissa ventricosa Arnold. Amphissa versicolor Dall. Bela fidicula Gould. * Bela sanctze-monicee Arnold. Bittium asperum Gabb. * Bittium californicum Dall and Bartsch Bittium filosum Gould. Bittium quadrifilatum Carpenter. Bittium rugatum Carpenter. Bittium williamsoni Arnold. Bulla punctulata A. Adams. Bulla quoyi Gray. *Cadulus fusiformis Sharp and Pilsbry. Ceecum californicum Dall. PLEISTOCENE FORMATIONS. 35 List of San Pedro formation ( Pleistocene) fossils—Continued. GASTEROPODA—continued. Creum crebricinctum Carpenter. * Creecum magnum Stearns. Calliostoma annulatum Martyn. Calliostoma canaliculaturn Martyn. Calliostoma costatum Martyn. Calliostoma gemmulatum Carpenter. Calliostoma tricolor Gabb. Cancellaria cooperi Gabb. Cancellaria crawfordiana Dall. Cancellaria fritonidea Gabb. Cerithidea californica Haldemann. Chlorostoma aureotinctum Forbes. Chlorostoma brunneum Philippi. Chlorostoma funebrale A. Adams. Chlorostoma funebrale var. subapertum Carpenter, Chlorostoma gallina Forbes. Chlorostoma montereyi Kiener. Chlorostoma pulligo Martyn (Phorcus id. ). Chlorostoma (Omphalius) viridulum var. ligula- tum Menke. Chorus belcheri Hinds. Chrysodomus rectirostris Carpenter. * Chrysodomus tabulatus Baird. Clathurella conradiana Gabb. *Columbella (Astyris) californiana Gaskoin. Columbella (&sopus) chrysalloidea Carpenter. Columbella (Astyms) gausapata Gould. Columbella (Astyris) gausapata var. Hinds. Columbella (Anachis) minima Arnold. *Columbella (isopus) oldroydi Arnold. Columbella solidula yar. preecursor Arnold. Columbella (Astyris) tuberosa Carpenter. Conus californicus Hinds. Coralliophila nux Reeve. * Crepidula aculeata Gmelin. Crepidula adunca Sowerby. Crepidula dorsata Broderip. Crepidula princeps Conrad. Crepidula onyx Sowerby. Crepidula rugosa Nuttall. Crucibulum spinosum Sowerby. * Oryptochiton stelleri Middendorf. Cylichna alba Brown. Cypreea spadicea Gray. *Cythara branneri Arnold. Dentalium indianorum Carpenter. Dentalium neohexagonum Sharp and Pilsbry. Dentalium pseudohexagonum Dall. Dentalium semipolitum Broderip and Sowerby. * Diastoma, sp. indet. Drillia cancellata Carpenter. carinata GASTEROPODA—continued. Drillia hemphilli Stearns. Drillia inermis Hinds. Drillia inermis var. penicillata Carpenter. Drillia johnsoni Arnold. * Drillia merriami Arnold. * Drillia montereyensis Stearns. Drillia pudica Hinds. Drillia torosa Carpenter. Srato columbella Menke. * Kulima faleata Carpenter. Eulima hastata Sowerby. Hulima micans Carpenter. | Eupleura muriciformis Broderip. Eupleura muriciformis var. curta Arnold. Fissuridea aspera Eschscholtz. Fissuridea inzequalis Sowerby. Fissuridea murina (Carpenter) Dall. Fissurella voleano Reeve. Fusus barbarensis Trask. Fusus luteopictus Dall. Fusus robustus Trask. * Fusus rugosus Trask (=F. arnoldi Cossmann). Gadinia reticulata Sowerby. Galerus mammillaris Broderip. Haliotis fulgens Philippi. Haminea virescens Sowerby. Helix (Epiphragmophora) sp. indet. Isapis fenestrata Carpenter. Ischnochiton regularis Carpenter. *Tvara turricula (Carpenter) Dall and Bartsch. Lacuna compacta Carpenter. Lacuna porrecta Carpenter. Lacuna solidula (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. pedroana Arnold. Mangilia interlirata Stearns. * Mangilia oldroydi Arnold. * Mangilia painei Arnold. * Mangilia sculpturata Dall. Mangilia striosa C. B. Adams. Margarita optabilis var. kneehti Arnold. 36 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. List of San Pedro formation (Pleistocene) fossils—Continued. GASTEROPODA—continued. * Margarita optabilis var. nodosus Arnold. Margarita parcipicta var. pedroana Arnold. Marginella jewettii Carpenter. Megatebennus bimaculatus Dall. Mitra maura Swainson. * Mitramorpha filosa Carpenter. *Mitramorpha intermedia Arnold. Monoceros engonatum Conrad. Monoceros lapilloides Conrad. Mopalia ciliata Sowerby. Murex (Pteronotus) festivus Hinds. Murex (Pterohytis) foliatus Martyn. Murex (Pterohytis) nuttalli Conrad. Murex (Chicoreus) leeanus Dall. Murex (Cerostoma) monoceros Sowerby. Murex trialatus Sowerby. Nassa californiana Conrad. Nassa cerritensis Arnold. Nassa fossata Gould. Nassa insculpta Carpenter. Nassa mendica Gould. Nassa mendica var. cooperi Forbes. Nassa perpinguis Hinds. Nassa tegula Reeve. Nassa versicolor yar. 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 keepi Arnold. Ocinebra lurida Middendort. Ocinebra lurida var. aspera Baird. Ocinebra lurida var. cancellina Philippi. Ocinebra lurida var. cerritensis Arnold. *Ocinebra lurida yar. munda Carpenter. Ocinebra micheli Ford. 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 borealis Gould. Opalia crenitoides var. insculpta Carpenter. Pachypoma inzequale Martyn. Paludestrina curta Arnold. Paludestrina stokesi Arnold. GASTEROPODA—continued. Phasianella compta Gould. *Physa heterostropha Say. Pisania fortis Carpenter. Planorbis tumidus Pfeiffer. Planorbis vermicularis Gould. Pleurotoma (Borsonia) bartschi Arnold. Pleurotoma (Dolichotoma) carpenteriana Gabb. Pleurotoma (Dolichotoma) cooperi Arnold. *Pleurotoma (Borsonia) dalli Arnold. *Pleurotoma (Borsonia) hooveri Arnold. *Pleurotoma (Leucosyrinx) pedroana Arnold. Pleurotoma perversa Gabb. *Pleurotoma (Drillia) renaudi Arnold. *Pleurotoma (Spirotropsis) smithi Arnold. Pleurotoma (Dolichotoma) tryoniana Gabb. Pomaulax undosus Wood, Priene oregonensis Redfield. Puncturella cucullata Gould. *Puncturella galeata Gould. Purpura crispata Chemnitz. Purpura saxicola Valenciennes. Pyramidella conica var. variegata Carpenter. Ranella californica Hinds. Rissoa acutelirata Carpenter. Seala bellastriata Carpenter. Scala crebricostata Carpenter. Scala hemphilli Dall. Scala hindsii Carpenter. Scala indianorum Carpenter. Scala tincta Carpenter. *Seila assimilata C. B. Adams. Serpulorbis squamigerus Carpenter. Sigaretus debilis Gould. Siphonalia kellettii Forbes. | Spiroglyphus lituella Morch. *Styliferina tenuisculpta Carpenter. Taranis strongi Arnold. Terebra (Acus) simplex Carpenter. * Thalotia eaffea Gabb. Tornatina cerealis Gould. Tornatina eulcitella Gould. Tornatina harpa Dall. | Triforis adversa Montague. Trivia californica Gray. Trivia solandri Gray. Tritonium gibbosus Broderip. Trophon (Boreotrophon) cerritensis Arnold. *Trophon (Boreotrophon) gracilis Perry. Trophon (Boreotrophon) multicostatus Eseh- scholtz. *Trophon orpheus var. precursor Arnold. Trophon (Boreotrophon) pedroanus Arnold. GEOLOGIC RANGE OF CALIFORNIA PECTENS. mill List of San Pedro formation (Pleistocene) sossilsa—Continued. GASTEROPODA—continued. GASTEROPODA—continued. Trophon (Boreotrophon) pacificus Dall. Turbonilla subcuspidata Carpenter. * Trophon stuarti Smith. Turbonilla tenuicula Gould. * Trophon ( Boreotrophon) triangulatus Carpenter. | * Turbonilla torquata Gould. * Turbonilla adleri Dall & Bartsch. *Turbonilla torquata var. stylina Carpenter. *Turbonilla arnoldi Dall & Bartsch. Turbonilla tridentata Carpenter. Turbonilla aurantia Carpenter. Turritella cooperi Carpenter. Turbonilla crebrifilata Carpenter. Turritella jewetti Carpenter. * Turbonilla gibbosa Carpenter. * Vermicularia, sp. indet. Turbonilla laminata Carpenter. Vitrinella williamsoni Dall. Turhonilla latifundia Dall & Bartsch. Volvarina varia Sowerby. Turbonilla lowei Dall & Bartsch. * Volvula cylindrica Carpenter. Turbonilla muricata Gould. * Turbonilla pentalopha Dall & Bartsch. BSCE Ee. Turbonilla similimis Cc. B. Adams. Urolophus halleri Cooper(?) Turbonilla stearnsii Dall & Bartsch. GEOLOGIC RANGE OF CALIFORNIA PECTENS. Range of species and varieties. [? shows limits somewhere between which the species belongs. ] ‘Recent. prelate Pliocene. Miocene. Cue Eocene. haere. | | : , | i San | Mer- Purisi-| San | Monte-) Vaque-/San Lo-| 7», Marti- i ee RA oo EE RE era Se Pecten: | | | | | | | | | ‘alaskensisal)allesseaee se ee a= Tare Inn joseece eo SS aOR Sena ls cseneess ere ea (Scar, al iets iE and erscnimaspeseeeeee aes os sae ee [Keser [peeved leaner Titirloatatatatie eatitatatia| var. barkerianus n. var | | ttt | neileyal mY Ege cccosessoceesalasssoclscacea|| IM. || 1NMh poses Soeeecllossson EMEA AIN, (0) .-oessscsocsecesoasa4leusiacslscocea|| IMM! |lbceoaclcesuclleceoselbarccd|esoscs|=codee SGC I DO addgconcsteabelecndasliecaces|éosseql) IT Gosebs| besecs|beaods| Sacescioacesolecaccc alls Cane Cle posed seososolesssed beeess |] SHIM A eeecaslssdatallaseced| esepoel seers lbsosae bellilamellatus!nsispo-- sec -4|---—.-|s—s5—5 Bee eas ios vers amie | ieetesel| Sarees bowersinsp---55---2------- Ye ae pp ety | vd eral | mae ee rca pratacarial loot tiiitind liccers eiovas| arate eal eee branneniin.spen seca aa | SES Lag eee ny eat ee lemseme|aaccee|~ cscs Thitaeeditio, leceee ee ee CALKIN SIO MNS pleases sees ee | sere a ecicies lester eSace [RSE S eae 27 N oBcoalbcasee fit t\see es Carnizoenslanespaa- see ee eet ace oe [seca ase ciee «lect ool jarerorpal eearenerg a Mesretarel een meso eel omc CauTINusiGouldssesess- see sratat taal dstatctatea leapt tie statisti Teale oe | Sees lo seelac ecw oe 4am bene CELOSENSIn Gab Dees eeeseee sees Poo state liectitatitied eer cis = Sees leis © sero ere onic Claes var. mendenhalli n. var-.|.-..-. |aecoa acaaas peeece TUCMe Ae ea tedl RaaBeS Sa Qoe SeceaS circularis Sowerby...-.------ +ttt | THAN deed Ree aca Aclldseceelleeoose | Pee laird Kiana © var. zequisulcatus Cpr----) {{ff | Tit |------|------|------|------ | Soe eee |-Sragee \aaieael aaa Clallamensismes press aeseee teeter eemeenleecene ees LR = le |e SRA Hie, Mel Seen becaae a ; | coalingaensis n. sp..-.-.-.---|------ Ie Rice lease SAAT r ol eeeeel ea eee MBeee retell eae nl eect COOPER MN! Spanos sosecceescs|soss-|sscsce| tnealatititiniglesosice|Sesces esas peeara acces sansos coosensis Shumard | tttt TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA, Range of species and varieties—Continued. Ge OF 8E [? shows limits somewhere between which the species belongs. ] Iecertl See Pliocene. Miocere. ORES Eocene. | living St, | Mer |Puri| Sen, |Monte-|Vauue en 10" rejon,| Matt eee Wes eee a © 5 id eee | Co Pecten—Continued. | crassicardo Conrad ees saree ences | eet een IOMAL WAGE WG eeseos eocencaissese Lees lake Ths WO anole Saleen acellose seAlloacosc TALE] a) Pel SR LA at Reh 05 el eevee pine ee davidson) Dalle eesnstesee TER os eo eC cere | See merrell Seen care Rese eres eran ese desertii@onradia=ass= scorer eis Bfie ee Aalles eee oss 22h UPR Pagae: | Mpuesy: Cal Nays ea i pee | y= oe diecensisyDalla= see ee +ttt AFA Gace es sean eet os becaccllacocon Wes cn ie ore eee po bUBKevertel D Faull Se Ge = ba Us per ae aM eee aos Sy Ree Peto ll ele tates, averarote|| eketmeare i] Sosa state eveyeeeas| remem GIscustSonradhee rma mee Sales 2 all eevee | een | eee HRD Ral Each ll laos acess losers lasoans eldndpeimaspieeereeeerocccelgeeent [A A ese as IM oseeosfsseese | TR bts AIT es Seth estrellanus|@onrad 222-.- -_.-|5...-- ean sean lssaod tttt tetas eatatatati | SSeS tone odl sass VEly Guibilingans Whe SAaeeboe oo) [Raeeee, 0 ae hese TRON @ Wace al Secs eee ee Cee NEM Ley do oNb OUI} Toe \t2) Soest sete Heer ats Soa=at| see coe harhifititic jesse soe ae erence 4 MS Spel I eee 7 excavatus Antoni----.-.---.- IHG Ie Geecee Geese esos soscco Saesee aeeees Sonora Koes sooce fucanus)Dalivereees see eases ase e leopeeees eel eet 2222 | Pee? Rie eee ee bose rel eosee giganteus! Grave eee a2 21 tttt lacaap nite (ana | Gahtp lane | GaRAP beee=sleeease|-cc2- hamlliniin as ppereeee ee se —| sone s Se eee cee aC RI AT aid lin ek Bay re IGE Oe OF Keeeretee eae Pee es be cress hastatus Sowerby ........--. thtt | sitittal stista titty |e sael See oes eee iaee =] See eeeteee VarvalbidusiDall meavarlellditit jass2=slassess|==2see epee ad eer Jaseeec|eccetene bteoas) senade var. hericius Gould... ..-.- tatatite nl” tatatite atalalatin | aatihitatint| Malitimaeel| sees ee TE 8 |S ee ee |b var. hindsii Carpenter...) +++ | IMUM MATA PNRIM WML Sees bocceeoapeiad SaseK4 Sosess oaeese var. navarchus Dall ...-.. | ttt | tttt | Witten loeaseos PP a | [eee Fs era oe ea Pp Be var. strategus Dall. -.._--- ttt stitatatiee | enititalithe aati an eee [See em | tla: Stereo ees hneale vines pasemeemes seme Nest hie | ct ey ees ee ttt Peers | bas |peeees Besens secass psoas hemphillig alll seeee esas s|a52 sso oes Tite | etatatah | Part ee ee eee ceee interradiatuatGabbreensssesel nee |e eeeelaeseoe tenn [eae || eae A = 2 eee Tiitifaleeeoee islandicus Muller...........- LAMA CRRIRITE ll seeeee GSsess sakes see olsao sacle sees TOMEI, ANAL. WA CoScaodaeelleee eee bene] | SHARING 0 llecostn pocaca|leancas sees Geen Beere Recpimn tshirt load Roemer (toe Me raral eraraa lore tcawi hee ou... land esilin. Spl assaee ase s= ec accceslseee lease nal ace ae ioc tocis| wae Somes sScinse lilinifel eeosae latiauritus'Conrad.......-2_- Tht te | Sttttal ties ||Beeecslessescl assess eee ee Jecoacs|esaess var. cerritensis n. var...-|....-.| +ttt | Bae ee sore | oa hese . oe a ee {Bob opel eens var. delosi n. var.....--- tatatae lt tatitito| ese ce | eeeae aces |oceoec|[seocsc/eancsd|sccosnleonone var. fucicolus Dall.....-- aneine. || Wink | sofa aes Eee ety | ects [ashe [toe Pees Sececee[eeee ee eee var. monotimeris Con soul) WMA | MG hel oeacellaaeeu haces | Bees eee | bres Sina Mecreaie| Seneiee lawson my Sp)ssscee- see peaewall ens £8 |n---=- Poo ate tetis | eee | See ll eee eee ener lecontelinn space seeee eee ale eea sa |2= sens oe cee seer areas 66 Pa (Chiamys) ihamilinims sp sssesseseneace secre. soca es se oer e eee 67 Ps (Chiamiys))hastatusivar-bericius!Goulde-- =. .-22-5- -=-9-eeeeeee ee 110 P. (Chlamys) nutteri n. sp .--.------ BEE n SEE Oca ae beemieten Ssack 67 Pa (Chiamtys)isespeensisims pees = -- s-os- 25 eee ace ce con soaeeee ens 69 P-7(Chiamys)|isespeensis var. hydeiln. var-.-.---.----+-----------=- 69 aThe 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. 41 42 TERTIARY AND QUATERNARY PECTENS OF Class PELEGYPODA—Continued. Order PRIONODESMACEA Superfamily PECT Family Prcrin Genus Pec Mioce lee iE: Continued. INACEA—Continnued. Ip.&—Continued. ten Muller—Continued. ne Pectens—Continued. CALIFORNIA. (ynopecten)bowersiasisp)-2 se seaer eee teen ee nee een eee (Lyropecten) crassicardo Conrad . (Lyropecten) crassicardo var. ua (uyropecten))estrellanus! Conrad fea=s-==ee-e ce este eee eee = see . (Lyropecten) estrellanus var. . (Lyropecten) estrellanus var. . (Lyropecten) magnolia Conrad . (Lyropecten) miguelensis n. sp . (Lyropecten) perrini n. sp -- . (Lyropecten) vaughani n. sp . (Plagioetenium) andersoni n. . (Plagioctenium) andersoni var. barkerianus n. sp . (Plagioctenium) cerrosensis var. mendenhalli n. var . (Plagioctenium) deserti Conrad . (Plagioctenium) discus Conrad . (Plagioctenium ) eldridgei n. . (Plagioctenium) neahensis n. . (Plagioctenium) pabloensis Conrad catalinge neavanses. see terminusine Wane eee sp BDricu cence see remeeer SPSakHe-ec msec eee eee ee hamiltoni¢ns yar=-so-- soe P. (Pseudamusium)) lompicoensis ny speave.s25s2+5-2e2 ss eee eee iP (Eseudamusium) | pedroamusulrasks seat oe see pee See see eee P. (Pseudamusium) peckhami Gabb (persists from Oligocene) .------ P. (Propeamusium) clallamensis n. sp. (persists from Oligocene). .- ~~ P:)\(Propeamusium))stanfordensism. spices sssecit=- =o eeseeeesee ae eee P. (Propeamusium) wavlandi n. sp. (persists from Oligocene) --.---- P((Amueium))) lompocensis m.spsesesere= oneness ee eee Ps\(Hinnites) (giganteus; Grays cscer sateen ee ere nee eee aaa Pliocene Pectens.-< 2..iicgsceiin a6 we puso cem bein oe tee oe sao nee anemeee Pe (Pecten\) auburyiinisp ve eeeceeee cenit eee ena eae eec eee Pe PR: D> Law} (Pecten) bellus Conrad ~~ _-- (Recten)) (coalingaensisinaaph seer oe eee eee eee ee eee . (Pecten:));/hemphilli Dall 262 oe ae see sae eee orc eee eae w(recten’):lecontel neisp esse ae meneas aeeseeeae eee eee sees 3 (Becten)merriamimspr see aeeee ey oleae ses eererimes eee / \(Pecten)! atearnsit Dall’ Ssae-ee emer eee eee See . (Pecten))! vogdesiany spies cae) jac eaynae ue eae eee ee . (Patinopecten) caurinus Gould . (Patinopecten) dilleri Dall (persists from the Miocene ?) . (Patinopecten) healeyi n. sp . (Patinopecten) oweni n. sp. (persists trom Miocene) . (Patinopecten) purisimaensis n. sp . (Patinopecten) turneri n. sp . (Nodipecten) veatchii Gabb 7 (Chiamiys)sbartsehijmeispreesseeemese see eee eee eee aes - (Chlamys) bellilamellatus n. . (Chlamys) hastatus Sowerby RID cclesaseuasgacesscscnssc . (Chlamys) hastatus var. hericius Gould (persists from Miocene) - - - . (Chlamys) hastatus var. hindsii Carpenter . (Chlamys) hastatus var. navarchus Dall . (Chlamys) hastatus var. strategus Dall . (Chlamys) islandicus Miller SYNOPSIS OF SUBGENERA AND SPECIES, Class PELEGYPODA—Continued. Order PRIONODESMACEA—Continued. Superfamily PECTIN ACEA—Continued. Family Prcrinip#—Continued. Genus Pecten. Miiller—Continued. Pliocene Pectens—Continued. P. (Chlamys) jordani Arnold ....---------------------------2777--> P. (Chlamys) latiauritus (hie = Sa daeee OB AResadeeereeesceane sce P) ((Chlamys)) Jawsoni i. sp----------2-----=-=--*-------22 25-22-55 P. (Chlamys) nutteri n. sp. (persists from INMGERYS | ao ase cceeobesons P. (Chlamys) opuntia Dall .-.--..--------------------------------- P. (Chlamys) parmeleei Dall ---.-------------------------+--7----- P. (Chlamys) washburnei n. sp .---------------------------++7----- P! (@hlamiys)) wattstm. Spie- <= s--—-= === =- 2 === = i P. (Chlamys) wattsi var. morani n. var. ---------------------------- P. (Lyropecten) ashleyi n. sp.------------------+--------522777077- P. (Lyropecten) estrellanus var. eatalinze n. var. (persists from INMGIRENEO)) HaASnocees cee SaSbocee ates nc come See Crnr Ses nooo a Jaee ac P. (Plagioctenium) cerrosensis Gabb -.----------------------------- P. (Plagioctenium ) circularis Sowerby (?) -------------------------- P. (Plagioctenium) cooperi n. sp ------------ Bes sae sei =clee =e P. (Pseudamusium) pedroanus Trask (persists from Miocene)....---- P. (Propeamusium) riversi n. sp -----------------------+272---7---- P. (Hinnites) giganteus Gray (persists from Miocene) --------------- Pleistocene Pectens .-..--=--+------+---os2==--=--== =~ == » (@Becten)) diegensie!Dall= 2 = . (Patinopecten) caurinus Gould (persists from Pliocene) ---------- . (Nodipecten) subnodosus Sowerby (persists from Pleistocene) - -- - . (Chlamys) hastatus Sowerby (persists from Pliocene) ----------=- . (Chlamys) hastatus var. albidus Dall'n: var----.----------------- . (Chlamys) hastatus var. hericius Gould (persists from Miocene) - - . (Chlamys) hastatus var. hindsii Carpenter (persists from Pliocene) - . (Chlamys) hastatus yar. navarchus Dall (persists from Pliocene) - - . (Chlamys) hastatus var. strategus Dall (persists from Pliocene) - - -- DH WWW mim twH Fg Fg) Fook Fo 43 44 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA, Class PELECY PODA—Continued. Order PRIONODESMA CE A—Continued. Superfamily PECTINACEA—Continued. Family Prcrryipa—Continued. Genus Pecten Miller—Continued. Recent Peetens—Continued. P. (Chlamys) islandicus Miller (persists from Pliocene) - ------------ P. (Chlamys) latiauritus Conrad (persists from Pliocene) ...-...----- P. (Chlamys) latiauritus var. delosi n. var. (persists from Pleistocene) - P. (Chlamys) latiauritus var. fucicolus Dall (persists from Pleistocene) - P. (Chlamys) latiauritus var. monotimeris Conrad (persists from Pleistocene)),o= a2 actos ae See we rs eee ee soaeise sess ne a= ene P. (quipecten) palmeri Dall...---.------- Ce ys, sake see ae eS P: (Plagioctenium!)) paucicostatus|\Carnpenter®--=-°22--------.----4--- P. (Plagioctenium) circularis Sowerby (persists from Pliocene) ------ P. (Plagioctenium) circularis var. eequisuleatus Carpenter (persists from Pleistocene) ae sc ose see on aa eee cee ee Wane Cee arene Ps (Pseudamusium)) davidson) all peer eee eee eee Ps (Pseudamusium)) randolphisDalliseeees-eeeeeeee eee see sees P. (Pseudamusium) randolphi var. tillamookensis n. var ....-------- P. (Pseudamusium ) vancouverensis Whiteaves..........------------ P. (Propeamusium) alaskensis Dall (persists from Pleistocene) ------- P. (Hinnites) giganteus Gray (persists from Miocene)....--.-------- Umnidentifiable Pectens <3.-32.2 222254 52ececwacece sos -cenceeae sas eseae Pcatillifonmis:Conradd(Miocene) pose eseeonetee aes oe eee eee Ponevadanus*Conrads (Miocene) ames sees eeeeeee ea eeeeeee eerie BP. py xidatus; (Recent). ja2.4. 32.8 estes Salers seen ieee see Paisubcrenatus;Canpentern|((Recent) bee -eee ase eer eee nee e eae patownse ndisGoul da (Recent) esr eee ae arate tee ee ee eee Summary of the subgenera and species. Num bertofisubgenerairepresentedie ae recone ee ee a eee iets Nimmiberrolspeciesinepresented ae mteys cere = lee meet else eters ease et aa eral eee te Oldispeciesimesee tea a cite ccm cleo ai EE ate pA aa eT eer 36 ING WasPe CIES yee sioe ecco sate 3.2 Alciare/etcicis ees Se Se eee ee ele ieee io aete a oerseeeee 40 Numberrolivanietiesirepresen ted sc mrj< <== =/eersen ee ese ee ee ee ee at eee eer eine Oldavarleties® paneer eee s sessed = Sas ae BERR CER EEO Nee Samer oeee acre ae siaey= 7 ING WEWaDlelies meme me ate oc Sais Se oases eS eer ei aters eee ent arse eee ete 10 Numibernonspeciesmnclud edmmybecten: a. Seem em eeteeese eeteeasaie ea aeecee NumbenotepeciesncludedbinePatnopectenee ean rose ee en nes eee eee eee ee eee nes NumberopepeciesincludedmnmNodipecte meee eye mee ieee eee eee eer Numberotspecies an clucedirrx@ bil suri cy apace eat ea tease NumbenotvarietiestineludediiniChlamys==- ss s— eee eee eee a eee eer Number ofispeciesancluded imi lyropecten| ==) s2e- see ee ae eee eee eee een Number of varieties included in Lyropecten.-.----..---- PE Spt Mp te Nye Miter AEE eee este aeons Nunoberofspecteshimelmd ed iimieAiq ui ec te rae aerate ea a ate oe eo Nimniber.ofspeciespme lid ediimeblagiocten Turn yey eee eet ete telel te toetatete al ert eee tare Numberotivanetiesineludedeinvelagiocteniuma jas sree tetera alate ete teree elere Numbexofspeciestincluded ime Psevd armistice ental are arate alata eats ete eee re Numberofivarietiesuneluded ims Ese cl ara scree eee ee ee ee areata tere Number of epeciesmuelid edi tmeAtn tsar epee tea pee ee eat ee Number ofispeciesiincludedtnebro peau Sim as | a= eee entree WAR ROE Coos Numberlotjspectes mel nd ecu rrp bin abe ee epee eel ea SYNOPSIS AND DESCRIPTIONS OF SUBGENERA AND SPECIES. 45 DESCRIPTIONS OF SUBGENERA AND SPECIES. Class PELECY PODA. Order PRIONODESMACEA. Superfamily PECTINACEA. Family Pectinip®. Genus Pecten © Muller. 1776. Pecten (Klein, 1753) Muller, Prodr. Zool. Dan., p. 248. 1778. Pecten Da Costa, Brit. Conch., p. 140. 1798. Pecten Bolten, Mus. Bolt., p. 165. 1799. Pecten Lamarck, Prodr. d’un Nouy. Class. Coq., p. 88. 1898. Pecten Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, p. 689. Type, Ostrea maxima Linné. GENUS PECTEN MULLER. “The shell of /%cten comprises two generally more or less discrepant valves, united along a long, straight hinge line by an inconspicuous ligament and a central strong resilium. A single rounded adductor leaves its impression pretty a 7 SIRT EAN Fic. 1.—Pecten circularis Sowerby var. xquisulcatus Carpenter. Right valve, i. e., the valve having the byssal notch; exterior. Dimensions: ‘‘Altitude’’ is distance between the base (B) and the apex of the shell or umbo (U); *longitude”’ is the distance between the anterior extremity (A) and the posterior extremity (P); ‘‘diameter’’ is the maximum perpendicular distance from the plane of the periphery (margin or border) to the top of the arched disk, when the shell is lying interior downward; A, anterior end; P, posterior end; B, base; U, umbo; U P B A, disk; ae, anterior ear or auricle; pe, posterior ear or auricle; bn, byssal notch or sinus; ba, byssal area; ps, posterior sinus; sm, submargins or lateral areas; r, ribs; 7s, 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 subgeneric classification and descriptions, and also the general discussion relating to Pecten, are taken from Doctor Dall’s monograph of the genusin ‘‘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 yerbatim. Unless otherwise stated, all passages occurring in quotations have been copied from the aboye monograph. 46 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. umbonal region. These pits may be shallow or deep: their basal margin sometimes projects slightly into the cavity of the valves; their apex is always nearly coincident with the umbonal point of the valve. In a few species in the right valve the lateral margins of the pit are raised into tooth-like processes, which fit into corresponding depressions in the opposite valve (e. g., P. swiftii Bernh.), but these are not homologous with the so-called teeth of Piicatula and Spondylus. Outside of these, radiating fanlike from the apex of the valve, are frequently found one to three pairs of more or less prominent laminz, 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 heavy shells, especially such as Pecten proper and Lyropecten, and serve to adjust the closing of the valves, as does the hinge armature of the Teleodonts. In a few species the crura are Fic. 2.—Same species as fig. 1. Right valve; interior. A, P, B and U as in fig. 1; A, hinge line; rp, resilial pit; pp, provinculum; ce, ec, cardinal crura; bn, byssal noteh; em, etenolium; as, adductor sear. sufficiently prominent to actually interlock with the valves half open; in many 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 species the provinculum is evanescent or represented in the adult only by faint vertical strie, which cross the cardinal crura. In a few small, thin-shelled, mostly deep-water species the provinculum is persistent and functional (e. g., P. thalassinum Dall), forming an interlocking hinge. In Pecten proper, Chlamys, 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 grooye between the upper margins of the valves, as in ?. swiftii. The disk of the valve is usually rounded or oblique below and at the sides, GENUS PECTEN MULLER. 47 but 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., 72. /atiauritus Conr.) may exhibit varieties some of which have a well-developed posterior sinus while others are without it. The right anterior sinus is usually emphasized by a flexuosity in the lower edge of the ear above it for the accommodation of the byssus, 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 byssus 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, much like the inequalities of growth shown by the margin of the aperture and the internal lire of some Gasteropods. This set of spines, resembling a short comb with curved teeth, has been called ctenolium, pectineum, and pectinidium. Tn old very heavy shells, which are held in place more by their own weight than by the formation of a byssus, 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 lire to still further strengthen the disk. In addition to the ribs and riblets, the surface of Pecten may be ornamented by fine, almost microscopic groovings, which radiate from the umbo (shown in /. peckhamz), 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 CAlamys, a checkered squamation cr 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-defined.” These characteristics have been altered in the subsequent forms to meet conditions of environment, in some instances certain features appearing and then becoming obsolete as their usefulness decreased. “The discrepancy in size of the yalves 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. excavatus 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. bowers and P. anderson, 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 48 TERTIARY AND QUATERNARY PEOCTENS OF CALIFORNIA. sedentary forms. The movement, although quite rapid, is jerky, and is produced by the expulsion of water through the cavity of the auricles; the ventral margins of the valves being in advance as the animal moves. ‘Tn various geological horizons, as well as in the existing fauna, certain species ot Pecten assume a sessile habit, involving an irregular subsequent growth of the valves after attachment to other objects, as in //innites. These species have no nec- essary genetic connection with one another except what they gain from their rela- tions to the Pectinzde as a group, and must be regarded as purely sporadic adjust- ments of individual forms to a particular environment.” ‘The influence of the environment is very marked among the Pectens. As in mammals and birds, the same species in the northern part of its range is larger than in the south, unless it is a distinctively tropical species. But in color the rule is reversed, the southern species being lighter and more brightly tinted than the north- ern 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, haye more conspicuous concentric sculpture and more solid shells.” The Pectens seem to form a natural genus which may be separated for con- venience into groups, but as might be expected when the fossil forms are taken into consideration, these groups merge into one another by insensible gradations. Whatever might be advisable were our knowledge of the Pect/nédx contined to the recent species, any paleontological division of them can not ignore the inter- gradation which is so obvious between the different types of which the extremes appear so unlike. The subdivisions adopted here, although more or less widely separated in the California fauna, are known elsewhere to be connected by intimate gradations. For that reason they are assigned to a rank compatible with such relations. As would be expected, the relative importance attached to the characteristics upon which groups are founded is regulated more or less by the personal equation; therefore, in order to avoid the complications often arising from a too close discrimination, it has been deemed advisable in this paper to make all of the subdivisions which are worthy of a group name bear the grade of subgenus. The following groups of /ecten are represented in the Tertiary and living fauna of California: Subgenus Pecten s. s. Miiller. . Type P. maximus Linné. tight valve moderately inflated, left valve flattish; sculpture of strong ribs with radial striation, more or less roughened by simple concentric lamellation or incremental sculpture; ears subequal. This group includes the following Pectens: auburyi, bellus, carrizoensis, coalingaensis, diegensis, cacavatus, hemphilli, keepi, lecontei, merriami, sancte- cruzensis, stearnsii, and vogdesi. Subgenus Patinopecten Dall, 1898. Type P. caurinus Gould. Valves with small ribs, flat on the right valve, and sometimes dichotomous; GENUS PECTEN MULLER. 49 smaller and more rounded on the left valve; concentric sculpture inconspicuous; radial striz absent or obsolete, ears subequal;-valyes nearly equilateral. To this group belong the following Pectens: coos: nsis, caurinus, dilleri, healeyi, oweni, purisimde nsis, propatulus, and furnerz. Subgenus Nodipecten Dall, 1898. Type P. nodosus Linné. Shell like Zyropecten, but the ribs intermittently nodose, with more or less prominent hollow nodes or bulla; radial striation pronounced; ears unequal, the posterior smaller, the valves often more or less oblique; imbricate surface layer sometimes very marked. (P. watts’ is a connecting link between this subgenus and the typical Chlamys.) The only representatives of this group are 7. subnodosus and P. veatchii. Subgenus Chlamys Bolten, 1798. Type P. islandicus Miller. Valves moderately inflated, subequal, similar, oblique, or with unequal ears, the posterior smaller; Camptonectes striation and imbricate surface layer usually present; shell usually solid and opaque; byssal notch and ctenolium present. Under this subgenus are grouped the following Pectens: bartschi, bellilaimel- latus, branneri, calkinsi, fucanus, hamlini, hastatus and vars. hericius, albidus, hindsii, navarchus and strategus, islandicus, jordani, landes’, latiauritus and vars. cerritensis, delosi, fucicolus and monotimeris, lawsoni, nutter?, opuntia, parmelee?, proavus, sespeensis, and its variety hyde?, washburnei, watts:, and its variety morani. Subgenus Lyropecten Conrad, 1862. Type P. estrellanus Conrad. Shell resembling /cten s. s., but with both valves convex; usually of large size, heavy, and with radial striation and minute concentric imbrication; ribs entire, and not dichotomous; valves equilateral and sometimes more or less undulated in the vicinity of the umbones. This group includes the following Pectens: Ashleyi, bowers, crassicardo and its variety hamiltond, estrellanus and its varieties cataline and terminus, magnolia, miguelensis, perrini, and vaughani. Subgenus 2quipecten Fischer, 1887. Type P. opercularis Linné. Shell thin, orbicular, with subequal inflated valves, usually equilateral, with uniform, well-marked radial, not dichotomous, ribs and finely imbricate radial striation; ears subequal; valves internally lirate on the edges of the grooves corresponding to the external ribs; Camptonectes striation present, but usually obscured by the radial sculpture; ctenolium and byssal notch obvious. The single representative of this group is 2. palmerv. 17260—No. 47—06 4 50 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. Subgenus Plagioctenium Dall, 1898. Type P. circularis Sowerby. Resembling .2yu/pecten but without radial striation; the concentric sculpture in looped lamelle; the ribs strong, frequently smooth above; the submargins impressed below the subequal auricles; the valves well inflated with a tendency to oblique growth in the adult. This group includes the following species of Pecten: Anderson’, andersoni var. barkerdanus, cerrosensis and its variety mendenhalli, cirewlaris and its variety aequisulcatus, coopert, Aiscus, deserti, eldridget, neahensis, pabloensis, paucicostatus. Subgenus Pseudamusium H. and A. Adams, 1858. Type P. exoticus Chemnitz = P. pseudamusium (Klein) Sowerby. Shells small, thin, more or less translucent; inner face of the disk without: lire; sculpture discrepant on the two valves, the right valve having the concentric and the left valve the radial elements most pronounced; valves usually flattish or compressed. The following Pectens are placed in this group: Dawidson7, lonupicoensis, peck- hami, pedroanus, randolphi and its variety t//lamookensis, and vancouverensis. Subgenus Amusium Bolten, 1798. Type P. plewronectes Linné. Valves flattish, internally lirate, externally usually smooth or faintly striated, both valves being similarly sculptured; the ctenolium absent and the byssal notch obsolete. This group is represented by the single species 7. /ompocensis. Subgenus Propeamusium Gregorio, 1883. Type P. inequisculptus Tiberi (=P. fenestratus Forbes). Right valve impressed about the distal margin, which is not fully calcified, partially coneave, the sides partially closed away from the ears; the internal lire 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: A/lashkens¢s, clallamensis, interradiatus, riversi, stanfordensis, and wayland?. Subgenus Hinnites Defrance, 1821. Type H. cortezi Detrance. Shell (up to advanced youth) a typical Ch/amys, later becoming sessile and irregular, in which stage the resilial pit is elongated and cardinal margin develops an obscure area. This group is represented by the single species Pecten giganteus. DESCRIPTIONS OF SUBGENERA AND SPECIES. onl EOCENE PECTENS. (Those known first to appear in the Eocene formations.] PrcTEN (CHLAMYS) CALKINSI n. sp. Pl. I, figs. 1 and 2. Description.—Shell averaging about 35 millimeters in altitude, subcircular, equivalve or nearly so, equilateral, rather thin, somewhat ventricose, and with only slightly serrate margins. Right valve with the exterior surface ornamented by about 55 small, squarish, slightly imbricated ribs, which show a tendency to hecome 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 ear sculptured by + or 5 imbricated radiating ridges; byssal notch distinct; posterior ear sculptured in a similar manner to the anterior. Left valve similar to the right except that in the former the ribs are slightly more rounded and the anterior ear has no notch. Dimensions.—Alt. 30 mm.; long. 31 mm.; hinge line 18 mm.; diameter 6 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 admirable as a diagnostic form for the Tejon. The type and several other 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 Astarte oil wells, Ventura County. At this locality it was associated with the following characteristic Tejon fauna: Avcu sp., Cardiwn brewer, Mereatriz horni. Modiolus OTNATUS, Tipes Sp.-, Turritela UDUSAILGA. Veneri- cardia planicosta Lam. var. hornii. The types of P. calhinsi are now in the collection of the University of California. Named in honor of Mr. Frank C. Calkins, of the United States Geological Survey. RANGE. Eocene (Tejon). Sisar Valley, Ventura County (Fairbanks). Prcren (CHLAMYS) LANDESI n. sp. Pl. II, figs. 3, 4, and 5. Description.—Sshell averaging about 34 millimeters in altitude, about as long as high, subcircular, inequivalve, equilateral, thin, slightly ventricose, and with serrate margins. Right valve more ventricose than left, and flattening toward the periphery in the adult; surface ornamented by from 25 to 40 subequal, rounded, more or less imbricate ribs, separated from each other by subequal, concave-bottomed interspaces, which average about as wide as the ribs; hinge line slightly longer than one-half length of disk; ears somewhat unequal, the anterior being slightly the longer; anterior ear sculptured by 4 prominent radials, while the posterior has from 6 to 8 less prominent ones; byssal notch deep: whole surface of disk and ears crossed by numerous fine imbricating lamelle. Left 52 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. vaive more compressed than right, similarly seulptured, but with both ears slightly obliquely truncated, the anterior one showing a broad shallow notch. Hinge and muscle scars similar to 7. zslandicus. Dimensions.—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 about the same, but the ribs are quite variable, as regards both number and shape. In most cases the ribs are evenly rounded and about equal in width to the interspaces, but in some cases they are ridgelike and narrower than the interspaces. In some specimens a few of the ribs become dichotomous 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 several] intercalaries beyond the line of contraction. Some of the specimens of P. /andesi remind one somewhat of: P. membranosus Morton, from the Eocene of North Carolina, although the latter has more and narrower ribs, and is ornamented by finer imbricating sculpture than the former. . ?. /andesi is distinguishable trom /. proavus by its relatively longer disk and fewer but more prominent, regular, and less imbricated ribs. It is distinguishable from P. calkinsi by its smaller size when adult, fewer but more elevated ribs, and relatively much shorter hinge line. P. landesi is found quite abundantly in a dark-greenish sandstone bed that outerops about 100 yards west of the junction of Stillwater 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 first locality. It is associated in this formation with a characteristic Kocene fauna, among which are the following species: Venericardia planicosta Lamarck, Thracia diller’? Dall, Crassatellites sp., Meretriv sp., Ostrea sp., Pteria (ef.) limula Conrad, Cardium 2 sp., Barbatia sp., Glycymeris sp., Corbula sp., Callista sp., Turritella (cf.) wvasana Conrad, Fusus 4 sp., Ocinebra sp., Ranella sp., Calyptrophorus sp., Lunatia sp., Turbinella (4) sp., Murex 2 sp., Conus sp., Cassis sp., Tritonium sp., Dentalium (ct.) cooper? Gabb, and Nautilus sp. This horizon is probably upper Eocene, possibly above the Tejon. Named in honor of Prof. Henry Landes, Seattle, Wash. RANGE, Eocene (probably upper). Vicinity of Little Falls, Lewis County, Wash. U. 5. Nat. Mus. locality 4019; 4024. (Arnold.) PrcTEN (CHLAMYS) PROAVUS 2. sp. Pl. II, figs. 6, 7, and 8. Description.—Shell averaging about 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 umbo. Left valve with numerous more or less unequal, narrow, thread-like, imbricated ribs, between which are occasionally much finer intercalaries; interspaces about as wide as ribs, channeled and flat bottomed; whole surface of disk and EOCENE PECTENS. 53 ears ornamented by numerous, sharp, imbricating lamellae of growth, which appear more prominently on the anterior portion of the disk; posterior ear short, slightly obliquely truncated, and sculptured by numerous radials and imbricating lamelle; anterior ear unknown, but probably much longer than posterior. Dimensions. —Alt. 38 mm.; long. 30 mm.; hinge line (restored and approximate) 18 mm.; diameter 7 mm. This species is closely allied to 2. trashi Gabb, from the Cretaceous of the Pacific coast. It differs from the latter, however, in not having the diagonal microseropic sculpture so characteristic of that species. A fragment of a much larger specimen than the type of 7. proavus, from the same beds and probably the same species, shows, near the periphery, narrow ridge-like ribs separated by rather wide interspaces in each of which are two or three fine thread-like riblets. (Pl. I, fig. 8.) The type of P. proavus, 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 Creek and San Lorenzo River, San Mateo County. At this locality it was associated with the following fauna: Terebratulina tejonensis, Tritonium (et.) californicum, Patella (ct.) traski, Helcion dichotoma, Ostrea (att.) idriaensis, Turbo sp.. Acmexa or Patella sp., Terebratula n. sp., Cidaris (4) spines Semele 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 Eocene), 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. Lower Eocene (Martinez’). Between the headwaters of Pescadero Creek and the San Lorenzo River, San Mateo County (H. 5S. Gay; Arnold). PECTEN (PROPEAMUSIUM) INTERRADIATUS GABB. Pl. II, figs. 9, 10, and 11. 1869. Pecten interradiatus Gabb, Pal. Cal., vol. 2, 1869, pp. 199-200, pl. 33, figs. 98, 98a. 1888. Pecten interradiatus Gabb, Cooper, Seyenth Ann. Rept. Cal. St. Min., 1887, p. 289. (From “Cretaceous B,’’ which is Eocene). Description.—** Shell small, subcircular, equivalve, equilateral, compressed, thin; upper [left] valve, ears equal, moderately large; lower [right] valve, right ear long, deeply and narrowly emarginate. Surface marked by very numerous fine radiating lines, and obscure lines of growth. Internal surface of both valves bearing 8 straight, equidistant, large ribs of variable length among themselves, extending from the beaks to near the middle of the shell and ending abruptly.” Dimensions.—Alt. 25 mm.; long. 24 mm.; hinge line 15mm.; diameter 2.5 mm. This species may be distinguished from P. stanfordensis by its larger size, narrower anterior ear of right valve, and fewer number of interior ribs. It is also distinguishable from P. clallamensis and P. waylandi by its larger size and incon- spicuous external surface sculpture. b4 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. Gabb states that the type of P. éaterradiatus is from the **buff-colored shale vast of New Idria, at or near the summit of the Tejon Group” [Eocene], where he found it very abundant. Two specimens from the collection of the University of California, which were collected by Mr. H. W. Turner at New Idria, are in a hard, dark-colored shale. , A Pecten allied to P. interradiatus, accompanied by the following note, was sent to the writer by Dr. J. C. Merriam, of Berkeley: ‘*‘ Road cutting below Professor Richer’s house at mouth of Strawberry Canyon, Berkeley. Cutting now walled up. A.C. L. Cretaceous shale.” This species, which is represented by an internal cast, is 12 millimeters in altitude, 10 millimeters in longitude, and has a hinge line 8.5 millimeters in length. It has 10 prominent rounded internal ribs extending from the umbo nearly to the periphery, and in several of the broad interspaces a rounded intercalary, which begins at a distance of about 7.5 millimeters 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 posterior, arcuate in front, and has but a faint suggestion of a byssal notch. The figures of P. /nterradiatus, which are natural size, are copied from the originals of the type in Pal. Cal., vol. 2, pl. 33, figs. 98, 98a. RANGE. Eocene (upper Tejon). New Idria, San Benito County (Gabb: Turner). OLIGOCENE PECTENS. {Those known first to appear in the Oligocene formations. ] Prcren (PECTEN) SAN IRITTZENRTS - ECTEN (PECTEN) SANCTACRUZENSIS N. sp. Pl. III, figs. 12 and 13. 1903. Pecten (Pecten) twobarensis Arnold, MS. Description. —Shell averaging about 50 millimeters in altitude, slightly longer than high, plano-conyex, equilateral, rather thin; base regularly rounded; sides only slightly concave above; margins smooth. Right valve quite convex and ornamented with about 12 prominent, perpendicular-sided, slightly convex-topped ribs, separated by flat-bottomed, channeled interspaces about equal 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 byssal notch and fine, sharp concentric lines; posterior similarly sculptured, but rectangularly truncated. Left valve flat, with slight concavity near umbo; lateral areas rather prominent; ribs squarish, with slightly convex tops narrower than those of the right valve and with proportionally wider interpaces; ears subequal, rectangularly truncated, and with surface sculptured by numerous fine, sharp incremental lines. Dimensions.—Alt. 52 mm.; long. 55 mm.:; hinge line 32 mm.; diameter about 13 mm.; unbonal angle 110 _ This species is allied to P. be//us and may be its precursor, as it 1s very similar to the latter in most respects. P. sanctecruzensis may be distinguished OLIGOCENE PECTENS. 5D) from P. bellus by its fewer ribs (11 instead of 14) and relatively smaller size when adult. P. sancteecruzensis is so far known only from beds which appear to be tran- sitional from the Oligocene to the lower Miocene. At locality No. 111(L. S.J. U. Geol. Survey) on Twobar Creek, one-fourth mile above its junction with San Lorenzo River, Santa Cruz County, the type was found associated in a soft sand- stone with the following species: Pecten branneri n. sp., Cythera (cf) vespertina, Tritonium sp. No. 1, Corbula (4) sp., Yoldia (cf:) impressa, Nucula un. sp. (large, with coarse sculpture), Zeda sp. B. and C., Cidaris (4) spines, Call/sta sp., Tellina (Angulus) sp., Cardium n. sp., near COOPEr 1, Teredo Spe Chione (cf.) mathewsoni. One mile southeast of Cowell’s asphaltum quarry (locality 30), near Santa Cruz, P. sancteecruzensis is associated with P. peckhami, Nucula sp., Phacoides sp., and Chione sp. The type, a beautifully preserved mold of a left valve, is now in the collection of the department of geology, Stanford University. A small cobblestone con- taining two right and two left valves of 7. sanctecruzensis was found by Miss L. J. F. Hecox, of Santa Cruz, as float in Bear Creek, about 2 miles from the type locality. One of these right valves is figured and serves as a cotype. RANGE. Oligocene-Miocene. Twobar Creek and Bear Creek, Santa Cruz County (Arnold; Hecox). PrcrEeN (CHLAMYS) BRANNERL Nn. sp. Pl. III, figs. 9, 10, and 11. Description.—Adult shell averaging about 80 millimeters in altitude, bigher than long, equivalve, slightly convex, and equilateral, except for ears; sides only slightly concave above; base regularly rounded below. Right valve with from 20 to 22 prominent, narrow, more or less scaly or spiny ribs, which in the adults are sometimes medially suleated or dichotomous; interspaces generally much broader than the ribs, channeled and usually containing a spiny or scaly inter- salary rib; whole surface sculptured by imbricating incremental lines, often also by microscopic reticulations; hinge line about two-thirds leneth of disk; anterior ear much produced and sculptured by 6 to 10 imbricated ridges, which are separated by equally wide reticulated interspaces; byssal notch profound; posterior ear about three-fifths length of anterior, and sculptured similarly. Left valve similar to right. Dimensions. —Alt. 65 mm.; long. 58 mm.; hinge line 40 mm.: diameter 14 mm.: umbonal angle 83°. This species varies considerably in the degree of importance of the minor sculpture, such as reticulation, imbrication, and size of the suleations and intercalaries. Although unquestionably allied to the Chlamys group, it has larger posterior ears than other species of the group that have come under the writer's notice. 2. branneri resembles P. islandicus in size, outline, and general sculpture, but is distinguishable by haying only about one-half as many ribs and much larger posterior ears. 56 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. So far as is known, P. branneri 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 Lorenzo 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, Leland 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). Twobar Creek, near Boulder Creek, Santa Cruz County (Newson; Arnold). PrcreNn (PSEUDAMUSIUM) PECKHAMI Gabb. P|. III, figs. 6, 7, and 8. 1869. Pecten peckhami Gabb, Pal. Cal., vol. 2; 1869, pp. 59, 60, pl. 16, figs. 19 and 19a. 1888. Pecten peckhami Gabb, 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. Description.—Shell averaging about 20 millimeters in altitude, subcircular, sub- equivalve, 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 undula- tions. 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 striz also. Dimensions.— Alt. 21 mm.; long. 21 mm.; hinge line 14 mm.; diameter 2 mm. Asa 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 ear of the right valve is almost always present and is quite characteristic. In California this species is found from the San Lorenzo formation (Oligocene) to the Monterey or middle Miocene. 7. pechkhami is found abundantly in the Monterey shale in Newell Creek canyon, 2 miles above Ben Lomond, Santa Cruz County, where it is associated with Arca montereyana Osmont, Corbula sp., Cyth- OLIGOCENE PECTENS. Nf erea sp., Diplodonta n. sp., Venericardia (4¢) n. sp., Leda 2 n. sp., Phacoides sp.. Semele n. sp., and Tellina ct. congesta 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 near the base of the Oligocene-Miocene section between Bean and Restoration points, west of Seattle, King County, Wash., associated with Clypeaster (%) sp., Tercbratula sp., and Teredo sp. At Freshwater Bay, Clallam County, Wash., it is found with Doliwn petrosum Conrad, Fusus sp., Natica or Lunatia sp., Nucula et. decisa Conr.. Volutilithes n. sp., Dentalium substriatum Conrad, Phacoides acutilineatus Conrad, Solemya sp., Leda sp., and Marginella or Erato sp. Farther west along the Strait of Juan de Fuca, 14 miles east of Gettysburg, Clallam County, Wash., P. peckham7 is associated with Wiucula sp., Leda n. sp., Dentaliuin substriatum Conrad, Natica sp., ete. One of the specimens of PP. 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. RANGE. 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, Monterey 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 4113, between Bean and Restoration points, King County; locality 4121, Freshwater Bay; location 4120, 2 miles west of Port Crescent; locality 4114, 15 miles east of Gettysburg, Clallam County (Arnold). PrcTEN (PROPEAMUSIUM) CLALLAMENSIS n. sp. Pl. III, figs. 1, 2, 3, and 3a. Description.—Adult shell averaging about 10 millimeters in altitude, subeir- cular, equivalve, equilateral, thin, compressed, and with smooth margins. Right valve ornamented externally by numerous equally elevated, sharp, slightly imbricate, concentric lamelle, 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 lamelle and 5 or 6 slightly elevated, unequally spaced radials; 58 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. 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 6 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 lamelle which, sloping at an angle of about 45° 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 sculptured 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. This beautiful little Pecten appears to be allied to P. stanfordensis, 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 2. clallamensis is a left valve (U.S. N. M. No. 164922) and was found at locality 4100, 15 miles east of Pillar Point, near the mouth of the Pysht River, Clallam County, Wash., where it was associated with Aturta ef. ziczac Sowerby, Doliwm petrosum Conrad, Husus sp., Natica or Lunatia, Marginella or Erato sp., Nucula sp., Leda sp. (large, smooth), Zel/ina (Angulus) sp., Solemya sp., Dentalium substriatum 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 Zerebratula sp., Turritella sp., Marginella or Erato sp., Natica or Lunatia sp., Glycymeris sp., and Astyris sp. Both of the localities at which 7. clallamensis have so far been found are in the lower portion of the Oligocene-Miocene series. RANGE. Oligocene-Miocene. Mouth of Pysht River, Clallam County, and Bean Point, west of Seattle, King County, Wash. (Arnold). PECTEN (PRoPEAMUSIUM) WAYLANDI Nn. sp. 1 Pl. ILI, figs. 4 and 5. Description.—Adult shell averaging about 9.5 millimeters in altitude, somewhat longer than high, subcireular, equivalve, equilateral, 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 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; byssal 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, conyex-topped riblets, which are widely separated and which terminate abruptly at about 6 to 8 millimeters from the umbo; these MIOCENE PECTENS. 5Y 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 milli- meters, ornamented by 8 more or less prominently elevated, narrow, convex-topped radiating ridges, corresponding with the same number 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 byssal notch in the anterior one. Dimensions. —Alt. 9.5 mm.; long. 12 mm.; hinge line 5.5 mm.; diameter about 0.75 mm. This little Pecten is closely allied to P. stanfordens/s, 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. 7. waylandi is distinguishable from P. clallamensis, with which it is associated, by its relatively longer disk, simple and less prominent external sculpture, and fewer (8 instead of 9) internal riblets. It is allied to P. ‘nterrvadiatus Gabb, but is much smaller, being only about one-half as large, has a much shorter hinge line, and its left yalye is much more strongly sculptured; it also occurs in a horizon probably later than that in which 7. interradiatus is found. The type of P. waylandi (U.S.N.M., No. 164924) was found with the type of P. challamensis at locality 4100, 14 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. clallamensis. The cotype of P. waylandi (U.S.N.M., No. 164925), a mold of the interior of a right valve, was found at locality 4115, 24 miles west of Gettysburg, Clallam County, Wash., where it was associated with Fusus sp., Leda sp., Macoma or Tellina sp., and Aturia ef. ziczac Sowerby. The faunas associated with 2. wayland/, 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. Russell G. Wayland, of Seattle, Wash., who assisted the writer during part of his paleontological reconnaissance trip along the northwestern coast of Washington in the summer of 1904. RANGE. Oligocene-Miocene, 24 miles west of Gettysburg, and 14 miles east of Pillar Point. near the mouth of the Pysht River, Clallam County, Wash. (Arnold) MIOCENE PECTENS. [Those known first to appear in the Miocene formations.] PECTEN (PECTEN) CARRIZOENSIS n. sp. PRESSLY. fess lelianelib sos. and) 3a: 1898. Pecten sp. indet., Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, p. 706, line 13. Description.—Shell averaging about 42 millimeters in altitude, longer than high, inequivalye, plano-convex, equilateral, and with smooth margins; base evenly rounded; sides concave above. Right valve convex, ornamented by about 18 or 60 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. 19 prominent, square, flat-topped, medially sulcated ribs; interspaces channeled and slightly narrower than ribs; whole surface sculptured by fine, regular, concentric incremental lines; hinge line less than one-half length of disk; ears subequal, conyex, and ornamented by concentric lines. Left valve flat or slightly concave. ornamented by about 17 prominent, equal, equidistant, narrow, convex-topped ribs, which are separated by flat-bottomed interspaces much wider than the ribs; surface sculptured by numerous fine, regular, wavy, concentric lines; ears concave and sculptured by concentric lines. Dimensions.—Alt. 36 mm.; long. 40 mm.; hinge line 15 mm.; diameter 8 mm.; umbonal angle (left valve) 105°. This species belongs to the group of which /. diegenss is the living member. P. carrizoensis, P. stearnsii, and P. diegensis taken in chronologic order as above may represent 1 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. carrizoensis differs from the other two members 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. carrizoensis and found to be of this species. The type locality of P. carrizoensis 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 Part I, p. 22, and list of Santa Rosalia, Lower California, fossils under P. cerro- sensis var. mendenhalli, p. 85.) The type of P. carrizoensis, which was collected by Dr. Stephen Bowers, is now in the collection of Delos Arnold. RANGE. Miocene. Head of Garnet Canyon, 12 miles north of Mexican boundary, San iego Coun owers); Santa Rosalia, Lower California, west of and across Diego County (Bowers); Santa Rosalia, L Calif t of and acro the Gulf from Guaymas, Mexico (G. P. Merrill; E. Palmer). PrcTEN (PECTEN) KEEPI 0. sp. Pl. V, fig. 1; Pl. VI, figs: 1 and 1a. Description.—Shell averaging about 75 millimeters in altitude, longer than high, plano-convex, equilateral, and with smooth margins; sides concave above; lateral area very broad. Right valve ventricose and ornamented by about 20 low, broad, rounded ribs, separated by shallow interspaces in which are low, broad interealaries; 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, some- what convex, rather obliquely truncated and turned up slightly at the corners; sculpture of ears consists of fine 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, rather flat-topped ribs; interspaces somewhat wider than the ribs; surface sculptured by fine incremental lines; ears concave, obliquely truncated and sculptured by more or less irregular concentric lines. Dimensions.—Alt. 75 im.; hinge line to ventral margin 72 mm.; long. 82 mm.; hinge line 35 mm.; diameter 20 mm.; umbonal angle (left valve) 102°. This species is distinguishable from P. vogdesi and P. excavatus, which it resembles in general characteristics by its greater relative length, somewhat less convexity, greater umbonal angle, broader lateral areas and lower ribs. This species is found associated with P. carrizoensis and Ostrea vespertina 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. RANGE. Miocene. Eight miles north of Mexican boundary, in Alverson Canyon, Carrizo Creek district, San Diego County (Bowers); Santa Rosalia, Lower California, west of and directly across the Gulf from Guaymas, Mexico (E. Palmer). PrcTeNn (PATINOPECTEN) COOSENSIS Shumard. Pl. VI, fig. 2; Pl. VII, figs. 2 and 2a. 1858. Pecten coosensis Shumard, Trans. St. Louis Acad. Sci., vol. 1, pt. 2, 1858, p. 122. 1864. Pecten coosaensis Shumard, Meek (typ. err.), Miocene check list, Smithsonian Miscell. Coll., 1864, p. 3 (fide Dall, 1898). 1869. Pecten coosensis Shumard, Gabb, Pal. Cal., vol. 2, 1869, p. 122. 1898. Pecten (Patinopecten) coosensis Shumard, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 700, pl. 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 29 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 fine 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; pos- terior ear rectangularly truncated, and sculptured by sharp incremental lines and sometimes by obsolete radial ridges. Left valve with narrower, rounded, concaye- sided ribs and wider, round-bottomed interspaces; sculpture of numerous, sharp, 62 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. raised, concentric lines; ears subequal, and having incremental and sometimes obsolete radial sculpture. Dimensions.—Alt. 110 mm.; long. 115 mm.; hinge line 54 mm.; diameter 26 mm. This fine species is distinguishable by the great number and shape of its ribs. Specimens found at Howe’s place, northeast of Corvallis, Benton County, Oreg., have only from 25 to 27 ribs on the right valve. Otherwise the specimens are similar to the typical form. Found abundantly in the Empire beds at Coos Bay, Oregon, whence the type came. RANGE. Miocene. Coos Bay, Oregon (Shumard; Dall; A. W. Crawford and others); Howe’s place, northeast of Corvallis, Benton County, Oreg. (Diller). PECTEN (PATINOPECTEN) DILLERT Dall. JEL Wa ste 1901. Pecten (Lyropecten) dilleri Dall, Nautilus, vol. 16, no, 10, Feb., 1901, p. 117. The original description is as follows: Description. —* Shell large, averaging about 190 millimeters in altitude, rather compressed, nearly orbicular with a relatively short. straight, hinge line, dorsally rectangular, nearly smooth, subequal ears, the posterior with 3 small riblets; a well- marked though shallow byssal fold; and moderately thick valves. The right valve is somewhat more convex and strongly sculptured, bearing 29 to 30 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 scaly at their sides. The sculpture of the left valve is less pronounced, hidden in the matrix, but apparently similar.” Dimensions.—‘* Alt. 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. purisimaensis, and is no doubt genetically related to that form. Although the left valve of P. d//er7 has not been seen, it is safe to assume from the close relationship of this species and 7. purisdmaens/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. dilleri is so far known only from beds of probable upper Miocene (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. RANGE. Upper Miocene or lower Pliocene. Rio Dell, Eel River, Humboldt County (Dall; Diller). MIOCENE PECTENS. 63 PECTEN (PATINOPECTEN) OWENT nN. sp. Pl. VIII, figs. 1, la, and 1b. 1888. Pecten pabloensis Cooper (not Conrad), Seventh Ann. Rept. Cal. St. Min., 1888, p. 258 (‘‘ Foxins, Santa Barbara County”’ record, only). 1898. Pecten sp., Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 705, line 27. Description.—Shell averaging about 85 millimeters in altitude, slightly longer than high, inequivalve, equilateral, and with more or less serrate margins; base regularly rounded; sides somewhat concave above. Right valve much more con- vex than the left, with 15 or 16 subequal, strong, elevated, squarish ribs, which become more or less deeply medially suleated after about 40 or 50 millimeters in length; interspaces about as wide as ribs, channeled and ornamented with more or less prominent rounded intercalary riblets; whole surface of disk sculptured by fine lines of growth; hinge line considerably longer than length of disk; anterior ear slightly longer than posterior, obsoletely radially ribbed, and with sharp incre- mental sculpture; byssal notch quite prominent and equal in width to about one- third width of ear; posterior ear rectangularly truncated and with prominent incremental, but nearly obsolete, radial sculpture. Left valve less ventricose than right; ribs quite high, narrow, and rounded; interspaces much wider than ribs, with round bottoms, and each ornamented by a prominent rounded intercalary rib; surface sculptured by numerous sharp, regular, concentric lines; ears slightly obliquely truncated and sculptured as those of right valve. Hinge as in P. COUPINUS. Dimensions.—Alt. 85 mm.; long. 90 mm.; hinge line 54 mm.; diameter 24 mm. This species is quite closely allied to P. heuley/, of which it is probably the precursor. It may be distinguished from the latter by its smaller size, greater conyexity, fewer and stronger ribs, more prominent intercalary riblets on the right valve, and relatively much longer hinge line. P. oweni is found in a horizon which is probably low down in the Pliocene, and also in deposits, such as those at Foxin’s ranch, Santa Barbara County, from which the type comes, that may be upper Miocene. Specimens of this species have been found in the lower part of the Purisima (Pliocene) formation north of the mouth of Purisima creek. There appears to be more or less of a gradation from P. owent to P. healeyi as we go up in the Purisima formation. The rather convex, 17 and 18 ribbed forms of P. healey/, mentioned as occurring at Lobitas and Purisima, seem to furnish a more or less intimately connecting link between the latter species and ?. owenz. The type of P. oweni, which is figured, is now in the collection of the University of California. This specimen was labeled **P. publoensis” by Doctor Cooper and furnished the erroneous record of P. pabloensis from ** Foxins, Santa Barbara County” (see Cooper, 1888, p. 258). In the Pliocene beds of Temescal Canyon, near Santa Monica, Los Angeles County, 7. oweni is associated with P. stearnsii, P. estrellanus var. cataline, P. cerrosensis and other Pliocene species. 64 TERTIARY AND QUATERNARY PEOTENS OF CALIFORNIA. P. oweni is associated with the following possibly upper San Pablo (upper Miocene) fauna at the Double Eagle wells, in the Coalinga district, Fresno County: Tamiosoma gregaria, Pisania (aff.) fortis, Tresus (2) sp., Glycymeris patulus (2), and Saridomus gibbosus. This fauna, although containing Zamdosoma gregaria, lacks the two most characteristic species of the San Pablo formation of this locality, viz, Peeten estrellanus and Ostrea 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. owen? may, therefore, be considered as only occurring in the upper part of the San Pablo, or, in other words, in beds transitional from the San Pablo (upper Miocene) to the Purisima (lower Pliocene). Just above the first railroad bridge across Wartham Creek, Fresno County, 7. owen? 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: Savidomus gibhosus, Chione n. sp. (large, coarse sculpture), and Tamiosoma gregaria. A 17-ribbed right valve of P. oweni was found 2 miles south of San Lucas, Monterey County, associated with Pecten estrellanus and varieties, Astrodopsis tumidus, Balanus estrellanus, ete. 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 Valley, 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 collec- tion); Double Eagle wells, Coalinga district, Fresno County (Eldridge); railroad bridge across Wartham Creek, Fresno County (Eldridge); San Lucas, Monterey County (Hamlin; Arnold). PrEcTEN (PATINOPECTEN) PROPATULUS Conrad. Pl. VII, fig. 1; Pl. EX, figs. 1, 1a, 2, and 2a. 1849. Pecten propatulus Conrad, Geol. Wilkes Expl. Exped., app. 1, 1849, p. 726, pl. 18, figs. 13, 18a. 1864. Pecten propatulus Conrad, Meek, Miocene Checklist, 8. I. Mise. Coll., 1864, p. 26 (fide Dall). 1869. Pecten 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, Dall, Trans. Wagner Free Inst. Sci., 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 with 15 or 16 subequal, squarish ribs, some of which are generally obsoletely medially suleated; interspaces subequal, flat-bottomed, about as wide as ribs and sometimes containing faint intercalaries; whole surface ornamented with fine, sharp, MIOCENE PECTENS. 65 incremental lines; hinge line less than one-half length of the disk; anterior ear slightly longer than posterior, arcuate-ended, and ornamented above the byssal area by 4 or 5 prominent radiating riblets, which, with the byssal area, are crossed by numerous fine concentric lines; posterior ear rectangularly truncated, and orna- mented by several radiating riblets and numerous incremental lines. Left valve somewhat similar to right, but with narrower, ridge-like ribs and the broader inter- spaces sometimes showing a more or less prominent intercalary riblet in the later stages of growth; surface, when perfect, microscopically tessellated; ears radiately and concentrically sculptured. Dimensions.— Alt. 93 mm.; long. 93 mm.; hinge line 38 mm.; diameter 12 mm. One of Conrad’s cotypes from the Miocene of Astoria, Oreg. (U. S. Nat. Mus., 154155), shows the ribs and surface of the disk in a perfect state of preservation. The ribs on the right valve are broad, squarish, and all more or less medially sul- cated, and with the surface sculptured by fine lines of growth and microscopic tessellations. The left valve shows more or less prominent intercalaries in each interspace, and has the whole surface beautifully tessellated. This species has been confused by some authors with P. cawrinus Gould, from which it differs by being smaller, more convex, and having fewer (15 instead of 20) ribs, and a tessellated surface on the left valve. A P. propatulus is common in the Astoria Miocene of the Columbia River. A specimen probably of this species, haying 15 primary ribs on each valve, intercalary riblets in most of the interspaces, and the typical tessellated surface, was found at Newport, Yaquina Bay, Oreg. A variety of P. propatulus, with possibly an average of one or two more ribs and the intercalaries and medial sulcations slightly more prominently developed, is found at Griswoldsville, San Benito County, Cal., and at several other local- ities in the southern Mount Diablo Range. At Griswoldsville P. propatulus is associated with the following species: Phacoides acutilineatus, Arca canalis, Panopea generosa, Cryptomya californica, Nucula castrensis, Sigaretus sp., Trochita filosa, Dosinia sp. (thin, flat). A more or less close relationship appears to exist between P. propatulus, P. oweni, and P. healeyi. The last is distinguishable by its more numerous ribs (having generally 20 or more), and P. owen? by its much stronger intercalaries and deeper medial suleations. P. propatulus is found in a horizon which is probably somewhat lower than any in which either P. owen? or P. healeyi occur. RANGE. Miocene (middle? and upper?). Clallam Bay, Strait of Fuca, Washington (Diller; Arnold); Astoria, Oreg. (Dana; Dr. H. C. Kinney, and others); Newport, Yaquina Bay, Oreg. (H. Hill); Point Simpson, B. C. (No. 3518, Cal. Acad. Sci. Coll.); Griswoldsville, San Benito County, Cal. (Turner, Cooper). 17260—No. 47—06—5 ~ for) o> TERTIARY AND QUATERNARY PEOCTENS OF CALIFORNIA. Prcren (CHLAMYS) FUCANUS Dall. Pl. X, figs. 1, 2, and 2a. 1898. Pecten (Chlamys) fucanus Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 704, pl. 26, fig. 7. 1904. Pecten (Chlamys) fucanus Dall, Harriman Exped. Repts., Alaska geology, Neozoic invert. fossils, p. 115. 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 + prominent radials and fine, imbricating, incremental lamelle; the posterior rectangularly truncated and sculptured by more, but less prominent radials and. fine concentric lamelle; 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 inter- spaces, which often carry one or more elevated riblets; the submargins are radially threaded, as are the subequal ears, which are rectangularly truncated, and also bear marked concentric lamelle; 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 Ohlamys, but, instead, shows in its sculpture some affinity to certain species of Patinopecten. The type of P. fucanus (U.S. N. M., No. 107790) is the mold of the exterior and interior (a cast of the former being Pl. 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., Crepidula sp., Dentalium sp., Mytilus sp., Mactra or Spisula sp., Venericardia sp., Nucula (cf.) decisa Conrad, Leda sp., Tellina (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 /%cten (probably propatulus Conrad) with medially suleated ribs on the right valve. RANGE. Miocene. Between Clallam Bay and Pysht River, Clallam County, Wash. (Diller; Arnold); north end of Popoff Island, Alaska (Dall). PrCTEN (CHLAMYS) HAMLINI n. sp. Pl. XI, fig. 2. Description.—Type somewhat distorted but originally about 60 millimeters in altitude, and probably somewhat shorter than high; moderately 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 2. watts/, 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 geologie position of P. hamlini is somewhat uncertain, although the meager fauna with which it is associated at the type locality points toward its cor- relation with the Vaqueros or lower Miocene. The type of P. hamlini (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. estrellanus Conrad, Chione n. sp. (large, and with coarse sculpture), Chione (cf.) mathewsonii Gabb, and Mactra (att.) catdliformis Conrad. A specimen, which is probably a left valve of 7. Aamlini, was found asso- ciated with Pecten branner? in the lower Miocene at Tuff Hill, near Stanford University, Santa Clara County. ‘This specimen has three widely separated, nar- row, ridge-like ribs, and the interspaces are ornamented by a number of rather coarse radiating riblets; altitude 31 millimeters. RANGE. 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). PECTEN (CHLAMYS) NUTTERI 0. sp. Pl. XI, figs. 3, 4, and 4a. Deseription.—Shell averaging about 65 millimeters in altitude, slightly higher than long, inequivalve, equilateral, more or less ventricose, and often showing 68 TERTIARY AND QUATERNARY PECTENS 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, rather prominent, flat-topped ribs, each of which is channeled by one or more deep, narrow, concave suleations which divide the primary rib from umbo to margin into two or more generally unequal but evenly couvex 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 squamose 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 nearly one-half length of disk; anterior ear prominent and sculptured by 5 or 6 elevated radi- ating 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 with unequal, rather narrow, convex ribs, the alternate ones being more prominent than those inter- mediate; 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 by 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 crura adjacent to the umbonal pit in the right valve. Dimensions.—Alt. 64 mm.; long. 57 mm.; hinge line 27 mm.; diameter 21 mm. This species is allied to P. parmeleet and P. wattsi but is distinguishable by having a larger number of ribs, which are also narrower and more coarsely radially sculptured. The Miocene forms of /. nutter’ 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. nutter’, 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 PECTENS. 69 PrECTEN (CHLAMYS) SESPEENSIS Nn. sp. Pl. VIII, figs. 2; 2a, and 3. 1888. Pecten hastatus Cooper (not Sowerby), Seventh Ann. Rept. Cal. St. Min., 1888, p. 257 (Miocene of Estrella, San Luis Obispo County?). Description.—Shell averaging about 50 millimeters in altitude, higher than long, inequivalve but both valves equally slightly 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 gen- erally 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 incre- mental lines; posterior ear oyer one-half as long as anterior, and sculptured similarly ; byssal notch prominent. Left valve with about nine prominent, narrow, squarish, somewhat conyex-topped ribs separated by much broader interspaces, along the bottom of which run one or more thread-like intercalaries of greater or less prom- inence; ears similar to those of the right valve. Dimensions.—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. hastatus in size, shape, and number of major ribs, but differs from the latter in having longer anterior ears and scarcely any secondary sculpture of minor riblets and scaly surface. P. sespeens7s approaches more closely to the smooth form of /. Hastatus found in the Pliocene, but may be easily dis- tinguished 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 cotype, 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. Eldvidge found P. sespeensis associated with Turritella (ct.) hoffmanni, Ostrea sp., and Modiolus sp. RANGE. Miocene (lower.) Sespe oil district, Ventura County (Watts); Tar Creek, Ventura County (Eldridge). PrEcTEN (CHLAMYS) SESPEENSIS var. HYDEI n. var. Pl. V, figs. 3, 3a, and 35. 1903. Pecten (Chlamys) hydei Arnold. MS. Description.—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 PECTENS 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. hastatus var. hericius 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 inter- spaces. The shell has a tendency to contract somewhat upon reaching an altitude of about 35 or 40 millimeters. P. var. hydei 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 Scutella Suirbanksi, Ostrea sp., Arca sp., and Balanus. Near the Torrey wells, Ventura County, the same gentleman found it with J/yéclus mathewsonii, and Ostrea (aft.) 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 Zwrritella hoff- manni, 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). Prcren (LYROPECTEN) BOWERSI n. sp. Pl. XII, figs. 1 and 2; Pl. XIII, figs. 1 and 1a. 1856. ? Pecten nevadanus Conrad, Pac. R. R. Rept., vol. 5, p. 329, pl. 8, fig. 77. Description.—Shell averaging about 150 millimeters in altitude and length, inequivalve, equilateral, rather thick, ventricose, and with smooth margins; hase 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 obsoletely 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 PECTENS. alt toward the apex; byssal notch wide and of medium depth; posterior ear rectan- gularly truncated, radiately ribbed, and crossed by 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. Dimensions.—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 characteristic. P. bowers is placed in the section Lyropecten because of its hinge and general affinity 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. bowersi ranges from the lower to possibly the middle Miocene, being found associated in some localities with P. magnol/a, and in others with P. discus. 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 infor- mation 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 County (R. E. Maynard); Santa Monica Mountains, Los Angeles and Ventura counties (Bowers). Station No. 550, Santa Ana Mountains (Watts). PECTEN (LYROPECTEN) CRASSICARDO Conrad. Pl. XVI, figs. 1 and la; Pl. XVII, figs. 1, la, and 16; Pl. XVIII, figs. 1, 2, and! 2a. 1856. Palliwm crassicardo Conrad, Proc. Acad. Nat. Sci. Phila., 1856, p. 313. 1857.? Spondylus [=Pecten] Estrallensis Conrad, Proc. Acad. Nat. Sci. Phila., first series, vol. 8, for 1856, 1857, p. 316. 1857.? Spondylus [= Pecten] Estrellanus Conrad, Pac. R. R. Rept., vol. 7, 1857, p. 191, pl. 1, fig. 3; not ; Pallium [= Pecten] estrellanum Conrad, Pac. R. R. Rept., vol. 6, pt. 2,1856, p. 71, pl. 3, fig. 15. 1863. Pecten 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). 72 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. 1894. Pecten estrellanus Conrad, Cooper, Bull. Cal. St. Min. Bureau, No. 4, pt. 5, 1894, p. 57 (in part). 1898. Pecten magnolia Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, p. 702 (in part); not Pecten magnolia Conrad, Pac. R. R. Rept., vol. 7, 1857, p. 191, pl. 1, fig. 2. 1901. Pecten magnolia Dall, Nautilus, vol. 14, 1901, p. 117 (in part); not P. magnolia Conrad, 1857. 1904. Pecten (Lyropecten) diabloensis Arnold, MS. (a distorted specimen of P. crassicardo being the type). Description.—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, perpendicular- sided, conyex-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 striw 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. Dimensions.— Alt. 140 mm.; long. 138 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 many as six or seyen 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. crassicardo is characterized by its comparatively few ribs, which, with the interspaces, are more or less prominently striated. It is distinguishable from P. ashley/, by its relatively much greater length, fewer ribs, and tendency to be con- stricted 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 ears, and its tendency to become constricted; distinguishable from 7. estrellanus, with which it is often associated, by its fewer and rather finely striate ribs and lack of a major interealary riblet (the bottoms of the interspaces of P. crassicardo 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. estrellanus generally show sculpture similar to that characteristic of P. crassicardo. P. crassicardo is found abundantly in the San Pablo, or upper Miocene forma- tion 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 /. crassicardo associated with the fol- lowing fauna in beds of somewhat uncertain age, in asmall ravine one-half mile south of J. C. Griffin’s ranch house, Priest Valley, Monterey County; P. discus Conrad, Agasoma (aff.) barkerianum Cooper, Mytilus (aff.) mathewsonii Gabb, Venus pertenuis Gabb, and Ostrea titan Conrad. In the Valcito Valley, Fresno County, Mr. H. W. Turner found ?. crassicardo with Venus pertenuis, Dosinia (cf.) ponderosa, and Tellina sp. Mr. Eldridge found P. crassicardo 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 lompocensis, Turritella (cf.) hoffmanni, Phacoides sp. (flat), Ostrea sp., Nassa sp., Dentalium sp., Chione sp., Leda sp., Balanus sp., and Tritoniwm or Fusus sp. Dr. Stephen Bowers has found P. crassicardo with the following species in the Miocene of Laguna Canyon, San Joaquin Hills, Orange County: Pecten estrellanus, Glycymeris 4 sp., Turritella hoffmanni, Chione vn. sp: (large. coarse sculpture), Agasoma kernianum, and Gyrodes ? sp. A beautiful specimen of P. crassicardo in the National Museum (No. 154154) labeled from ‘* California ” is associated in the matrix with Saxidomus gracilis, Tresus nuttalli, and Litorina rémondi. 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 (Pl. XVIII, fig. 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 Costa 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. Dudley for Cal. St. Min. Bureau, Arnold); Quailwater 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) CRAssicarDo Conrad yar. HAMILTONT n. var. Pl. XI, figs. 5 and 6. Description.—Adult shell averaging about 60 millimeters in altitude, sub- equivalve, 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 lamelle; 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. Dimensions.—Al\t. 40 ram.; long. 47 mm.; hinge line about 30 mm.; diameter about 14 mm. This variety is closely allied to the typical P. crassicardo, 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 yalye, and tendency to become more contracted, and consequently more convex when adult or at an altitude of about 60 millimeters. P. var. hameltond resembles P. estre/lanus in size and shape, and in the earlier stages of growth is almost indistinguishable on account of haying but a single line down the middle of the interspace, which resembles the inter- calary riblet of /. estrellanus. 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. hamilton?, 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. estrel- lanus. 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. hamiltond. 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. hamilton? 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. RANGE. Miocene (upper). Alum Rock Canyon, Santa Clara County (Turner; J. P. Smith; Arnold); Mount Hamilton, Santa Clara County (Crawford); Mount Hamilton Range in Alameda County (Yates). Prcren (LYROPECTEN) ESTRELLANUS Conrad. Pl. XIX, figs. 1 and la; Pl. XX, figs. 1, 2, and 2a; Pl. X XI, figs. 1, 1a, 1b, 2; 2a, and 2b. 1856. Palliwm estrellanum Conrad, Pac. R. R. Rept., vol. 6, pt. 2, 1856, p. 71, pl. 3, fig. 15. 1856. Palliwm estrellanum Conrad, Pac. R. R. Rept., vol. 7, pt. 2, 1856; p. 191, pl. 3, figs. 3 and 4. 1857. Palliwm estrellanum Conrad, Proc. Acad. Nat. Sci. Phila., vol. 8 for 1856, p. 313. 1863. Lyropecten estrellanus Conrad, Proc. Acad. Nat. Sci. Phila., vol. 6 for 1862, p. 291. 1863. Lyropecten volaformis 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 PECTENS. US 1888. Liropecten estrellanus 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, pl. 5. figs. 65-67 (text only in part). 1898. Pecten (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 BP caurinus Gould). Description.—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 serrate; 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; inter- spaces each with one sharply outlined, squarish riblet in the middle; surface sculptured by fine raised incremental lirulee which loop back over the ribs and riblets, and, on the anterior and posterior portions of the disk, by radiating striz, which inerease 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 orna- mented by 5 or 6 radiating ridges and more or less prominent incremental lines. Left valve with the ribs narrower and haying 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 incre- mental lirule 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 mm.; 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, 14. 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 deseribed as Lyropecten voleformis by Conrad is the extremely 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 inequivalve, the left valve being the more yentricose. 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 lamellxe over the surface of the valve. The intercalary riblets on this specimen are sharpiy defined. 6 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. Between San Lucas and San Ardo, Monterey County, Mr. Homer Hamlin found a specimen of P. estrellanus 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 grating into var. cataline were found associated at this locality with the typical convex shells. In central California, especially 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 palmula Carpenter and Chorus belcheri Hinds average two or three less. The latter horizon appears to be above that of O. titan. 0 In the region around Coalinga, Fresno County, 2. estrellanus is very common, and is usually associated with Zuméosoma gregaria, Ostrea titan, Venus pertenuis, Chione n. sp. (large; coarse sculpture), Arca canalis, ete., in beds which may be the equivalent of the San Pablo formation. The significance of the total absence of P. estrellanus 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. 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 County (Anderson; Hamlin); Lynch’s Mountain, Monterey County (C. 5. Smith); 15 miles nortb- east 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). Prcten (LYROPECTEN) ESTRELLANUS Conrad var. CATALINA 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 yentricose, 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 or less prominent radial lines; interspaces 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 orna- mented by concentric lines and 5 or 6 rather prominent radiating ridges; poste- rior 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. MIOCENE PECTENS. (ue Dimensions. —Alt. 62 mm.; long. 72 mm.; hinge line 40 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. estrellanus is also lacking in this variety, so far as known. P. var. cataline ranges from the upper Miocene to the Pliocene. On Santa Catalina Island it is associated with the typical P. estrellanus, in beds which are probably upper Miocene, while at Temescal Canyon, near Santa Monica, it is associated with the well-known Pliocene species ?. stearns?7, P. cerrosensis, and Laqueus californicus (ov jeffreysi). 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 (Watts). Miocene (upper). Isthmus, Santa Catalina Island, Los Angeles County (Thurston, Mrs. Trask);? San Ardo and vicinity, Monterey County (Hamlin, Anderson). PECTEN (LYROPECTEN) ESTRELLANUS CONRAD Var. TERMINUS DN. Var. Pl. 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 strongly radially ribbed, the posterior with finer sculpture; byssal notch deep and rather narrow. Left valve similar to right, except that the ribs are relatively narrower. Dimensions.—Alt. 70 mm.; long. 75 mm.; hinge line 43 mm.; diameter 32 mm. This variety is distinguishable from the typical form by its fewer and broader ribs, relatively longer hinge line, and finer obsolete radial striation; and from var. cataline by 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). Prcren (LYROPECTEN) MAGNOLIA Conrad. Pl. XXIV, figs. 1 and 2; Pl. X XV, fig. 1. 1857. Pecten magnolia Conrad, Pac. R. R. Rept., vol. 7, 1857, p. 191, pl. 1, fig. 2. 1888. Liropecten veatchii Cooper (not of Gabb), Seventh Ann. Rept. 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 magnolia Dall, Nautilus, vol. 14, 1901, p. 117 (in part.) bs f (e.2) TERTIARY AND QUATERNARY PECTENS 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; byssal 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.—Al\t. 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 Pecten 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 /ecten, 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. Jeffersonius Say, and is so remark- ably similar to it that it may prove to be the same species when more perfect speci- mens are collected.” The specimens which served as the types for Conrad’s P. magnolia ave in the U. S. National Museum (Nos. 13311 and 13325), 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 species the radiating striz 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. crassicardo, 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: Agasoma barkerianum, Agasoma (cf.) gravida, Agasoma kernianum, Arca (ef.) microdonta, MIOCENE PECTENS. 79 Balanus (cf.) estrellanus, Cardium (Trachycardium) n. sp., Chione mathewsonii, Chione n. sp. (large; coarse sculpture), Crepidula princeps, Cuma biplicata, Dosinia conradi, Dosinia mathewsonit, Dosinia (ef.) montana, Dosinia (aff) ponderosa, Gale- rus (aff.) eccentricus, Glycymeris n. sp. (large), Phacoides ucutilineatus, Phacoides richthofeni, Mytilus mathewsonti, Neverita recluziana, Ostrea (aff.) titan, Panopea generosa, Pecten estrellanus, Pecten (Plagioctenium) andersoni, Solen sicarius, Tivela ineziana, Trochita costellata, Turritella hoffmann 7. 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 mathewsonii, Turritella hoffmann Te Pecten sespeensis var. hyde’, and other lower Miocene forms. : RANGE, 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, 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 mine, San Simeon, San Luis Obispo County (L. Wagner); Ojai Valley, Ventura County (Eldridge). PECTEN (LYROPECTEN) MIGUELENSIS n. sp. Pl. XXII, figs. 1, la, and 1b; Pl. XXII, fig. 1. 1898. Pecten ( Lyropecten) Heermanni Dall, (not Conrad), Trans. Wagner Free Inst. Sci., vol. 3, pl. 4, p. 701. (Specimens in U. 8. Nat. Mus., No. 6397, labeled P. Heermanni by Conrad; Pl. XXIII, 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 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 by several (10 or 11 at extremity of ribs in type) dis- tinct 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 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 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 /% estrellanus. P. miguelensis may be the P. catilliformis of Conrad (Pac. R. R. Rept... Vol. V, Pt. Il, p. 83, Pl. IX, fig: 83) 11857); but his description is so brief and his figure so poor that it is impossible to make anything definite out of it. P. migquelensis is contined to the Miocene (probably lower horizon). The type 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. RANGE. Miocene. San Miguel Island (Univ. of Cal.); Santa Rosa Island (No. 12333, Cal. St. Min. Bureau); Santa Inez Valley, near Santa Barbara (J. H. Wilson); Santa Inez Mountains, near Santa Barbara, Santa Barbara County (Pac. R. R. Expedition). PrcTeN (LYROPECTEN) PERRINI n. sp. PI Xohy;,, fies land ila el exe Ve mtioe al 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 coneaye above. Right valve nearly flat, with about 23 unequal, narrow, more or less rounded, and often prominently imbricated, radiating ribs, which are sometimes dichotomous; interspaces unequal, narrow, and occasionally ornamented by a small auxiliary riblet; surface sculptured by fine incremental lamelle which are much more prominent in some 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 radiating ridges, and concentric sculpture. Left valve quite prominently ventricose, other- wise 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. Dimensions.—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 exactly 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 2. perrini is from 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 PECTENS. $1 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. RANGE. 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 Moun- tains, Kern County (No. 12925, C. S. M. B.) (Watts). PrcrEeN (LLYROPECTEN) VAUGHANI n. sp. Pl. XXIII, figs. 3, 3a, and 3b. Description.—Shell averaging about 40 millimeters in altitude, slightly longer than high, inequivalve, equilateral, convex, and showing constrictions with consequent undulations on the right valve and nodose ribs on the left; base regularly rounded; sides nearly straight above; margins smooth. Right valve with 12 prominent convex ribs separated by concave-bottomed interspaces some- what narrower than the ribs; surface of ribs and interspaces sculptured by numerous fine, imbricated, thread-like, radial lines, between which are fine imbricating concentric lire, 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 lire; byssal notch deep; posterior ear about one-half length of anterior, somewhat concave behind, and ornamented by about 6 radial and numerous fine incremental lire. 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 3 more radials, which are less prominent; posterior ear like that of right. Dimensions.—Alt. 37 mm.; long. 40 mm.; hinge line about 25 mm.; diameter 15 mm. This beautiful little Pecten, though allied to P. magnolia, P. crassicardo, ete., is distinguishable by its small size, obviously unequal ears, long and strongly radially sculptured right anterior ear, deep byssal notch, undulating disk, and finely striated, concave-bottomed interspaces. This form seems to combine the number of ribs of P. magnolia (P. magnolia generally has one to three less), with the sculpture of P. crassicardo var. hamiltoni, the undulations of P. crassi- cardo, and the long, strongly sculptured, right anterior ear of the typical Ch/amys. It appears to be a connecting link between the typical Chlamys and Lyropecten. 17260—No. 47—06——6 82 TERTIARY AND QUATERNARY PECTENS 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. RANGE. Miocene (lower). Ojai Valley, Ventura County (Bowers). PECTEN (PLAGIOCTENIUM) ANDERSONI n. sp. Pl. XXVI, figs. 5, 5a, 6, 7, 8, and 8a. 1894. Pecten discus Cooper (not Conrad), Bull. Cal. St. Min. Bureau, No. 4, pt. 5, 1894, p. 57, pl. 5, figs. 55 and 56 (in part). Description.—Shell averaging about 35 millimeters in altitude, generally some- what longer than high, both valves convex, more or less inequivalve and inequi- lateral; margins smooth; base regularly rounded; sides concaye above. Right valve with 14 to 18 prominent rounded ribs, separated by flat-bottomed inter- spaces, 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 inter- rupted growth; hinge line more than one-half length of disk; ears subequal; anterior ear with 8 or 4 sharp radials and numerous tine 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 about 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. datcauritus and varieties. In fact, the young of 7. andersoni is almost indistinguishable, in some instances, from small specimens of P. latiauritus var. monotimeris. The young of P. andersoni are equilateral, are relatively more convex, and have more prominent ribs than the adult forms. Those specimens of /. 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 7. andersoné 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, ?. discus having 18 to 21. MIOCENE PECTENS. 83 P. andersoni yvanges from the lower to the middle (and probably upper) Miocene. At locality No. 9 (L. 8. J. U. Geol. Survey), on ‘‘Tuff Hill,” 34 miles southeast of Stanford University, 2. anderson? is associated with the following species: Pecten branneri, Chione n. sp., Phacoides acutilineatus, Venus (cf.) pertenuis, Terebratella (%) n. sp., Glycymerts sp., and Balanus sp. (cf.) estrellanus. At locality No. 4, not far from but stratigraphically considerably above No. 9, we find P. andersoni with the the following: Agasoma barkerianum, Arca microdonta, Chione Sp-, Callista vn. sp. A., Dosinia mathewsonii, Leda (cf:) taphria, Phacoides acutilineatus, Mactra californica, Natica ocoyana(*), Saxvidomus gibbosus, Tapes truncata (2), Trochita costellata, Tellina (Angulus) sp., Tritoniuwm sp., Tivela ineziana, and Yoldia n. sp. (aff.) coopert. On the Searsville road, 3$ miles west of Stanford University (locality 2), P. andersoné is associated with the following among other species: Agasoma gravida, Agasoma kernianum, Dosinia. (aff) ponderosa, and Pinna alamedensis. At Barker's ranch, Kern County, Mr. Watts found P. andersoni associated with Agasoma barkerianum and kernianum and other supposedly characteristic lower Miocene forms. 7. anderson’ occurs with P. crassicardo in the upper Miocene 3 miles south of Mount Diablo. In Avenal Canyon, Kern County, 2. anderson? is associated with P. andersoni var. barkerianus, Turritella 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. andersoni, 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 Balanus (ef.) estrellanus. The beds from which the type was taken lie only a few feet below, and conformable with, the base of the characteristic Monterey shales, which are very well developed in the vicinity. RANGE. Miocene (upper). Three miles south of Mount Diablo, Contra Costa County (University of California); Pacheco, Contra Costa County (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 Glenwood (Miss Hecox); near Magnetic Springs; near Felton (locality 32), Santa Cruz County; near Stanford University, at localities 1, 2, 3, 4, 9, 34, and 35, Santa Clara and San Mateo counties (Branner, J. P. Smith, Arnold, and others); Barker ranch, Kern County (Watts); New Almaden (Turner); Contra Costa County (Lawson); near head of Slacks Canyon, NE. 4 sec. 9, T. 22S., R. 18 E., Mount Diablo meridian, Monterey County (Hamlin); Avenal Canyon, Kern County (Eldridge); Devils Den, Kern County (Eldridge). PrcreN (PLAGIOCTENIUM) ANDERSONI var. BARKERIANUS n. var. Pl. XXVI, fig. 9. Description.—Shell averaging about 40 millimeters in altitude, somewhat longer than high, equilateral, somewhat ventricose, and with serrate margins; base regu- $4 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. larly rounded; sides nearly straight, sloping at a moderately low angle. Left valve with 17 rather narrow, prominent rounded ribs, each 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 by radiating ridges and incremental lines. Dimensions.—Alt. 40 mm.; long. 44 mm.; hinge line 28 mm.; diameter 7 mm. This variety, whieh is characterized by the thread-like riblet along the top of each primary rib on the left valye, has been found only in beds of lower Miocene age (ZLurritella ocoyana zone) in the southern San Joaquin country. It is found associated with the following characteristic fauna in the bluffs of the Kern River, | mile below the power-deyelopment station, Kern County: Conus n. sp., Jlactra near planulata, Phacoides sp., Tellina near idx, Trochita pilosa, Agasoma kerni- anum, Agasoma barkerianum, Leda taphria, Leda (aff:) fossa, Cancellaria n. sp., Pleurotoma (Dolichotoma) n. sp., Pleurotoma (Leucosyrina) near pedroana, Chione n. sp. near gnridia, Dentalium 2 n. sp., Nassa (ef.) perpinguis, Pleurotoma sp., Neptunea n. sp., Cructhulum vn. sp., Turritella ocoyana, Cancellaria (cf.) vetusta, Phacoides (cf.) nuttalli, Natica or Lunatia sp., Terebra sp. (probably new), Trophon (cf.) ponderosum, Drillia (aff) torosa, Solen (aff) sicarius. At Avenal Canyon, Kern County, Mr. Eldridge found P. var. barker/anus with P. andersoni, Turritella ocoyana, Dosinia (large and flat), Venus sp., and Ostrea sp. The type of P. var. barkerianus 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-deyelopment station, Kern County (Eldridge). Prcren (PLAGIOCTENTUM) CERROSENSIS GABB var./ MENDENHALLI n. var. Pl. MXXV, figs. 2, 2a, and 26. Description.—Shell, when adult, averaging about 75 millimeters in altitude. Similar to 7. cerrosensis in shape, convexity, and ribbing, but differing from the latter in being 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. Dimensions (of a medium-sized specimen).—Alt. 43 mm.; long. 44 mm.; hinge line 28 mm.; diameter 17 mm. Although this form is closely allied to P. cerrosensis, it, nevertheless, should possibly have specific rank, as the differences between it and the typical DP. cervosensis 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 MIOCENE PECTENS. 85 of California from Guaymas, Mexico. At the type locality it is associated with the following fauna: Pecten carrizoens/s, Pecten keepi, Cardium sp., Chione uv. sp., Glycymeris sp., Ostrea sp. (large), Codakia sp. (very large), Semele (aff.) pulchra, Cardita (Carditamera) sp., Strombus sp., Malea (aff-) ringens, echinoid, spines, ete. The type of P. var. mendenhalli is U. S. N. M. No. 164849, 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. RANGE. Miocene. Santa Rosalia, Lower California ({7. P. Merrill; E. Palmer); head of Garnet Canyon, about 12 miles north of the Mexican boundary, and Alverson Canyon, about 8 miles north of the Mexican boundary, San Diego County (W. C. Mendenhall; 5. Bowers). PrcrEN (PLAGIOCTENIUM) DESERTI Conrad. PIP XOX VI, figs.-15°2, 20,3; 4, and 4a. 1855. Pecten deserti Conrad, Desc. Fos. and Shells., House Doc., 129, July, 1855, p. 15 (fide Dall). 1856. Pecten deserti Conrad, Pac. R. R. Rept., vol. 5, 1856, p. 325, pl. 5, fig. 41. 1888. Pecten deserti Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., for 1887, p. 257. 1894. Pecten (Plagioctenium) deserti Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 703. Description.—Shell averaging about 32 millimeters in altitude, about as long as high, biconvex, equivalve, subequilateral, and with serrate 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; byssal 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. Dimensions.—Alt. 32 mm.; long. 33 mm.; hinge line 25 mm.; diameter 17 mm. This species is distinguishable from allied forms by its strong hinge, tall, narrow, close-set ridges and straight incremental sculpture in the bottoms of the interspaces. P. deserti has so far been found only in beds supposed to be of Miocene age, in the Carrizo Creek district, Colorado Desert, San Diego County. From the evidence at hand it seems likely that P. deserti occupies a somewhat different horizon (possibly lower) than that containing P. carrizoensis, P. keepi, and P. cerrosensis var. mendenhalli. RANGE. Miocene. East end of Carrizo Mountain, and Ulsa oil well, north of the Mexican boundary, San Diego County (Conrad; Fairbanks; Bowers; Mendenhall). [o 0) or) TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. Prorpn (PLAGIocTENIUM) Discus Conrad. Pl. XXVII, figs. 1, la, 2, 3, and 4. 1857. Pecten discus Conrad, Pae. R. R. Rept., vol. 7, pt. 2, 1857, p. 190, pl. 3, fig. 1. 1869. Pecten discus Conrad, Gabb, Pal. Cal., vol. 2, 1869, p. 122. 1888. Pecten discus Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 257. 1888. Pecten pabluensis Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 258 (in part). 1894. Not Pecten discus Cooper, Bull. Cal. St. Min. Bureau, No. 4, pt. 5, 1894, p. 57, pl. 5, figs. 55, 56. . : (= P. andersoni n. sp.) 1898. Pecten (Chlamys?) discus Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 704. Description.—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 valye with 17 to 20 moderately 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 indurated clay, is characterized by its moderately strong, convex ribs, compressed disk, and strikingly unequal ears on the right valve. Specimens of 7. discus haying 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 7”. pabloens/s and seems to represent the latter in what is probably the equivalent of the San Pablo (upper Miocene) forma- tion 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: Ocinebra near cancellina, Trochita jilosa, Mytilus mathewsonii (%), Arca sp. indet., and Voluta (4) 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. Moran); Huasua ranch, 20 miles, north of Santa Maria, Santa Barbara County (C. E. Knecht). MIOCENE PECTENS. 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). PrcrEN (PLAGIOCTENIUM) ELDRIDGEI n. Sp. Pl. XXV, figs. 3, 3a, 3b, 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 heavy, 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 ribs, 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 orna- mented by 3 or + prominent radiating ridges and numerous imbricating incre- mental 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. Dimensions.—Alt. 20 mm.; long. 21 mm.; hinge line 15 mm.; diameter 15 mm. This species is similar in many respects to P. circularis, 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 45 millimeters, as shown by fragments collected at the type locality. P. eldridgei appears to be confined to the oil-bearing strata of the San Joaquin Valley, which are 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 Dabney water wells, McKittrick district, Kern County. Named in honor of the late Mr. G. H. Eldridge, of the United States Geological Survey. RANGE, Miocene (upper). McKittrick district, Kern County (Eldridge); Buena Vista and McKittrick, Kern County (Watts). PrctEN (PLAGIOCTENIUM) NEAHENSIS 0. sp. Pl. XV, figs. 2, 2a and 20. Description. —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 PECTENS OF CALIFORNIA. interspaces; surface sculptured by fine incremental lirulee 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 conyex above and the interspaces relatively broader; ears as in right valve. Dimensions.—Alt. 48 mm.; long. 50 mm.; hinge line 28 mm.; diameter 28 mm. This species is probably allied to P. cireularis and P. cércularis var. equisulcatus, 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. neahensis, 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 (7) Neah Bay, Washington (J. G. Swan). Prcren (PLAGIOCTENIUM) PABLOENSIS Conrad. Pl. XX VII, figs. 5, 5a, 6, 6a, and 7. 1857. Pecten pabloensis Conrad, Pac. R. R. Rept., vol. 6, pt. 2, 1857, p. 71, pl. 3, fig. 14. 1888. Pecten pabloensis Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 258 (in part). io 2) es 1898. Pecten (? Plagiocteniwm) pabloensis Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 703. Description.—Shell averaging about 35 millimeters in altitude, about as high as long, equivalve, equilateral, thin, only slightly ventricose, and with smooth margins; sides sloping at a low angle and quite prominently concave above. Right 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 fine 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. c¢rcwlaris except that the cardinal crura are very faint, while the auricular crura are quite prominent. MIOCENE PEOCTENS. 39 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 type 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 very much resembled a young P. cércularis var. «equisulcatus. P. pabloensis is so far known only in the San Pablo, or upper Miocene formation. At the type locality, on the shore of San Pablo Bay, Contra Costa County, a bed several feet thick is made up almost entirely of valves of this species. At this locality P. pabloensis is associated with P. crassicardo and P. andersoni (4). RANGE. Miocene (upper). Shores of San Pablo Bay, Contra Costa County (Newberry; Merriam; Arnold). PECTEN (PSEUDAMUSIUM) LOMPICOENSIS n. sp. Pl. XXII, fig: 5; Pl. XX VI, fig. 8: Description.—Adult shell averaging about 11 millimeters in altitude, subcir- cular, inequivalve, thin, compressed; margins smooth. Right valve ornamented externally by numerous sharp, elevated, equal, equidistant, imbricating, concentric lamelle; 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 lamelle and 6 or 7 faint radials; posterior ear short, somewhat obliquely truncated and sculptured by concentric lamelle; byssal notch only faintly indicated. Left valve sculptured by concentric lamelle similar to those of the right, and, in addition, having numerous fine radiating strive, 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 radials were noted on the anterior one. Hinge similar to that of 2. randolphi. Dimensions (of slightly distorted specimen).—Al\t. 11.5 mm.; long. 11 mm.; hinge line 5.5 mm. This beantiful little Pecten is allied to P. peckhami, but is distinguishable from the latter by its much more prominent and regular concentric lamelle, 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. pechham/. The byssal notch in P. lompicoensis is also only faintly indicated, while in 7. peckhami the notch is profoundly developed. P. lompicoensis 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 Phacoides resembling acutilineatus Conrad. RANGE. Miocene. Head of Lompico Creek, Santa Cruz County (Newsom, Arnold). 90 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. PrEcTEN (PSEUDAMUSIUM) PEDROANUS Trask. Pl. XXVIII, figs. 4 and 5. 1856. Plagiostoma Pedroana Trask, Proc. Cal. Acad. Nat. Sci., vol. 1, 1856, p. 93, pl. 3, figs. 1, la. 1856. Plagiostoma truncata Trask, Proc, Cal. Acad. Nat. Sei., vol. 1, 1856, p. 94, pl. 3, fig. 3. 1856. Plagiostoma annulatus Trask, Proc. Cal. Acad. Nat. Sci., vol. 1, 1856, p. 94, pl. 3, fig. 2. 1869. Pecten Pedroanus Trask, Gabb, Pal. Cal., vol. 2, 1869, p. 60. 1888. Peeten pedroanus Trask, Cooper, Seventh Ann. Rept. Cal. St. Min., for 1887, p. 258. 1898. Pecten pedroanus Trask, Dall, Trans. Wagner Free Inst. Sci., vol.'3, pt. 4, 1898, p. 705. The original description is as follows: Description.—* Shell compressed, subtriangular, with 8 or 9 flatly rounded concentric annulations, which are nearly as distinctly marked on the interior of the valve for about half the height from the ventral margin; beaks acute at the apex, 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 18 small, rounded, radiating strie, which converge at the beak; beaks at the anterior third; subacute; anterior margin rounded, and somewhat produced; ventral margin smoothly arched; posterior margin rounded, becoming slightly arcuate toward the dorsum, of the shell; posterior auricle angulate and obtusely truncate posteriorly.” Dimensions.—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 1856 Doctor Trask named three species of //agiostoma, giving full descriptions and well-executed figures as above. His specimens are casts of a number of distorted Pectens, perhaps normally a little oblique, but in most cases with the obliquity exaggerated by pressure. They belong without question to but one species, and the first name given will have to be retained. I have carefully studied the specimens, and have visited the locality from which they were obtained. 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 normally 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. 164840). In several of these specimens the original shell material is quite well preserved, and in one case Camptonectes aPal. Cal., vol. 2, 1869, p. 60. MIOCENE PECTENS. 91 sculpture of numerous faint radiating ribs, microscopic striz, and numerous more or less prominent lines of interrupted growth were plainly seen. The sculpture was very similar, if not identical, to that of 2. randolphi. P. pedroanus and P. randolphi ave also alike in shape and general characteristics, and the only difference noted in a comparison of the two was the slightly larger size and more prominently 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 P. pedroanus the following fauna: Pecten ashleyi, P.'stearnsii, P. opuntia, Glyphis densiclathrata, Pecten latiauritus, Nassa n. sp.?, Macoma sp. indet., Arca multi- costata, Lima hamlini, Buccinum sp. wdet., Neverita recluziana, Astarte? sp.. Priene oregonensis, Ostrea veatehii, Pleurotoma sp. indet., carditoid, coral, bird bone, and crab claw. This fauna indicates a horizon about the same as that of the San Diego formation, and is Pliocene (probably lower) in age. It therefore seems likely that P. pedroanus, 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. randolphi. RANGE. 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); + miles south of McKittrick, Kern County (Eldridge). PrCcTEN (PROPEAMUSIUM) STANFORDENSIS nN. sp. Pl. XXIII, fig. 4. Description.—Shell averaging about 9 millimeters in altitude, subcireular, equivalve, equilateral, thin, only slightly ventricose, and with smooth margins. Right valve with the exterior surface ornamented by numerous fine concentric undulations and, in some cases, microscopic radiating strive; interior with 10 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 slightly 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. Dimensions. —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 some- times 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. interradiatus of the Tejon (Eocene), but may be distinguished from it by having 10 to 12 instead of § ribs, being 92 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. smaller, and haying the ribs reach to or nearly to the periphery rather than abruptly terminating near the middle of the disk. The type specimen, which is the one figured, is now in the collection of Delos Arnold. It is from the buff-colored Miocene shale in a small ravine on the Burke ranch, one-third mile south of Los Trancos Creek, near Stanford University, San Mateo. County. This species is named in honor of Leland Stanford Junior University. So far this species has been found only in the type locality, where it is associated with Pecten pedroanus (%) and several small undetermined pelecypods. Its range, as determined stratigraphically, is probably middle Miocene or Monterey. Its associated fauna also adds weight to this theory. RANGE. Miocene (middle). Burke ranch, 3 miles south of Stanford University (Branner, J. P. Smith, R. Arnold). : PrcreN (AMUSIUM) LOMPOCENSIS n. Sp. Pl. XXVIII, figs: 1, 2; and 3: Description. —Adult shell averaging about 100 millimeters in altitude, somewhat longer than high, compressed, subequivalve, equilateral, and thin; base regularly rounded; sides straight, or nearly so; margins smooth. Right valve with external surface smooth except for vei fine and numerous concentric and nearly obsolete radiating strie; internal surface sculptured by about fourteen pairs of rather prominent rounded radiating lire, the members of each pair being separated by flat spaces usually of about two-thirds the width of the major interspaces (in one case the spaces between the members of each pair were as wide as the interspaces); hinge line about two-fifths the length of the disk; ears subequal, obliquely truncated, and finely concentrically sculptured; anterior with a faint suggestion of a byssal notch; ctenolium absent. Left valve similar in all respects to the right except that the anterior ear has a straight, rather than an arcuate end. Dimensions.—Al\t. 103 mm.; long. 113 mm.; hinge line 40 mm.; diameter 20 mm. This very unique species, of which there are no closely allied forms in the Tertiary or living faunas of the west coast, so far as known, is somewhat analogous to P. (Amusium) mortoni Ravenel of the Miocene and Pliocene of eastern America. It is distinguishable from the latter species, however, by the smaller number, greater prominence, and more regular arrangement of the internal ribs. P. lompocens/s is included in Amusiwm because it appears to show stronger affinities for this than for any other group. P. lompocensis was first discovered in the limy beds which outcrop about 4 miles south of Lompoc, Santa Barbara County, where the types, which are now in the collection of the California Academy of Sciences, were collected by Mr. Frank M. Anderson. At the type locality this unique form is found associated with the following species in beds of probable lower Miocene age: Pecten crassicardo, Ostrea (aff.) titan, Lima n. sp., Cidaris (2) sp., Terebratella 2 sp., and Scutella MIOCENE PECTENS. : 93 sp. On the ridge between the Upper and Lower Ojai Valleys, Ventura County, Mr. Eldridge has found P. lompocensis with the following species, in beds which he thinks are of lower Miocene (Vaqueros) age: Pecten crassicardo, Turritella (cf.) hoffmanni, Phacoides sp. (flat), Ostrea sp., Nassa sp., Dentalium sp., Chione sp., Leda sp. Balanus sp., Tritonium or Fusus sp. RANGE. Miocene (lower ?). Four miles south of Lompoc, Santa Barbara County (F. M. Anderson); ridge between upper and lower Ojai valleys, Ventura County (Eldridge). . Prcren (HINNITES) GIGANTEUS Gray. Pl. X XIX, figs. 1, 2, and 2.a 1826. Hinnites giganteus Gray, Ann. Phil., 2d ser., vol. 12, 1826, p. 103. 1834. Hinnita poulsoni Conrad, Jour. Acad. Nat. Sci., Phila., vol. 7, p. 182, pl. 14. 1843. Hinnites giganteus Gray, Sowerby, Thes. Conch., vol. 1, Hinnites, p. 80, pl. 20, figs. 3-5. 1853. Hinnites giganteus Gray, Reeve, Conch. Icon., vol. 8, Hinnites, Oct., 1853, sp. 2, pl. 1, fig. 3. 1857. Hinnites crassa Conrad, Pac. R. R. Rept., vol. 7, pt. 2, p. 190, pl. 2, figs. 1 and 2. 1863. Hinnites giganteus Gray, Carpenter, Brit. Assn. Rept., 1863, p. 645. 1863. Hinnites crassa Conrad, Carpenter, Brit. Assn. Rept., 1863, p. 595. 1869. Hinnites giganteus Gray, Gabb, Pal. Cal., vol. 2, 1869, p. 105. 1887. Hinnites giganteus Gray, Whiteaves, Trans. Roy. Soe. Canada, vol. 4, sec. 4, 1887, p. 119. 1888. Pecten (Hinnites) giganteus Gray, Kuster, and Kobelt, Gonch.-Cab., vol. 17, pt. 2, Spondylus und Pecten, sp. 228, taf. 65, figs. 9 and 10. 1888. Hinnites giganteus Gray, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 243 (Santa Rosa Island record excepted). 1892. Hinnites g iganteus Gray, Keep, West Coast Shells, p. 165, fig. 138. 1892. Hinnites giganteus Gray, Williamson, Proc. U. 8. Nat. Mus., vol. 15, 1892, p. 193. 1898. Hinnites giganteus Gray, Dall, Trans. Wagner Free Inst. Sci.. vol. 3, pt. 4, 1898, p. 711. 1898. Hinnites crassa Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, p. 711. 1903. Pecten ( Hinnites) giganteus Gray, Arnold, Mem. Cal. Acad. Sei., vol. 3, pt. 2, 1903, p. 115. 1904. Pecten (Hinnites) giganteus Gray, Keep, West American Shells, p. 42, fig. 22. Description.—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, between which in the flat interspaces are less prominent raised lines similarly sculptured; hinge line more than one-half length of disk; ears subequal, and more or less prominently sculptured by fine, squamose, radiating lines; byssal 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. Dimensions. —Alt. 70 mm.; long. 65 mm.; hinge line 40 mm. in length, 10 mm. in width; diameter 35 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 case, 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. hastatus and yarieties, except possibly that the ribs on the right valve of //inn7tes are rather more irregular in size than those of Chlamys. After comparing Conrad’s types of ///nnites crassa with a large series of living Hinnites giganteus, the writer has no hesitation in pronouncing the two species identical. The types of //. crassa were collected from the upper Miocene near Santa Margarita. (See Pl. X XIX, fig. 1.) P. (Hinnites) giganteus ranges from the lower Miocene to the living fauna. Mr. Eldridge found it associated with Zurritella hoffmanni in a small gulch east of Wiley Canyon, Ventura County. RANGE. Living. Strait of Fuea 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). 5 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 first to appear in the Pliocene formations.] PrcTEN (PECTEN) AUBURYI n. sp. Pl. XX XIII, figs. 2 and 2a; Pl. 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 by 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, fine, 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 /. leconted, 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. auburyi has so far been found only in beds of probable lower Pliocene age. About 1 mile east of the Chandler wells. Puente Hills, Los Angeles County, it is PLIOCENE PECTENS. 95 associated, according to Doctor Merriam (see Merriam, 1900, p. 222), with Cancellaria 2n. sp., Crepidula sp. indet., Drillia sp., Hinnites near giganteus, Natica (Neverita (aff.) recluziana, Priene(aff.) oregonensis, Ranella californica, and Trochita sp. indet. At Olinda, Puente Hills, Orange County, Mr. Eldridge found P. auburyi with the following lower Pliocene fauna: Pecten ashleyi, P. wattsi, P. oweni, var., Priene (aff.) oregonensis, Cardium (cf.) quadrigenarium, Neverita recluziana, Phacoides californicus, FBusus (cf.) barbarensis, Arca maulticostata (4), Nassa perpinguis (2), Chione sp., Leda taphria, Fissuridea murina, Nassa fossata, Phacoides richthofeni, Phacoides nuttalli, Phacoides (cf.) acutilineatus, Cardium (cf) corbis, Chione sp., Dentalium neohexagonum, Solen (cf.) sicarius, Turritela cooperi, Crepidula rugosa, Astyris sp., Cancellaria nu. sp., Calliostoima costatum, Modiolus (ef.) rectus, Bulla punctulata, and Dentalium n. sp. (like Miocene form). The type specimen is from the first-mentioned locality, and is now in the State Mining Bureau. Named in honor of Mr. Lewis E. Aubury, State Mineralogist of California, through whom the writer was enabled to procure the valuable Pecten material in the State museum. RANGE. Pliocene. Locality 38, 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). Prcren (PECTEN) BELLUs Conrad. Pl. XX XI, figs. 1 and la. 1857. Janira bella Conrad, Proc. Acad. Nat. Sci. Phila., for 1856, p. 312. 1857. Janira bella Conrad, Pac. R. R. Rept., vol. 6, 1857, p. 71, pl. 3, fig. 16. 1869. Janira bella Conrad, Gabb, Pal. Cal., vol. 2, 1869, p. 105, pl. 16, fig. 20. 1888. Janira bella Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 244. 1898. Pecten ( Pecten) bellus Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 704; not P. bellis McCoy (teste Dall, 1898). 1900. Vola sp. indet., Merriam, Bull. Cal. St. Min. Bureau, No. 19, 1900, p. 222, table ITI. 1903. Pecten ( Pecten) bellus Conrad, Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 103, pl. 21, figs. 1, 2. Description.—Shell large, thin, inequivalve, elegantly, radiately ribbed. Left (upper) valve slightly convex, the point of greatest convexity being 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 by 13 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, with slightly rounded bottoms; whole surface of left disk covered with fine, sharp, concentric, regular lamelle; ears rather small, subequal, slightly concave, finely concentrically lamel- lated, separated from the disk by an impressed line. Right (lower) valve promi- nently convex, the point of greatest convexity being about one-third the distance from the apex to the ventral margin of the disk; the umbo in this valve curves sharply and meets the plane of the ears at an angle of about 90 degrees; surface 96 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. of right yalve ornamented by 14 or 15 prominent, nearly flat-topped, square, radia- ting ribs, some of them with one or two longitudinal obsolete lines; the ribs become somewhat less 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 lamellee; byssal notch small. Dimensions.—Alt. 80 mm.; lat. 108 mm.; diam. 32 mm.; length of hinge line, 45 mm. The description, measurements, and figures are of Gabb’s type specimen of Junira bala (No. 960, Collection Academy Natural Sciences, Philadelphia), which was kindly lent to the writer by Prof. H. A. Pilsbry, curator of Mollusca. P. stearnsii and P. diegensis are distinguishable from P. be/lus by the more numerous (25 or 28 in the first, 20 or 22 in the second), narrower, sharper defined, perpendicular-sided, radiating ribs on the right valve, and by the evenly rounded, prominently and evenly lamellated ribs of the left valve. 2. hempAcll7. is distin- euishable from P. bellus by its smaller size; by haying on the right valve more numerous (15 or 16 in the former), round-topped, narrower, nearly perpendicular- sided, 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. hemphilli 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 speci- mens of P. bellus. P. excavatus is distinguishable from P. be//us by its smaller size, greater convexity of right valve, greater concavity of left valve, greater number of ribs, and by the auxiliary ribs in the left valve. After a careful comparison of a large series of 7. bel/ws with Conrad’s deserip- 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 are different. This idea was probably caused by the exaggeration of the bicarination of the ribs in Conrad's figure. Several of the specimens of 7. be//us examined by the writer show this bicarination to a greater or less degree, although as a rule the ribs are nearly smooth-topped. A large series of P. be/lus and P. hemphilli show the differences enumerated in a previous paragraph to be constant for the adults. The young of both species up to an altitude of 20 millimeters are nearly identical in appearance, P. bellus, so far as known, is confined to the Pliocene. It occurs abundantly in the Pliocene formation on Packards Hill, Santa Barbara, and in other localities in the vicinity. The type was obtained near Santa Barbara. RANGE. Fliocene. Santa Barbara (Conrad; Gabb; Yates; Cooper; Arnold); Top of hill, Long Tom mine, Kern County (Watts); Eureka Canyon, west side, near mouth, Ventura County (Eldridge); Rincon asphalt mine, Santa Barbara County (Watts); Loc. 33, east side of Piru Creek, near railroad bridge, Ventura County (Watts); ? Temescal Canyon, north of Santa Monica, Los Angeles County (Rivers). PLIOCENE PECTENS. 97 PECTEN (PECTEN) COALINGAENSIS n. sp. Pl. IV, figs. 4, 4a, and 5. Description.—Shell about 45 millimeters in altitude, longer than high, plano- convex, or nearly so, equilateral, and with smooth margins. Right valve ventricose and ornamented by about 20 ribs which have narrow, somewhat convex tops, and sides which slope at angles of about 45°; 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 by 2 or 3 obsolete radiating ridges and numerous fine incremental lines. Left valve flat, with 19 prominent convex ribs, a surface sculpture of fine regular incremental lines, and concave ears which are slightly obliquely truncated. Dimensions. —Alt. 45 mm.; long. 52 mm.; hinge line 28 mm.; diameter 18 mm. This species is easily distinguishable by the 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. RANGE. Pliocene (lower). Coalinga, Fresno County (li. D. O'Neal); Kreyenhagen’s ranch, Fresno County (Watts, Anderson, Arnold). PrecreN (PEcTEN) HEMPHILL Dall. Pl. XX XIII, figs. 3, 3a, and 3b. 1879. Pecten hemphilli Dall, Proc. U. 8. Nat. Mus., vol. 1, 1879, p. 15. 1888. Pecten hemphilli Dall, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 257. 1898. Pecten ( Pecten) hemphilli Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 706. 1903. Pecten ( Pecten) hemphilli Dall, Arnold, Mem. Cal. Acad. Sei., vol. 3, 1903, p. 105. Description.—Shell of medium size, thin, inequivalve. Upper (left) valve flat or slightly concave, with a concave depression between middle of valve and umbo; surface of this valve sculptured by 16 or 17 very prominent, rather narrow radiating ribs, which are nearly flat-topped and have nearly perpendicular sides; interspaces wider than ribs, with rounding bottoms; fine incremental lamellz cover the surface of this valve; ears square-cornered and concave, covered with incremental lamelle. Lower (right) valve convex, the convexity being most apparent between middle of valve and umbo; sculptured by 16 prominent squarish ribs, which are similar to those on the upper valve, except 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 except convex, the right one having 3 or 4 radiating ridges and a small byssal notch. 17260—No. 47—06——7 98 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA, Dimensions. —Alt. 56 mm.; long. 63 mm.; diam, 15 mm.; hinge line 28 mm. This species is readily distinguishable from /. stearnsii and P. diegensis by its smaller size, greater convexity of lower valye, and fewer ribs. Distinguishable from P. bellus 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. RANGE, Pliocene. Temescal Canyon, north of Santa Monica, Los Angeles County (Rivers); Pacific Beach, Russ School, and ‘*San Diego well,” San Diego (Hemphill, Dall, Arnold). Prcren (PECTEN) LECONTEI n. sp. Pl. XX NIII, figs. 4, 4a, and 4b. 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 by 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 3 broad, nearly obsolete, radiating ridges, imbricating incremental lines, and a rather small byssal notch; the posterior rectangularly truncated, and with fine incremental sculpture. Left valve flat or slightly concave, ornamented by about 17 prominent rounded ribs, which are separated by inter- spaces about equal in width to the ribs; surface sculptured by numerous fine, sharp, regular, raised, incremental lines; ears concave, rectangularly truncated, and covered by fine sharp incremental lines. Dimensions.—-Alt. 59 mm.; long. 65 mm.; hinge line 29 mm.; diameter 18 mm.; umbonal angle (left valve) 102°. This species is distinguishable from P. diegensis, P. bellus, P. stearnsii and other members of this group by the number and convexity of the ribs on the right valve. The left valves of P. /econted and P. diegensis are somewhat similar, although the former has fewer ribs and is generally slightly more concave. P. lecontci has so far been found only in the Pliocene of Cerros Island, where it is associated with P. veatchii, P. cerrosensis, and Ostrea veatchii. 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. RANGE, Pliocene. Cerros Island, Lower California (University of California). PLIOCENE PECTENS. Shy) PrCTEN (PECTEN) MERRIAMI Nn. Sp. Pl. XXX, figs; 1, la, and 2. 1900, Pecten meekii Merriam (not of Conrad, 1857=P. caurinus Gould), Bull. Cal. St. Min. Bureau, No. 19, 1900, p. 222. Description.—Shell averaging about 115 millimeters in altitude, longer than high, inequivalve, equilateral, of medium thickness, and with smooth margins; base evenly rounded; sides straight or only slightly concave above, sloping at a rather low angle. Right valve decidedly ventricose, with 18 or 19 subequal, strong, square ribs, some of which show faint medial sulcations near their extremities; interspaces flat-bottomed and somewhat narrower than ribs: whole surface of disk sculptured by more or less prominent lines of growth; hinge line more than one-half length of shell; ears about equal in length; anterior ear with faint byssal notch, obsolete radiating ridges and fine incremental sculpture; pos- terior ear rectangularly truncated, and with faint radial and fine concentric sculpture. Left valve flat to concave, with a more or less prominent bulge just below the umbo, as in 7. del/us; ribs prominent and rounaed, relatively flatter and broader as the periphery of the disk is approached; interspaces about as wide as the ribs, round-bottomed, and some of them showing a faint intercalary riblet; surface sculptured by fine, sharp, looped, concentric lines: ears ornamented by 5 or 6 rather prominent radiating ridges and numerous fine concentric lines. Dimensions.—Alt. 115 mm.; long. 180 mm.; hinge line 70 mm.; diameter 30 mm. P. merriamé is distinguishable from . bellus, to which it is allied, by its much larger size when adult, more numerous ribs (18 to 19 in the former, 14 to 15 in the latter), relatively longer hinge line (the hinge line of the former being about 60 per cent of the length of the disk, while that of the latter is only about 45 per cent), and the radial ridging of the ears. The types of this species, which are the only specimens of it so far known, were collected by Mr. Watts from light-colored shale underlying the conglomerate on San Felician Creek, near Piru, Ventura County. The following fauna, as given by Doctor Merriam,“ was associated with P. merriam? at the type locality: Echinarachnius near E@CENTPLCUS, Macoma near sectd, Nassa sp. indet., Pachypoma n. sp.. Solen sécarius, and, as determined by the writer, Pecten cerrosensis. This fauna indicates beds of probable lower Pliocene age. The type of P. merriaimné is now in the collection of the California State Mining Bureau, San Francisco. Named in honor of Dr. John C. Merriam, professor of paleontology, Uni- versity of California, to whom paleontologists are indebted for so much of their knowledge regarding the faunas of the California Tertiary. RANGE. Pliocene (lower). San Felician Creek, near Piru, Ventura County (Watts). aBull. Ca). St. Min. Bureau, No. 19, 1900, pp. 220-222. 100 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. Prcren (Prcren) stearnsit Dall, Pix NOT hess itandiia: 1869. Janira dentata Gabb (not Sowerby), Pal. Cal., vol. 2, 1869, p. 104 (in part). 1879. Pecten stearnsii Dall, Proc. U. 8. Nat. Mus., vol. 1, 1879, p. 14. 1888. Janira dentata Cooper (not Sowerby), Seventh Ann. Rept. Cal. St. Min., 1888, p. 244 (in part). 1898. Pecten ( Pecten stearnsii Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 706, pl. 26, fig. 5. 1900. Vola sp. indet., Merriam, Bull. Cal. St. Min. Bureau, No. 19, 1900, p. 222, table 4. 1903. Pecten (Pecten) stearnsii Dall, Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 106, pl. 12, fig. 3. Description.—Shell of medium size, subcireular, inequivalve, concayo-convex, thin; right valve slightly convex, with about 26 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 covered with concentric lamelle which are much finer 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, sharp, concentric, regular lamellae, a little looped backward over the tops of the ridge; ears of this valve concave, with obsolete radiating ridges, and fine, con- centric lamelle; ears of right valve subequal, arched, covered with crowded, elevated lamellae; byssal notch very small. Dimensions.—Alt. 62 mm.; long. 71 mm.; diameter 14 mm.; hinge 25 mm. According to Doctor Dall this is the precursor of 2. déegens/s, from which it differs by having 5 or 6 more ribs, which in the adult have a conspicuous medial suleus. P. stearnsii, so far as known, is contined to the Pliocene. It is quite abundant at Pacifie Beach, near San Diego, where it is associated with 2. healey/, P. hemp- hilli, Opalia waricostata, O. anomala, Scala stearnsii, Pecten parmelee?, and other unique forms. Ina well at San Juan Capistrano it was found by Watts associated with Zurritella cooper’, Venericardia ventricosa, Arca trilineata, Nassa mendica, ete. Two left valves have been found in the Pliocene at Deadman ‘Island, near San Pedro. RANGE, Pliocene. Temescal Canyon, Santa Monica Mountains, Los Angeles County (Watts, Rivers); San Pedro (Arnold); San Juan Capistrano, Orange County (Watts); Pacific Beach, near San Diego (Hemphill, Stearns, Dall, Arnold); Third street tunnel, Los Angeles (Hamlin). Prcren (PECTEN) VOGDESI n. sp. Pl. XMM, figs. 1 and la; Pl. XXXIV, fig: 1- 1888. Janira dentata Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 244 (Quaternary records). 1903. Pecten (Pecten) dentatus Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 105 (Pleistocene record). Description.—Shell similar to P. excavatus, except averaging larger and with the following differences: Right valve, somewhat less convex, has 19 or 20 broader, flatter ribs, which are separated by relatively broader interspaces that occasionally show faint intercalary riblets or faint longitudinal striations. Left valve with fewer ribs PLIOCENE PECTENS. 101 than P. excavatus, and having no intercalary riblets, or else faint ones, which become obsolete near the periphery of the disk; ears slightly less coneaye than in P. arcavutus. Dimensions.—Alt. 69 mm.; hinge line to ventral margin (right valve) 67 mm.; long. 73 mm.; hinge line 35 mm.; diameter 24 mm.; umbonal angle (left valve) 98°. All of the Pleistocene specimens of the group of which 7. ercavatus is the living representative have the constant differential characteristics above enumerated. 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 Sciences from the Pleistocene of Ventura County 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 County, is now in the collection of the California Academy of Sciences. 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. Army. RANGE. Pleistocene. San Pedro (Arnold); Ventura County (Bowers); San Diego (Hemphill). Pliocene (#7). San Diego (Hemphill); Cholas Valley, near San Diego (Stearns). PrcrEen (PATINOPECTEN) CAURINUS Gould. Ply XXEX VIO, figs: J, Wa; and! 1b) Ply XOXOXMEXS figs: 1) and’ 2. Pecten caurinus Gould, Proc. Bost. Soc. Nat. Hist., vol. 3, 1850, p. 345. Pecten caurinus Gould, Wilkes Expl. Exped., vol. 12, p. 458, figs. 569, 569a, 5695. 1855. Pecten Heermanni Conrad, Proce. Acad. Nat. Sci. Phila., vol. 7, 1855, p. 267 (not P. (Lyropecten) Heermanni Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 701, nor Pecten Heermanni Dall, Nautilus, vol. 14, 1901, p. 117, = P. estrellanus Conrad). 7. Peeten Meekii Conrad, Proc. Acad. Nat. Sci. Phila., for 1856, Ist ser., vol. 8, 1857, p. 313. 1857. Pecten Meekii Conrad, Pac. R. R. Rept., vol. 7, pt. 2, 1857, p. 190, pl. 1, fig. 1 1863. Amusium caurinum Gould, Carpenter, Brit: Assn. Rept., 1863, p. 645. 1863. Pecten Yessoensis Carpenter, loc. cit., p. 645 (not P. Yessoensis Jay, Perry’s Voyage, 1856); — P. propatulus Carpenter, loc. cit., p. 679 (not Conrad, 1849). Fide Dall, 1898. 1886. Not Pecten cawrinus Dall, Bull. Mus. Comp. Zool., vol. 12, p. 216, pl. 5, fig. 4, 1886 (= P. vancouverensis Whiteaves ). 1888. Pecten caurinus Gould, Kuster and Kobelt, Conch.-Cab., vol. 17, pt. 2, Spondylus und Pecten, sp. 108, p. 152, taf. 43, fig. 1. 1888. Amusium caurinus Gould, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 228 (excepting “Japan’’). 1888. Pecten propatulus Cooper, loc. cit., p. 258 (‘Eel River, Humboldt County’’). 1889. Not Pecten caurinus Dall, Bull. U. 8. Nat. Mus., no. 37, 1889, pl. 5, fig. 4 (=P. vancouverensis Whiteaves) . 1892. Pecten caurinus Gould, Williamson, Proc. U. 8. Nat. Mus., vol. 15, 1892, p. 193. 1892. Amusiwm caurinum Gould, Keep, West Coast Shells, 1892, p. 168. 1898. Pecten (Patinopecten) caurinus Gould, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p- 710. 1903. Pecten (Patinopecten) cauwrinus Gould, Arnold, Mem. Cal. Aead. Sci., vol. 3, 1903, p. 107, pl. 13, fig. 6. 1903. Not Pecten cawrinus Dall, Bull. U. 8. Nat. Mus., no. 37 (reprint), pl. 5, fig. 4, 1903 (=P. vancouverensis Whiteaves). 1904. Pecten caurinus Gould, Keep, West. Am. Shells, pp. 38-39. 102 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. Description.—Shell averaging 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 strie; interspaces flat-bottomed and about. equal in width to the ribs; whole surface of disk sculptured by fine incremental lines; hinge line less than one- half length of disk; anterior 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 behind, and with sculpture similar to anterior. Left valve slightly less ventricose than right, with narrow rounded ribs and wide concaye-bottomed interspaces; surface ornamented by fine, regular, raised, wavy, concentric lines, and sometimes more or less tesselated; ears obliquely truncated and sculptured with sharp incremental lines and sometimes by obsolete radiating ridges. Dimensions.—Alt. 105 mm.; long. 110 mm.; hinge line 48 mm.; diameter 15 mm. The measurements are for a specimen considerably under the average in size. This species has caused considerable confusion in the nomenclature of the West Coast. In 1855 Conrad described a couple of small right valves of P. caurinus und named the species **Pecten Heermanni.” The following is his original descrip- tion and notes (see synonymy above): ‘‘Suborbicular, thin, compressed; ribs about 21, square, smooth; ears moderate in size. Locality, California. Doctor Heermann. Allied to 7. choreus of the Virginia Miocene, but very distinct; only two interior valves were obtained; slightly convex.” The type of P. Zeermanni (so labeled in Conrad’s own writing), and the other specimen referred to in the description are now in the Philadelphia Academy of Sciences, where they were examined and photographed by the writer. They are both right valves of young P. caurinus and undoubtedly came from the unique bryozoan marl of Santa Barbara, both specimens showing the characteristic matrix and blue-gray color of specimens of P. caurinus from that locality. Some time after 1855 Conrad labeled a P. estrellanus and also some fragments of P. miguelens?s in the National Museum with the name **7?. //eermann?.” One of these latter specimens is referred to by Doctor Dall (see Dall, 1898 and 1901) as the type of P. Heermanni. This error of Conrad’s caused Dall to apply the name **Heermanni” to P. estrellanus. The type of 2. Meekii Conrad is in the National Museum (No. 13333) and has been examined by the writer. It, also, is a P. caurinus from the bryozoan marl of Santa Barbara. The ‘“‘San Raphael Hills,” from whence the type of P. Mechii came, according to Conrad, are near Santa Barbara. P. Yessoensis Jay, from Amori, Rikonoken, Japan, differs from P. caurinus by haying a more convex shell, wider, lower, more rounded ribs on the right valve, less prominent ribs on the left valve, and by haying larger ears, which are truncated more nearly at right angles. P. caurinus ranges from the Pliocene upward. It has been reported from the Miocene by several authors, but so far none of these records have been authenticated. PLIOCENE PECTENS. 1038 A Pecten having 19 ribs, and allied to, if not identical with, 7. caurinus, was found in the lower Pliocene (4) sandstone at the mouth of the Raft River, Jefferson County, Wash. The ribs on the right yalve of this specimen were narrower and those on the left valve were somewhat higher than those of a typical caurinus. Pecten caurinus 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 cases, higher and narrower than in the typical form. On Eel River above the mouth of Price Creek, Mr. J. S. Diller found P. caurinus associated with the following fauna: Asty/is richthofeni, Callista subdiaphana, Chrysodomus n. Sp., Kennerlia grandis, IEG hicarinata, Macoma calearea, Maconia (ef.) nasuta, Natica clausa, Panomya ampla, Pleurotoma perversa, Priene n. sp. (4) near oregonensis, Tapes staleyi, Thracia trapezoides, Trophon near mu/ticostatus, and Yoldia scissurata. This is a Pliocene fauna. From Switch Gulch to French Guleh, on the Eel River, P. cauminus is found with the following: Cardiwm meekianum, Natica clausa, Mactra (ef) californica, Siliqua patula, Macoma calcarea, M. inquinata, Tapes staleyi, Tresus nuttalli, Solen (cf.) sicarius, Pleurotoma perversa, Thracia trapezoides, Chrysodomus nv. sp., Yoldia scissurata, Psephis (ef.) tantilla, Trophon near multicostatus, Seutella ov ichinarachnius sp. indet. This is also a Pliocene fauna. A magnificent specimen of P. cavrénus, Measuring nearly 200 millimeters in altitude, was found by Dr. Stephen Bowers in the Phocene near Santa Paula, Ventura County. The type of P. caurinus is in the U.S. National Museum, No. 5954. RANGE. Living. Puget Sound (Carpenter). Pleistocene. Santa Barbara; San Pedro (Cooper, Mrs. A. E. Bush, Arnold). Pliocene. Mouth of Raft River, Jefferson County, Washington (Arnold); above mouth of Price Creek, from Switch Guleh to French Gulch, and south of the middle of Rio Dell Bluff, Eel River (J. S. Diller); Eel River, Humboldt County (W.5. Monroe, A. C. Lawson); T. 1 N., Humboldt meridian, Humboldt County (J. M. Graham); Eagle Prairie, Humboldt County; San Fernando, Los Angeles County (Cooper); Santa Paula, Ventura County (Bowers, Watts); Santa Barbara; San Pedro (Arnold). Prcren (PATINOPECTEN) HEALEYI n. sp. Pl. XXXVI, fies. 1 and la; Pl. XOX VII) figs. 1, la, and 2: 1879. Pecten expansus Dall, Proc. U. 8. Nat. Mus., vol. 1, 1879, p. 14; not Pecten expansus Smith, Quart. Jour. Geol. Soc., vol. 3, 1847, pp. 413, 419, pl. 18, fig. 21. 1898. Pecten ( Patinopecten) expansus Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 706, pl. 26, fig. 1. 1905. Pecten (Patinopecten) expansus Dall, Arnold, Mem. Cal. Acad. Sci., vol. 3, 1903, p. 108. 1904. Pecten expansus Dall, Rivers, Bull. So. Cal. Acad. Sci., vol. 3, no. 5, p. 69. Description.—Shell averaging about 130 millimeters in altitude, length about equal to height, inequivalve (the right slightly more ventricose than the left), equilateral, and with smooth margins; base evenly rounded; sides only slightly 104 TERTIARY AND QUATERNARY PECTENS OF 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. Dimensions. —Alt. 112 mm.; long. 112 mm.; hinge line 50 mm.; diameter 18 mm. The measurements are of a specimen somewhat below the average in size. A fine specimen 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 highly developed medial sulci, and intercalary ribs on the left valve that almost equal the primary ones in importance. 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 have 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. healeyi with 17 ribs is found at Brea Canyon, 4 miles southeast of Newhall, Los Angeles County, associated with the following fauna: Phacoides acutilineatus, P. richthofeni, Dosinia ponderosa (4), Tritonium sp., Conus n. sp. (4), Pomaulax sp., Turritella cooperi, Tellina idx, Neverita recluziana, Trochita jilosa, Chione near succincta, Cardium near corbis, Nassa near fossata. This fauna is probably well down in the Pliocene. P. healeyi 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 litera- ture of the Pacific coast as P. expansus was found to be preoccupied. Since, however, PLIOCENE PECTENS. 105 it becomes necessary to rename the species, it is with pleasure that the writer is enabled to dedicate it to Dr. William Healey Dall. RANGE. Pliocene. Purisima to Pescadero, and Punta Afio Nuevo, San Mateo County (J. P. Smith, Arnold); Temescal Canyon, Santa Monica Mountains, Los Angeles County (Rivers); Pacific Beach, San Diego County, (Hemphill, Dall, Arnold, and others); Tia Juana, Mexico (A. W. Greeley); Brea Canyon, 4 miles south- east of Newhall, Los Angeles County (U.S. Nat. Mus.) PECTEN (PATINOPECTEN) PURISIMAENSIS nh. sp. Pl) SOXGRTIV, fig) 2; PID XOX, figs: land Ia. 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 mod- erate angle. Right valve with about 24 prominent, T-rail-shaped ribs, flattened and sometimes faintly dichotomous above, overhanging deep, channeled, flat- bottomed interspaces, 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 about two-fifths length of disk; anterior ear only slightly longer than posterior, sculptured by about three prominent radiating ridges and numerous imbricating incremental lines; byssal notch promi- nent, but not deep, being equal in width to one-half width of ear; posterior ear obliquely truncated, and ornamented by about three prominent radiating ribs and imbricating incremental lines. Left valve with narrow, rather sharp, concave- sided 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. Dimensions.—Alt. 125 mm.; long. 125 mm.; hinge line 50 mm.; diameter 25 mm. This magnificent species is allied to P. coosensis and P. dilleri, one of which is probably its precursor. 7”. purisimaensis 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 /. coosensis by the prominent radial sculpture of the ears. P. purisimaensis is characteristic of the Purisima (lower Pliocene) formation, where it is associated with P. healey?, P. nutter’, Crepidula princeps, Phacoides acutilineatus, Rostellaria indurata, ete. : The type is from the beds on the coast north of Pescadero, and is now in the collection of Delos Arnold. RANGE. Pliocene (lower). Purisima to Pescadero, and Punta Ano Nuevo, San Mateo County (J. P. Smith; W. R. Hamilton; Arnold). 106 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. Precren (PATINOPECTEN) TURNERI n. sp. Pl. XXIV, fig. 4; Pl. XOXGKV, figs. 20and’ 3: 1888.? Pecten propatulus Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 258 (‘“Tomales, Marin ). County’ Description.—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 nearly st ‘aight and sloping at a rather low angle. Right valve with eighteen to twenty-two high, narrow, flat-topped, concave- sided ribs, which, in most cases, show a distinct medial sulcus after reaching a length of 30 or 35 millimeters; 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 fine incremental lines; byssal notch shallow but distinct; posterior ear with sculpture similar to anterior. Left valye with narrow rounded ribs, which are separated by round-bottomed and coneave-sided interspaces much wider than the ribs; surface sculptured by fine, distinct, wavy, concentric lines; ears as in right valve, except lacking byssal notch. Hinge as in 2. caurinus. Dimensions.— Alt. 65 mm.; long. 65 mm.; hinge line 35 mm.; diameter 6 mm. The type is a smaller specimen than the average of this species. P. turneri is allied to the group of which /P. caurinus 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. H. 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 cepartment of geology, Leland Stanford Junior University. RANGE. Pliocene. Tomales Bay, Marin County (Turner). Precren (NopIPECTEN) VEATCHII Gabb. Pl. XL, figs. 1 and la. 1869. Pecten Veatchii Gabb, Pal. Cal., vol. 2, 1869, p. 32, pl. 10, fig. 56. 1888. Liropecten veatchii Gabb, Cooper, Seventh Ann. Rept. Cal. St. Min., 1888, p. 246. 1898. Pecten Veatchii Gabb, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 705. Description.—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 PLIOCENE PECTENS. 107 ‘whole surface is covered by several more or less prominent concentric undu- lations and numerous fine, squarish, imbricated, 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; posterior ear much smaller than anterior, but sculptured in a similar manner. Left valve with about 7 broad, flat, round-cornered ridges of unequal size, which are separated by interspaces 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 become more or less prominent nodes toward the apex of the shell; ears similar to those of the right valve, except that the anterior one has a simple arcuate end and no notch. Dimensions.—A\t. 130 mm.; long. 145 mm.; hinge line 75 mm.; diameter o0 mim. This species is quite similar to and is no doubt the precursor of P. swbnodosus, from which it differs by attaining a larger size and haying fewer and broader ribs. Like the living form, it is quite variable 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, off the coast of Lower California, where it is associated with P. cerrosensis, P. lecontei, Ostrea veatchiz, and O. cerrosensis in beds of probable Pliocene age. Doctor Cooper confused one of the large Miocene Pectens (7. magnolia) with this species when he reported it from the Pliocene of Ojai Valley, Ventura County. (See Seventh Ann. Rept. Cal. St. Min., 1888, p. 246.) The specimen figured is the type, which is now in the collection of the University of California. RANGE. Pliocene. Cerros Island, off Lower California (Dr. J. A. Veatch). PrcreN (CHLAMYS) BARTSCHI n. sp. Pl. XLL, fig. 3. Description.—Adult shell averaging about 60 millimeters in altitude, somewhat shorter than high, convex, slightly inequilateral; base regularly rounded; margins smooth. Valves with about 40 prominent (more or less unequal) narrow thread- like ribs, ornamented on top by numerous short imbricating spines; interspaces deep, narrow, and channeled; lateral areas rather narrow, perpendicular to disk, and slightly concave. Ears similar to those of P. dslandicus. Dimensions.—Alt 62 mm.; lat. 50 mm.: diameter 28 mm. This species, of which only two or three rather poorly preserved specimens are known, is quite closely related to P. opuntia, but is readily distinguishable by its much larger size when adult, lack of concentric constriction in the later stages of growth, and relatively shorter disk. P. hartschi is found in beds of probable lower Pliocene age at Crescent City, Cal., where it is associated with Zerebratalia near hemphilli Dall, Phacoides 108 TERTIARY AND QUATERNARY PEOCTENS OF CALIFORNIA. acutilincatus Conrad, and Pecten parmeleei Dall. The type is figured and is now in the U.S. National Museum, No. 164841. RANGE. Pliocene (lower). Crescent City, Del Norte County, Cal., south side of Light-House Point, north of wharf (Diller). PECTEN (CHLAMYS) BELLILAMELLATUS Nl. sp. Pl. XUI, figs. 6, 6a, 7, and 7a. Description.—Shell averaging about 18 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 much wider than ribs. with narrow, flat bottoms; surface sculptured by numerous, regular, equidistant, thin, concentric, imbricating lamelle, 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 equal to the length of the disk; ears equal in length; anterior ear convexly truncated, separated from the disk by a deep, sharply defined, byssal notch, and sculptured by fine, regular, incremental lamelle and five or six subequal radials; posterior ear acutely pointed, radially striate, and with incremental sculpture similar to but not quite as prominent as that of the anterior. Left valve similar to right; anterior ear more prominently sculptured, both radially and concentrically, than the posterior. Dimensions.—Alt. 18 mm.; long. 18 mm.; hinge Jine 18 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 beautifully curved incremental lamellae. It is easily distinguishable from /”. /atiauritus and varieties, with which it is allied, by the above-enumerated characteristics. P. bellilamellatus is so far known only from the Pliocene at Pacific Beach, San Diego, where it is associated with P. healey/, P. stearnsi/, etc. Type in the collection of Delos Arnold. RANGE, Pliocene. Pacitic Beach, San Diego County (Arnold). PrecrEN (CHLAMYS) HASTATUS Sowerby. Pl) XLI, fig. 4; Pl: XULIM, figs. 1, 1a, 2, and 2a. 1843. Pecten hastatus Sowerby, Thes. Conch., vol. 1, 1848, p. 72, pl. 20, fig. 236 (not of Reeve, 1852= P. yar. hericius Gld.; in part not of Carpenter, 1863; nor of Cooper, 1888). 1857. Pecten altiplectus [typ. err.] Conrad, Proc. Acad. Nat. Sci. Phila., for 1856, Ist ser., vol. 8, 1857, p. 313. 1857. Pecten altiplicatus Conrad, Pac. R. R. Rept., vol. 7, 1857, p. 191, pl. 3, fig. 2. 1869. Pecten hastatus Sowerby, Gabb, Pal. Cal., vol. 2, 1869, p. 104. PLIOCENE PECTENS. 109 1887. ?Pecten hastatus Sowerby, Whiteayes, Trans. Roy. Soc. Canada, vol. 4, sec. 4, 1887, p. 119. 1898. Pecten hastatus Sowerby, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 708. 1903. Pecten (Chlamys) hastatus Sowerby, Arnold, Mem. Cal. Acad. Sei., yol. 3, 1908, p. 109, pl. 11, figs. 4, da. 1904. Pecten hastatus Sowerby, Keep, West. Am. Shells, p. 40. Description.—Shell averaging about 64 millimeters in altitude, slightly shorter than high, inequivalye, equilateral (except for ears), compressed and with serrate margins; base evenly rounded below; sides slightly concave aboye. 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 by 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 equal 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 8 prominently spiny radials and minor riblets, and imbricating incremental lines; byssal notch deep and almost as wide as ear; posterior ear small, and sculptured by fine, spiny radials and imbricating incremental lines. Left valve with about 9 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 fine 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 obsolete cardinal crura. Color, golden yellow to pink, the left valve being the darker. Dimensions. —Alt. 64 mm.; long. 62 mm.; hinge line 31 mm.; diameter 22 mm. This beautiful species, which is the southern representative of the group of which var. hericius is the normal form, is characterized by the great prominence of the spines which adorn the major ribs of both valves. Se (U.S. Fish Commission). . PECTEN (ZEQUIPECTEN) PALMERI Dall. Pl. L, figs. 2, 2a, 3, and 3a. 1897. Pecten palmeri Dall, Nautilus, vol. 11, No. 8, Dee., 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 PECTENS. 13¢/ adult, separated by narrower channeled interspaces, vach with a mesial thread; all crossed by lamellose, concentric, rather sparsely distributed elevated lines; submar- gins and ears closely radially threaded with imbricated threads. Both valves similarly sculptured.” Dimensions.—Alt. 47.5 mm.; long. 53 mm.; diameter about 20 mm. This species is easily distinguishable by its flat, orbieular disk and peculiar 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 years ago. RANGE. Living. Near head of Gulf of California (E. Palmer). PrcreN (PLAGIOCTENIUM) PAUCICOSTATUS Carpenter. Pl. XX XIX, figs. 3, 3a, and 4. 1863. Pecten paucicostatus Carpenter, Brit. Assn. Rept., 1863, p. 645. 1865. Pecten paucicostatus Carpenter, Ann. and Mag. Nat. Hist., 3d-ser., yol. 15, 1865, p. 179. 1888. Pecten paucicostatus Carpenter, Kiister and Kobelt, Conch.-Cab., vol. 17, pt. 2, Spondylus und Pecten, no. 9, p. 281. Description.—Shell averaging about 35 millimeters in altitude, longer than high, subequivalve, moderately ventricose; thick-shelled; margins smooth. Right valve subequilateral, slightly more ventricose than the left; ribs 12 to 14, prominent, convex-topped, subangular; interspaces slightly wider than the ribs, somewhat rounded; incremental sculpture fine and regular, not looped; hinge line about five- sevenths 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-bottomed; ears similarly sculptured to those of right valve. Dimensions. —Alt. 34.5 mm.; long. 37 mm.; hinge line 25 mm.; diameter 13 mm. The specimen described is No. 15643, U. 5. N. M. It is dark brown in color, with no patterns or blotches. This species is distinguishable from P. latiauritus and varieties by its much heavier shell, dark uniform color, shorter hinge line, and fne uniform concentric lines. The type is labeled ‘Santa Barbara” by Jewett, but is unquestionably from the Gulf of California, as no species with its characteristics are known outside of the tropical fauna. Besides, Jewett was known to be quite careless regarding the localities of his specimens. RANGE. Living. Gulf of California (Jewett, Stearns). 1388 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. Proren (PsecDAMUSIUM) DAvIDsSONI Dall. Pl. L, figs 4 and 4a. 1897. Pecten Davidsoni Dall, Nautilus, vol. 11, No. 8, Dec., 1897, p. 86. 1902. Pecten Davidsoni Dall, Proc. U. 8. Nat. Mus., vol. 24, 1902, p. 559, pl. 40, figs. 5, 6. 1904. Pecten davidsoni Dall, Keep, West Am. Shells, p. 41, figs. 21a, 216. The original description is as follows: Description.—* Shell small, suborbicular, compressed, waxen white, the left valve with 21 rounded ribs, sarmounted by (when not worn off) 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 riblets: posterior ear transversely striated, very small, anterior one with four or five scaly 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.” Dimensions.—Alt. 14 mm.; long. 14 mm.; diameter 3.5 mm. This little shell somewhat resembles P. alashensis externally, but lacks the radiating lire internally, is smaller, and bas faint radiating sculpture on the right valve, which is wanting in 72. a/askensis. 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. RANGE. Living. Davidson Bank, Alaska, 280 fathoms; north of Unalaska, in Bering Sea, 351 fathoms (U. S. Fish Commission). Prctren (PseuDAMUSIUM) RANDOLPH! Dall. Pl. XLVIII, figs. 2 and 2a. 1897. Pecten Randolphi Dall, Nautilus, vol. 11, No. 8, Dee., 1897, p. 86. 1902. Pecten Randolphi Dall, Proc. U. S. Nat. Mus., vol. 24, 1902, p. 559, pl. 40, fig. 2. 1904. Pecten randolphi Dall, Keep, West Am. Shells, p. 41. The original description is as follows: Description.—** Shell small, thin, glassy, unsculptured, except by minute ‘ Camp- tonectes? 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 any fold or sinus, outline suborbicular, valves compressed, espe- cially 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; cteno- lium with four or five functional spines.” Dimensions.—Alt. 27.5 mm.; long. 26 mm.; diameter 5 mm. This species is the living representative of the group consisting of the three very closely allied, if not identical forms, 2. peckhami, P. pedroanus, and P. randolphi. 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 related. 7”. peckhami averages smaller than the other two and has usually only four radials on the right anterior ear, while P. pedroanus is the largest of the group and is generally much more prominently undulated than the others. The three species are so much alike, at any rate, that with the usually poor state of preservation of the Miocene fossil forms it would be impossible to make any definite distinctions in 99 per cent of the cases that have fallen under the observation of the writer. This being true, it is quite evident that the two forms, P. pedroanus and P. peckham/, which heretofore have always been considered diagnostic species of the Miocene, at once lose their value as agents of correlation. A further study of well-preserved fossil material, if any is ever obtained, will undoubt- edly tend to make clear the relations existing between the members of this very interesting little group. The type of P. randolphi (U.S. N. M., 107749) was dredged by the U. S. Fish Commission steamer Albatross off Destruction Island, Washington, in 516 fathoms, bottom temperature, 38° F. RANGE, Living. Bering Sea to West Mexico, in 225 to 1,005 fathoms (U. S. Fish Commission. ) Prcren (PSEUDAMUSIUM) RANDOLPHI Dall var. TILLAMOOKENSIS n. var. Pl. XLVIII, figs. 3 and 3a. Description.—Shell resembling 7. randolphi in outline and general charac- teristics. Disk ornamented by numerous more or less prominent, fine, radiating ridges, microscopic radiating strive, 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 strive cover the whole surface of the disk and ribs and in a general way radiate from the umbo, but are seldom parallel to the ribs; on the portion of the disk and ear posterior to the umbo the striz are perpendicular to the lines of growth and are thus nearly parallel and not radiating. The right anterior ear has from 6 to 12 prominently imbricated radials. Dimensions. —Alt. 30 mm.; long. 30 mm.; hinge line 17 mm.; diameter 7 mm. This variety appears to combine some of the characters of P. vancouwverensis with P. randolphi, having the prominent radial sculpture of the former and the relatively large, undulated disk of the latter; the ears in P. var. ¢//lamookensis are sculptured more nearly like the former, having from 1 to 6 more radials than P. randolphi. 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 type, U. 5. N. M. 150233, is from off Tillamook Bay, Oregon, at U.S. F. C. Sta. 3346, at a depth of 786 fathoms. RANGE. Living. From north of Unalaska, 351 fathoms, to off Tillamook Bay, 736 fathoms. (U.S. Fish Commission.) 140 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. PrECTEN (PSEUDAMUSIUM) VANCOUVERENSIS Whiteaves. Pl. LII, figs. 3 and 3a. 1886. Pecten caurinus Dall (not Gould), Bull. Mus. Comp. Zool., yol. 12, 1886, p. 216, pl. 5, fig. 4 (supposed young of P. cawrinus). 1887. Pecten (Pseudamusium) Alaskensis Whiteaves (not Dall), Trans. Roy. Soc. Canada, vol. 4, see. 4, for 1886, 1887, p. 119. 1889. Pecten caurinus Dall (not Gould), Bull. U.S. Nat. Mus., No. 37, 1889, pl. 5, fig. 4 (supposed young of P. caurinus). 1893. Pecten (Pseudamusiwm) Vancouverensis Whiteayes, Ottawa Naturalist, vol. 7 (being vol. 9, Trans. Ottawa Field-Nat. Club), 1893, p. 133, pl. 1, figs. 1, 1a. 1893. Pecten ( Pseudamusium) Vancowerensis Whiteaves, Newcombe, Bull. Nat. Hist. Soc. Brit. Co- lumbia, 1893, art. 5, p. 53. 1895. Pecten (Pseudamusium) Vancourerensis Whiteaves, Taylor, Trans. Roy. Soc. Canada, 2d ser., vol. 1, 1895, sec. 4, p. 26. 1904. Pecten vancouverensis Whiteaves, Keep, West Am. Shells, p. 41. The original description is as follows: Description.—* Shell small faveraging about 7.5 millimeters in altitude], equi valved, compressed lenticularly, both valves being equally convex, ovately subcircu- lar in outline apart from the ears and rather oblique; valves extremely thin and fragile, translucent and almost transparent, pale horn color with a slightly yellowish hue. Beaks placed a little behind the midlength; hinge line straight and very long; ears unequal in size, the posterior pair, which are much smaller than the anterior, alike, indistinctly detined, and merging gradually and imperceptibly into the general convexity and marginal contour of that side of each valve; anterior ears large, sub- triangular, prolonged laterally, and longer than high, distinctly defined, that of the left valve somewhat convex in outline above and concave below, that of the right valve with a deep and acutely angular byssal sinus at its base. 7 “Surface marked by densely crowded and exceedingly minute, irregular, and rarely continuous, but, on the whole, radiating, simple or bifureating raised lines, also by comparatively large, regularly disposed, and distant squamose 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 be clearly 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.” Dimensions.— Alt. 7.5 mm.; long. 7.75 mm.; diameter 2.25 mm. This beautiful little /%cfen is easily distinguishable from the other members of the same group by its smaller size when adult, fine radiating lines of sculpture externally, and by its relatively longer hinge line. RANGE. Living. Sitka Harbor, 12 fathoms (Dall); Forward Inlet, Quatsino Sound (Daw- son); Departure Bay (Taylor, Macoun); off San Pedro, Los Angeles County, 200 fathoms (Oldroyd); Avalon Harbor, Catalina Island, 15 fathoms (Arnold). DESCRIPTIONS OF SUBGENERA AND SPECIES. 141 UNIDENTIFIABLE PECTENS. PrcCTEN CATILLIFORMIS Conrad. 1856. Pecten catilliformis Conrad, Pac. R. R. Rept., vol. 5, p. 329, pl. 9, fig. 83. 1888. Pecten catilliformis Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., for 1887, p. 257 (in part). 1898. Pecten catilliformis Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, p. 700. Original description and notes. —*Orbicular, plano-convex, with radiating strive and distinct rounded ribs; ears equal. “This large Pecten has such a general resemblance to P. madisonius 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 liying 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 type of this species was the internal cast of some large Lyropecten (+) probably allied to crassicardo, estrellanus, or bowersi. According to Dall the type is unknown as the species was described by Conrad from drawings made by Prof. W. P. Blake. The figure in the Pacific Railroad Report is so poor and the description so meager that it is probable the species will remain for a long time unrecognized. PrCTEN NEVADANUS Conrad. 1856. Pecten nevadanus Conrad, Pac. R. R. Rept., vol. 5, p. 329, pl. 8, fig. 77. 1888. Pecten nevadanus Conrad, Cooper, Seventh Ann. Rept. Cal. St. Min., for 1887, p. 258 (in part). 1898. Pecten nevadanus Conrad, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 700. Oviginal description and notes.—** Ovate, flat or slightly concave; ribs 17, large, flattened on the back; interstices strongly wrinkled transversely. ‘This shell is so nearly allied to V. (should be P.) Hhunphreysii of Maryland that, taken in connection with P. catilliformis, * * * it may be regarded asa Miocene species. The strata in which they occur may safely be referred to that period. ** Locality.—Ocoya Creek [Kern County].” This species, like the last, was, according to Dall, described by Conrad from one of Professor Blake’s drawings of an external mold. The figure and description in the Pacific Railroad Report appears to fit 7. bowers’ quite closely. The size of the shell, number and shape of ribs, and the characteristically sculptured byssal area are similar in the two species, but the writer has hesitated to place the latter in the synonymy of P. nevadanus, owing to the uncertainty of using so few characteristics in a definite specific determination of such importance. PrCTEN PYXIDATUS Carpenter. 1863. Pecten pyxidatus Carpenter, Brit. Assn. Rept., 1863, p. 667. 1898. Pecten pyxidatus Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 711. This species is listed by Carpenter as having been collected by Captain Stone at Guaymas, Gulf of California. According to Doctor Dall this is probably a Chinese species. 142 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. PECTEN SUBCRENATUS Carpenter. 1863. Pecten subcrenatus Carpenter, Brit. Assn. Rept., 1863, p. 667. 1898. Pecten subcrenatus Carpenter, Dall, Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, 1898, p. 711. This species is cited by Carpenter as being a possible synonym for the P. pyxidatus above referred to. It is characterized as a list name by Doctor Dall, and is now unidentifiable. PECTEN TOWNSENDI Gould. 1863. Pecten Townsendi Gould, Carpenter, Brit. Assn. Rept., 1863, p. 432. 1898. Pecten Townsendi Gould, Dall, Traus. 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, consequently, now unidentifiable. BIBLIOGRAPHY. Acassiz, Louts. 1856. Notice of the fossil fishes: Pac. R. R. Rept., vol. 5, appendix, pp. 313- 316, pl. 1. Washington. Anton, H. E. 1839. Verzeichniss der Conchylien. Pectinea, pp. 18-20. Halle. ArnoLp, Dros and Rapn. 1902. The marine Pliocene and Pleistocene stratigraphy of the coast of southern California: Jour. Geol., vol. 10, No. 2, pp. 117-138, pls. 1-5, figs. 1-7. Chicago. ARNOLD, RALPH. 1903. The paleontology and stratigraphy of the marine Pliocene and Pleistocene of San Pedro, Cal.: Mem. Cal. Acad. Sci., vol. 3, pp. 420, pls. 37. San Francisco, June, 1903. Arnoup, Ratpu, Harn, H. L., and. 1904. The diabase of the Santa Cruz Mountains in San Mateo County, Cal.: Proc. Am. Phil. Soc., vol. 43, pp. 15-53, figs. 1-25. Philadelphia. AsHLEY, G. H. 1895. The Neocene stratigraphy of the Santa Cruz Mountains, California: Proc. Cal. Acad. Sci., 2d ser., vol. 5, pp. 273-367, pls. 22-25. San Francisco. Brake, Wm. P. 1856. Notice of remarkable strata containing the remains of Infusoria and Polythalamia in the Tertiary formation of Monterey, Cal.: Proce. Acad. Nat. Sci. Phila., vol. 7, 1855, pp. 328-331. Brauns, Davin. 1881. Geology of the environs of Tokio: Mem. Sei. Dept., Univ. of Tokio, No. 4. / Broeeer, W. C. 1901. Om de senglaciale. og postglaciale nivaforandringer i Kristianiafeltet (Molluskfaunan): 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 Mollusca of the west coast of North America: Rept. Brit. Asso. Ady. Sci. for 1856. pp. 159-3868, + pls. London. 1864. Supplementary report on the present state of our knowledge with regard to the mollusks of the west coast of North America: Rept. Brit. Asso. Ady. Sci. for 1863, pp. 517-686. London, 1864. CiarK, W. B. 1891. Correlation papers, Eocene: Bull. U. 5S. Geol. Survey, No. 83. Washington. Conran, T. A. 1856. Descriptions of the fossil shells: Pac. R. R. Rept., vol. 5, appendix, pp: 317-330, pls. 2-9. Washington. 1857. Description of three new genera; twenty-three new species middle Ter- tiary fossils from California, and one from Texas: Proc. Acad. Nat. Sci. Phila., ist ser., vol. 8, 1856, pp. 312-316. Philadelphia. 1857. Description of the Tertiary fossils collected on the survey: Pac. R. R. Rept., vol. 6, pt. 2, pp. 69-73, pls. 2-5. ‘Washington. 1857. Report on the paleontology of the survey: Pac. R. R. Rept., vol. 7, pt. 2, pp. 189-196, pls. 1-10. Washington. 1863. Descriptions of new genera, subgenera and species of Tertiary and Recent shells: Proce. Acad. Nat. Sci. Phila., 2d ser., vol. 6, 1862. pp. 284-291. 1867. Paleontological miscellanies: Am. Jour. Conch., vol. 3, 1867, pp. 5-7. Philadelphia. Coorrr, J. G. 1888. Catalogue 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. ID Aro View Ele 1871. Diagnoses of sixty new forms of mollusks from the west coast of America and the north Pacific Ocean: Am. Jour. Conch., vol. 7, pp. 93-160, pls. 13-16. Philadelphia. 1878. Fossil mollusks from later Tertiaries of California: Proce. U. S. Nat. Mus., vol. 1, pp. 10-16. Washington. 1886. Report on the results of dredging by the U. 8. Coast Survey steamer “Blake.” XXIX. Report on the Mollusca, pt. 1, Brachiopoda and Pelecypoda: Bull. Mus. Comp. Zodél., vol. 12, No. 6, pp. 171-818, pls. 1-9. Cambridge, Mass., September, 1886. 1889, 1903. A preliminary catalogue of the shell-bearing ma-_ine mollusks and brachiopods of the southeastern coast of the United States, with illus- trations of many of the species: Bull. U. S. Nat. Mus., No. 37, pp. 215, pls. 47. Washington, 1889. Reprint, pp. 232, pls. 95. Washington, 1903. 144 TERTIARY AND QUATERNARY PECTENS OF CALIFORNIA. Dati, W. H.—Continued. 1897. New west American shells: Nautilus, vol. 11, No. 8, pp. 85-86. Phila- delphia. ; 1898. The Tertiary fauna of Florida; Family Pectinide: Trans. Wagner Free Inst. Scei., vol. 3, pt. 4, pp. 689-758, and plates. Philadelphia, April, 1898. 1898. A table of North American Tertiary horizons, correlated with one another and with those of western Europe, with annotations: Kighteenth Ann. Rept. U. S. Geol. Survey, pt. 2, pp. 323-348. Washington. 1901. A new Lyropecten: Nautilus, vol. 14, No. 10, pp. 117-118. Philadelphia. 1902. Illustrations and descriptions of new, unfigured, or imperfectly known shells, chiefly American, in the U. S. National Museum: Proc. U.S. Nat. Mus., vol. 24, pp. 499-566, pls. 27-40. Washington. 1904. Neozoic invertebrate fossils; a report on collections made by the expe- dition: Harriman Exped. Repts., Alaska Geol., pp. 99-122, pls. 9-10. Dati, W. H., and Harris, G. D. 1892. Correlation papers, Neocene: Bull. U. 5. Geol. Survey, No. 84. Wash- ington. DILLER, J. 8. 1896. A geological reconnaissance in northwestern Oregon: Seventeenth Ann. Rept. U.S. Geol. Survey, pt. 1, pp. 441-520. Washington. Farrpanks, H. W. 1904. San Luis folio: Geologic Atlas U. S., folio 101, U. S. Geol. Survey. Washington, June 10, 1904. Gass, W. M. 1864, 1869. Geological Survey of California, Paleontology, vol. 1, pp. 243, pls. 32, 1864; vol. 2, pp. 299, pls. 36, 1869. Philadelphia. Harun, H. L., and Arno“tp, Raven. 1904. (See Arnold, Ralph, 1904.) Haury, Homer. 1904. Water resources of the Salinas Valley, California: Water-Sup. and Irr. Paper No. 89, U. 8S. Geol. Survey. Washington. UR RIGS) GewlD se) Annie Ele rane 1892. (See Dall, 1892.) JACKSON, R. TT. 1890. Phylogeny of the Pelecypoda: Mem. Bost. Soc. Nat. Hist., vol. 4, No. 8. Boston. Keep, JOsian. 1892. West Coast Shells, pp. 230, figs. 182. San Francisco. 1904. West American Shells: a description in familiar terms of the principal marine, fresh-water, and land mollusks of the United States found west of the Rocky Mountains, including those of British Columbia and Alaska, pp. 360, text figs. 303. The Whitaker & Ray Co., San Francisco. Kopett, W., Ktsrer, C. H., and. 1888. (See Kiister, C. H., 1888.) BIBLIOGRAPHY. 145 Kuster, C. H., and Koprettr, W. 1888. Systematisches Conchylien-Cabinet (Martini und Chemnitz) Die Gattungen Spondylus und Pc ten, pp. 296, pls. 72. Bauer & Raspe, Nurnberg, 1888. Lawson, A. C. 1893. The Post-Pliocene diastrophism of the coast of southern California: Bull. Dept. Geol., Univ. Cal., vol. 1, No. 4, pp. 115-160, pls. 8-9. Berkeley. 1894. The geomorphogeny of the coast of northern California: Bull. Dept. Geol., Univ. Cal., vol. 1, No. 8, pp. 241-272. Berkeley. 1895. Sketch of the geology of the San Francisco peninsula: Fifteenth Ann. Rept. U. S. Geol. Survey, 1893-94, pp. 399-476, pls. 5-12. Wash- ington. 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. 767-175. 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. 215-224. Sacramento. 1904. A note on the fauna of the lower Miocene in California: Bull. Dept. Geol., Univ. Cal., vol. 3, No. 16, pp. 377-881. Berkeley. Newcompg, C. F. 1893. Report on the marine shells of British Columbia: Bull. Nat. Hist. Soe. British Columbia, art. 5, pp. 29-72. Richard Wolfenden, Victoria. Osmont, VaNcE C. 1905. A geological section of the coast ranges north of the bay of San Francisco: Bull. Dept. Geol., Uniy. Cal., vol. 4, No. 3, pp. 39-87, pls. 6-7. 1905. Areas of the California Neocene: Bull. Dept. Geol., Uniy. Cal., vol. 4, No. 4, pp. 89-100, pls. 8-11. Parirerr, R. A. 1845. Abbildungen und Beschreibungen neuer oder wenig gekannter Conchy- lien, Bd. 1, Pecten, pp. 201-204, taf. viii, 6. Cassel. Repye, L. A. 1855. Conchologia Iconica, vol. 8, Monograph of the genus Pecten, species 1-176, pls. 1-85. London. Rivers, J. J. 1904. Descriptions of some undescribed fossil shells of Pleistocene and Plio- cene formations of the Santa Monica range: Bull. So. Cal. Acad. Sci., vol. 3, No. 5, May, 1904, pp. 69-72, fgs. 1-4. Los Angeles. 17260—No. 47—06——10 146 TERTIARY AND QUATERNARY PECTENS OF CALIFORNTA. Sowrrsy, G. B. 1835. Descriptions of new species of shells in the collection of Mr. Cuming: Proce. Zool. Soc. Lond., 1835, pp. 109-112. London. 1848. Thesaurus Conchyliorum, vol. 1, Monograph of the genus Pecten, pp. 45-82, pls. 12-20. London. SowERBY, 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. Rept. U.S. Geol. Survey, pt. 1, pp. 1005— 1060, pls. 63-67. Washington. TayLor, GrorGE W. 1895. Preliminary .catalogue of the marine Mollusca of the Pacific Coast of Canada, with notes on their distribution: Trans. Roy. Soe. Canada, 9d ser., vol. 1, sec. 4, pp. 17-100. Ottawa. Trask, J. B. 1855. Descriptions of Californian 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: Jour. Geol., vol. 6, pp. 483-£99. Chicago. VaucHan, IT. W. 1900. The Eocene and Oligocene coral faunas of the United States: Mon. U. S. Geol. Survey, vol. 39, pp. 263, pls. 24. Washington. VERRILL, A. E. 1897. A study of the family Pectinide, with a revision of the genera and subgenera: Trans. Conn. Acad. Sci., vol. 10, pp. 41-96, pls. 16-21. WAVER, CHARLES E. 1905. Contribution to the paleontology of the Martinez group: Bull. Dept. Geol., Univ. Cal., vol. 4, No. 5, pp. 101-123, pls. 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 inyertebrata dredged, etc., in British Columbian waters: Trans. Roy. Soc. Canada, vol. 4, sec. 4, pp. 111-137. Montreal. 1893. Notes on some marine Invertebrata from the coast of British Columbia: Ottawa Nat., vol. 7 (being vol. 9 Trans. Ottawa Field Nat. Club), pp. 133-187, pl. 1. Ottawa. Wuitnry, J. D. 1869. Geological Survey of California, Paleontology, vol. 2, preface, pp. vii-xiy. Philadelphia. Winiramson, Mrs. M. B. 1902. A monograph on Pecten xquisulcatus Carpenter: Bull. So. Cal. Acad. Sci., vol. 1, No. 5, May 1, 1902, pp. 51-64, pls. 4-6. Los Angeles. Epi UEP Oey Ge 1M vae Al a WAL EOCENE PECTENS. (Unless otherwise stated all figures are approximately natural size.] Hrgs lePectens (Chiamiys) calkunst mesps) WG. Coby eps saree ea ere Exterior of imperfect right valve; altitude 29 mm. Tejon formation (Eocene), Sisar Valley, Ventura County, Cal. (8.)¢ Ines By Jaze (MOP) (Clas eto Wah BIN ae eceaeceanancbsbosnseaccndacsonedess Exterior of imperfect left valve; altitude 45 mm. Same locality as fig. 1. (S.) Bie. 3) -Pecten (iChlamys)landesi m. sp: US) NS Mi649265) Wyner seesas ea = == eeae ee Exterior of right valve; altitude 31 mm. LHocene, Little Falls, Lewis County, Wash. (ERR) Fia. 4. Pecten (Chlamys) landesi n. sp. U.S. N. M. 164926. Cotype Exterior of left valve; altitude 22.5 mm. Same locality as fig. 3. (M. P.) Hiawips -Pecten (Ohiamys) landesy n. sp) (U.S. Ne Mie 6492b5) (Gotypemes-- 252-2 - 46-22 = ana Exterior of right valve (coarse-ribbed form); altitude 34 mm. Same locality as last. (NESSES) Ere: 6: Pecien((Chlamys)) proavus'n. sp. U.S. N= M: 164930! Types 2.22222 =~ 5-22 5--- === 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.) IC Ue SENANe Ryo eheRSN HE ites (S243 oboe sea sae os anos eon aoe ree ssads Seca g es cossse>c seas Portion of disk showing sculpture; enlarged twice. Ere. 8. Pecten (Chlamys) proavus n. sp. U.S. N. M. 164930. Cotype..-.-..-.--...--...---- Fragment of a large specimen. Same locality as fig. 6. Fia. 9. Pecten (Propeamusium) interradiatus Gabb. Type.-.--------------------------------- Exterior of left valve; altitude 25 mm. Copied, with slight alteration, from Pal. Cal., vol. 2, pl. 38, fig. 98. Tejon formation (Eocene), New Idria, San Benito County, Cal. Ie, WO’ Snowe jyrg ee) te, Ce sa scsctassocosecoeusecses op onecd csocoscoeedrseneceaseoc Fia Mold of interior of left valve; altitude 25 mm. Copied, with slight alteration, from Palen C@alemvolee2.sply doy le 98. Sli ecteria WERO METI UUSIRUTTE) Mar Ute MCL CLOGS rel KD eee a eae Outline of hinge line and ear of right valve. Copied, with slight alteration, from Ral. Gal:, vol: 2; pl. 33, fig. 98a. Page. 52 aThe 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 conclu- sion of the explanation indicates the artist who retouched the figure. 148 PROFESSIONAL PAPER NO. 47 PL. II U. S. GEOLOGICAL SURVEY EOCENE PECTENS. JP Oy saCb a ALI OLIGOCENE-MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.) Fic. 1. Pecten (Propeamusium) clallamensis n. sp. U.S. N. M. 164923. Cotype----.------------ Imperfect mold of exterior of right valve; hinge line 6.5 mm., * 3. Olig« ycene-Miocene, Loe. 4070, Bean Point, King County, Wash. (M. P.) Fic. 2. Pecten (Propeamusium) clallamensis n. sp. U.S. N. M. 164922. Cotype .-------------- Imperfect mold of interior of left valve; altitude 7 mm., < 3. Oligocene-Miocene, Loc. 4100, 13 miles east of Pillar Point, Clallam County, Wash. (M. B.) Fia. 3. Pecten (Propeamusium) clallamensisn. sp. U.S. N. M. 164922. Type -.--------------- Mold of exterior of left valve; altitude 10 mm., <3. Same locality as fig. 2. (M. P.) ESTIG Hr ey SEVMN OSS OCC LIANE TN AS LL Wee pte ee a ee Portion of disk (not mold) enlarged 6 times. Fig. 4. Pecten ( Propeamusium) waylandi n. sp. U.S. N. M. 164924. Type .----.------------- Imperfect mold of exterior of left valye; longitude 7 mm., <3. Same locality (4100) as fig. 2. (M. B.) Fie. 5. Pecten (Propeamusium) waylandi n. sp. U.S. N. M. 164924. Cotype-.----------------- Mold of interior of right valve; altitude 10 mm., 3. Oligocene-Miocene, Loc. 4115, 2} miles west of Gettysburg, Clallam County, Wash. (M. B.) Fie. 6. Pecten (Pseudamusium) peckhami Gabb. Type .-------------------------------------- Exterior of left valve; altitude 21 mm. Copied from Pal. Cal., vol. 2, pl. 16, fig. 19. Speci- men from Ojai ranch, Ventura County, Cal. Fic. 7. Pecten (Pseudamusium) peckhami Gabb. Cotype ...-------------- .------------------ Outline of hinge line and ears of right valve. Copied from Pal. Cal., vol. 2, pl. 16, fig. 194. Same locality as fig. 6. Fria. 8. Pecten (Pseudamusium) peckhami Gabb. U.S. N. ME JIG4839)} 2.25 a nee eee erent See Casts of right and left valves in matrix. Monterey shale (Miocene), southeast of Pinole, Contra Costa County, Cal. (M. P.) Bra. 95 wPecten (Chlamys)\ brannent ne sp. li: S.J. UW. “‘Plastoty pers - ===. =< = eee Cast from imperfect moid (type) of left valve; hinge line 33 mm. Vaquero formation (lower Miocene), Tuff Hill, near Stanford University, Santa Clara County, Cal. (M. P.) Be, WOE Lezeiare (Clik) lentehOTH oe TOs Me Ib da WI! ao ectecaa st oonascodosssosc coneswescesnss Cast from fragment of mold of disk, showing sculpture. Same locality as fig. 9. (M. P.) Iie, Ik, Jeger (Cleo) (arcienaro 6 Rie WSs db Wis -osscctoocceccocHbonecocsesssbcassses> Cast from fragment of mold of disk, showing sculpture. Same locality as fig. 9. (M. P.) Fic. 12. Pecten (Pecten) sanctecruzensisn. sp. L. J. F. H. Cotype---------------------=----- Exterior of portion of right valve; longitude 48 mm. San Lorenzo formation (Oligocene), Bear Creek, Santa Cruz County, Cal. (M. B.) Fie. 13. Pecten (Pecten) sanctecruzensisn. sp. L.S.J.U. Plastotype ------------.------------ Exterior of cast from mold (type) of left valve; altitude 52mm. San Lorenzo formation (Oligocene), Twobar Creek, Santa Cruz County, Cal. (M. B.) 150 56 or on) 55 PROFESSIONAL PAPER NO. 47 PL. Ill U. S. GEOLOGICAL SURVEY sebb Shree OLIGOCENE-MIOCENE PECTENS. Fia. Fia. Fra. Fic. Fig. Fia. ren RIG: Fie. a Aa Helier MIOCENE AND PLIOCENE PECTENS. (Uuless otherwise stated all figures are approximately natural size. ] leeeecten) ecten) NeaniZOCns1s tle S em seem LLY, Ci sei et eer Exterior of right valve; altitude 86 mm. Carrizo formation (Miocene), Alverson Can- yon, San Diego County, Cal. (M. B.) liacgSame:specimen\iasifigy Di... 25.26 mast terse e eas se axe Sait ceise eeisines Seem ae esteioe eine Exterior of left valve. lbs Samespecimenvashigs lls === says ewe rstone ames evar se ales laine feria cian rae erie Profile of both valves viewed from rear. (M. P.) DEEP RECLEN CLE CLE NCCURTZOEN STS LXcH SD sin Olas ote Nene Les 4: (fees ee ee Exterior of left valve; altitude 63 mm. Miocene, Santa Rosalia, Lower California. (M. P.) SePELECLETUN WIREGLETE) RC CLTETUCOCTLS ES 0 S10 Sim Ll oS og NY L523 Exterior of imperfect right valve; longitude 44 mm. Same locality as fig. 2. (M. B.) BCw SAN CIS PCCUMOD IAS El toss pak t- iors ack Sere ST Eo SS erie ee eT oe Se ee eee eae Profile of right valve viewed from front. (M. P.) Aye ectens PRecten RCOLNOMens1S) tS} s ae Lio: dm Ulen sly Ge ee eee en re Exterior of slightly distorted right valve; altitude 47 mm. Lower Pliocene, Coalinga, Fresno County, Cal. (M. B.) do-goame-.specimenhas| Gs 4 = o2. aces jects ant eee Saee ose ce Seek ade oreR See eee ee Profile of right valve viewed from rear. (M. P.) DmeGLenn (BREGLEM) COAMING MENS iS d- Sp 1 @xest-iS-k OLY, 1C) a nee ere ree Exterior of left valve; altitude 35 mm. Lower Pliocene, Kreyenhagen’s ranch, Fresno County, Cal. (S.) 152 on 97 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. IV MIOCENE AND PLIOCENE PECTENS. rm hi PAG ACE Aes MIOCENE PECTENS. {Unless otherwise stated all figures are approximately natural size.] Ries I, Jegarae (dezalap)) (ago in. Bos VOR Ike MNO 2 Capac Seco codecs sdecsssesoccesesescosse 60 Exterior of somewhat imperfect and worn left valve; altitude 75 mm. Miocene, Carrizo Creek district, San Diego County, Cal. (M. P.) Fig. 2: Pecten (Patinopecten) dilleri Dall. U.S. N. M. 164846. Cotype -:----.-----.--------- 62 Exterior of imperfect right valve; altitude (restored) 180 mm. Upper Miocene or lower Pliocene, Eel River, Humboldt County, Cal. (M. B.) TGetoa pecten) ((OAlamys) ees peensis vals tens Verne) yeas me lyip Caer ae eam eee = 69 Exterior of right valve, anterior ear missing; altitude 46 mm. Vaqueros sandstone (lower Miocene), Lynch’s Mountain, Monterey County, Cal. (M. B.) EGS aA SAM eNSPECIMEM AN dip: Sis se eye rae ear e eaaee al eoe eeleraree 69 Exterior of left valve, anterior ear missing. (M. B.) Ise, Hos Haas spore APS, BO) oo nseases sae mee dodocnacssoonce ses Seon chooreoseocsssscarccs 69 Profile of both valves as viewed from the rear. (M. P.) 154 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. V MIOCENE PECTENS. Pa Aen Viale MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page. Bie: 1h) -Pecten)|((Pecten)Wkeepums isp», DL AG Ulyper sooeaoeene sacra es aenee eee eee ee 60 Exterior of right valve; altitude 75 mm. Carrizo formation (Miocene), Carrizo Creek district, San Diego County, Cal. (M. P.) EGE iG Samer specimen sas pin Oe Ul ye ata epee eee epee ea aaa 60 Profile of right valve viewed from rear. (M. P.) Bigs 22) Pecteni(tPatinopecten) | coosensis ms liumiercl.) Weiss Ne Mee 07,00 Mcrae ester eee ee 61 Exterior of left valve; altitude 103 mm. Empire formation (Miocene), Coos Bay, Oreg. (M. P.) 156 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. VI MIOCENE PECTENS. Ie Ja eld, We bal MIOCENE PECTENS. {Unless otherwise stated all figures are approximately natural size.] Jel, tl, Jeeqaraps (UReticeyazeta)) (Ko RTE ODIMENCL We On ee aacenccescncaaccossscecoecccesenaae 64 Mold of interior of right valve, showing a portion of the umbonal area and ears; altitude 90mm. Astoria formation (Miocene), Astoria, Oreg. (T1.) Fig. 2: Pecten (Patinopecten) coosensis Shumard. U.S. N: M: 10779) -.-.-2-.:.------2.------- 61 Exterior of right valve, anterior ear slightly broken; altitude 103mm. Empire formation (Miocene), Coos Bay, Oreg. (M. P.) BiLGii2 OF SAME SPECIMEN AS Ua (OS. vs San eee oe SO 2g ae ey care lee oe eerie ee ea efor eet ee 61 Profile of both valves, viewed from rear. 158 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. VII i} Ny x cat ag, MIOCENE PECTENS. Fig. Fia. Fic. Fic. Fig. Lice 1. Pecten (Patinopecten) oweni n. sp. U.C. Type Jeb ya ane 1 WDIEI, MIOCENE AND PLIOCENE PECTENS. {Unless otherwise stated all figures are approximately natural size.] Iixterior of right valve, anterior ear slightly broken; altitude 85 mm. (Upper Mio- cene?), Foxin’s ranch, Santa Barbara County, Cal. la. Same specimen as fig. 1 Exterior of left valve. 1). Same specimen as fig. 1 GYEBBS) Profile of both valves viewed from rear. (M. ? 2. Pecten (Chlamys) sespeensis n. sp. C. 8. M. B IP) Portion of mold of interior of right valve; altitude 50 mm. Miocene), Sespe Canyon, Ventura County, Cal. (M. B.) (M. B.) Vaqueros formation (lower Portion of mold of interior of left valve. 3. Pecten (Chlamys) sespeensis n. sp. C. 8. M. B. Plastoty pe Cast of exterior of slightly imperiect left valve (young); altitude 18 mm. Same locality as fig. 2. 160 (M. B.) U. S. GEOLOGICAL SURVEY ; PROFESSIONAL PAPER NO. 47 PL. VIII 424 MIOCENE AND PLIOCENE PECTENS. Fic. Fig. Fic. Fic. Jes ah 1; IE Oe. MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] 1. Pecten (Patinopecten) propatulus Conrad, U.S. N. M. 3558. Cotype.----------------- Exterior of portion of right valve; altitude 100 mm. Astoria formation (Miocene), Astoria, Oreg. (M. B.) Va: Same specimen and! valvevas! figs WS 2222. 22 ee inl wna Portion of disk, showing part of two ribs and included interspace, x 3. (M. B.) by Simin Gomecind Gh sates qlee = ope ekeomencan > ssosceesoscccsasers seoesoeseasosccoonsoce Exterior of portion of left valve. Jossame specimen asm Ly Lest vellive ess ate yaaa eee eel Portion of disk, showing part of three ribs and included interspaces, x 3. (M. B.) 162 Fic. Fia. Fie. Fig. Fic. Fia. Fia. Pay PACH exe MIOCENE AND PLIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size. 1. Pecten (Chlamys) fucanus Dall. U.S. N. M. 164933 Exterior of imperfect right valve; altitude 83 mm. Miocene, coast of Strait of Juan de Fuca, east of Clallam Bay, Clallam County, Wash. (M. B.) 2: Pecten (Chiamys) fucanus Dall, U.S: N; M. 1077905 Plastotype 2222-22222. -2-—--.-=- Cast of exterior of left valve; altitude 81 mm. Same locality as fig. 1. 2am SAMERS PECUMNE NAS ell Peer eee aerate ieee eine ieee ieee eae ee es Profile of left valve viewed from front. (M. P.) 3. Pecten (Chlamys) wattsi var. morani n. var. U.S. N. M. 164929. Type Exterior of imperfect right valve; altitude 63 mm. Lower Pliocene, Moran’s place, Priest Valley, Monterey County, Cal. (M. B.) 4. Pecten (Chlamys) wattsi var. morant n. var. U.S. N. M. 164929. Cotype-..-----.-.--- Exterior of imperfect left valve; altitude 59 mm. Same locality as fig. 3. be ePecten (Chlamys)inatisn vans monany me var U-iS. No IM 1164929)5 5555s ee eee eee Exterior of imperfect left valve; longitude 41 mm. Same locality as fig. 3. GapePecterua COTATI 8) auc ees as iy 1700 TOLIUU LN canes eee Exterior of imperfect left valve (young); altitude 30 mm. Same locality as fig. 3. 164 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. X MIOCENE AND PLIOCENE PECTENS. Pale A teeBh, Xa, MIOCENE AND PLIOCENE PECTENS. (Unless otherwise stated all figures are approximately natural size.] fae i, Jat (Chama) Matin in, Bos Chiko Sh WS sosssosscussocenoass sdosocensesouesaao 120 Exterior of slightly imperfect left valve; altitude 66 mm. Lower Pliocene, Kreyenha- gen’s ranch, Fresno County, Cal. (S.) Ibis ek Senne Seceansen ge wis, We os see sco seed boncbn soos bo 5SSSecocoasessoesss 2 Se tat 120 Profile of left valve, viewed from rear. (M. P.) Hies-2) -Pecten (Chiamys) hamlinumesps WaiSs Ne ME 6484459 Type sees eee ae 67 Exterior of contorted (lengthened) right valve; altitude 50 mm. Miocene (lower?), head of Slacks Canyon, Monterey County, Cal. (M. B.) Then, BY eaiiO (CaO) mattarein Eloy WD dle AYO Se once gcse océoaeocnshe sbenncosencescecor 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.) Wines eo ewan. (TIE) waitress (Ce SHON 1s WANE (Clothe G oe ssc e es ecee see csocooses 67 Exterior of slightly imperfect left valve; altitude 63 mm. Lower Pliocene, Kreyenha- gen’s ranch, Fresno County, Cal. (M. B. ) Iie, Clay, (Sehoalsysjeterehmo(cyal Asbo ACES ee ern gene aa Sapa eS aeoneooNSeocec Goss Soonesesreosescemesc 67 Profile of left valve, viewed from rear. Fic. 5. Peeten ( Lyropecten) crassicardo Conrad var. hamiltoni n. var. U.S. N. M. 164845. Type. 73 Exterior of slightly contorted and imperfect right valve; altitude 40 mm. Miocene, Alum Rock Canyon, Santa Clara County, Cal. Fic. 6. Pecten (Lyropecten) crassicardo Conrad yar. hamiltoni n. var. U. 8. N. M. 164845. (OKs 55 cen aoto tee cuoeeseS ANAS Sep Ie enone n Sadan saboepoascesadaa acces access Exterior of imperfect (earless) right valve; altitude 63 mm. Same locality as last. =] 166 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XI MIOCENE AND PLIOCENE PECTENS. al \ yr ee eA Eee MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page. Ings Mo Jerre (Wonaacdian). (OED We os WHS AI eo censacoscone secs oaosocenesseeosesee 70 Exterior of slightly imperfect right valve; altitude 150 mm. Miocene (lower), Santa Inez Canyon, Santa Barbara County, Cal. (M. B.) lite, Be, WAydiaD. (UapiRaatara)) COORD. Wego, IDS Noon edeossteneos- soles se nsossecessSseuscesds 70 Exterior of umbo and ears (the anterior somewhat imperfect) of a right valve; hinge line restored 86 mm. Miocene (lower), Santa Monica Mountains, Ventura County, Cal. (es) 168 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XII MIOCENE PECTENS. > A 7 Pale AGS es 2Xealeiale MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] ies Np Jeaeiae (Venmeaddo) Womgase in, So WCE INAS scene sceoomer sas sccesceooeuneasaosesaac Exterior of left valve, ears impertect; altitude 150 mm. Miocene (lower), Santa Inez Canyon, Santa Barbara County, Cal. (H.) HiG-las Names pecimentastig: 1 jc sae eae a ee eee een ee eine a seas REE eee Profile of both valves viewed from rear. (M. P.) 170 PROFESSIONAL PAPER NO. 47 PL. XIII U. S. GEOLOGICAL SURVEY MIOCENE PECTENS. PAN Xeleve MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page. ies Me Veer (Sinpedeiam) yacinaioo ite yoy MRIS dia We Abe oo sose scene. Saa-secasseesneceece 80 exterior of imperfect right valve; altitude 150 mm. Vaqueros sandstone (Miocene), between Morro and Toro creeks, San Luis Obispo County, Cal. (M. B.) Rig: la:ssamerspecimen as fig. ll <5. sees ac eae Moe ae ia Roe eee oe eee ae eee 80 Profile of both valves viewed from rear. (M. P.) 72 PROFESSIONAL PAPER NO. 47 PL. XIV U. S. GEOLOGICAL SURVEY MIOCENE PECTENS. EAI boca Nd OC WE MIOCENE PECTENS. (Unless otherwise stated all figures are approximately natural size.] Page. Iiges le Lage. (Chopra yediap)) janie (os Wyte dia Wh AWS 2 a2 ee cs ec se es coc So sw esoase= 80 Exterior of imperfect left valve; altitude 150 mm. Vaqueros sandstone (Miocene), between Morro and Toro creeks, San Luis Obispo County, Cal. (M. B.) Fig. 2. Pecten (Plagiocteniwm) neahensis n. sp. U.S. N. M. 5912. Type ....--.----.-------- 87 Exterior of imperfect right valve; longitude 49 mm. Miocene, Strait of Fuca, east of Neah Bay, Clallam County, Wash. (M. B.) Fic. 2a. Same specimen as fig. 2.-...-- bac) eaten sen Sees Bre hn oe eee ee eee See 87 Exterior of imperfect left valve. (M. B.) Tie, Pe, (SaheaVs) (e\peusalsioy GE) wale = occas ano aa ocoes pee] ese ces ooL aoe seed cho oese Eades seens 87 174 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XV MIOCENE PECTENS. eke Wek; XoWVe Te MIOCENE PECTENS. {Unless otherwise stated all figures are approximately natural size.] Page. Fic. Wl. Pecten (Lyropecten) crassicardo\Conrad. U.S. N. M. lo4lo4 -..--.2:---2--2..2.------- 71 Exterior of slightly imperfect right valve; altitude 155 mm. San Pablo formation (Miocene), Kirker Pass, Contra Costa County, Cal. (M. B.) IG, Hiei, Sen pocorn Eryn, We 2655 K eae toaas Seine goSdos coomossese socc imanoS escacas0 71 Profile of right valve viewed from rear. (M. P.) 176 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XVI MIOCENE PECTENS. Pale sade Bie xO Varlullee MIOCENE PECTENS. {Unless otherwise stated all figures are approximately natural size.] Page. Fic. 1. Pecten (Lyropecten) crassicardo Conrad. U. C Exterior of shghtly imperfect right valve; altitude 97 mm. Miocene), Contra Costa County, Cal. (M. B.) Fig. lv. Same specimen as fig. 1 San Pablo formation (upper SR are ere Ee i ae 71 Exterior of imperfect left valve. (M. B.) Fic. 1). Same specimen as fig. 1 View of both valves from the rear, showing constriction of disk. 178 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XVIL MIOCENE PECTENS. Fia. Fic. Fia. > mh a Ta Jeg Deva hh SOE EIT IL MIOCENE PECTENS. {Unless otherwise stated all figures are approximately natural size.] I. ‘Pecten\(Tajropecten) crassicardo Conrad. A. N.S., Phila: ‘Type -22-----:----_-2------ Exterior of left valye (ears gone); altitude 135 mm. Miocene (probably upper, or San Pablo formation), ‘‘California.”’ (Photograph by Ralph Arnold. Shell not coated.) 2. ecten) (ynopecten) crassicardo) Conrady (CliS! Mi Ba d272eee eee nee eee eee se Exterior of left yalve (ears gone); altitude 88 mm. Miocene, Ventura County. (S.) 2a. Same specimen as fig. 2 View of both valves from the rear, showing constriction of disk. (M. B.) 180 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XVIII MIOCENE PECTENS. Pe eAe an Br” sXe sXe: MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page Fie. 1. Pecten (Iyropecten) estrellanus Conrad. U.S. N. M. 164851 .............-...---.... ei 74 Exterior of left valve; altitude 97 mm. Santa Margarita formation (upper Miocene), Wildhorse Canyon, Monterey County, Cal. (M. B.) inc. ila, Sipe soeennem aay wes, We L520 eae canoes saoeSsae So ocadeSacocassesense ts obasesecs 74 Interior of left valve. (M. B.) 182 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XIX MIOCENE PECTENS. JID AAP DS OCC MIOCENE AND PLIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page. Vic. 1. Pecten ( Lyropecten) estrellanus Conrad. U.S. N. M. 13317. Cotype---..-.-..----------- 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.) Fic. 2. Pecten (Lyropecten) estrellanus Conrad. C.S. M. B:12871 -....-.-..--.-....----------- 74 Exterior of very convex right valve (form described as P. volaformis Conrad); altitude Timm. San Pablo formation (upper Miocene), Coalinga, Fresno County, Cal. (M. B.) die, Mor, TSN XAG O NARMS, Pe seen as Sesceoeceonteseeeaocsocuesess Sococsenstseasnc 74 Profile of right valve viewed from rear. (M. P.) BiG. 3: Pecten estrellanus Conrad var: catalinem. var, DAS Dypesss----2--5- 222] 76 Exterior of imperfect right valve; altitude 68 mm. Upper Miocene, near Isthmus, Santa Catalina Island, Los Angeles County, Cal. (M. B.) Ich, Bie, Sihak® peor Aes Be oe oo aco ono nes soe osdonmas nossa soeseseee socom onodas tfadeesors 76 Profile of right valve viewed from the rear. (M. P.) Era: 4. Pectenestrellanis Conrad var, catalinem. vary Ds A= 2222 5222. ee anne] =] een 76 Interior showing umbo and hinge; hinge line 30 mm. Same locality as fig. 3. (M. B.) 184 PROFESSIONAL PAPER NO. 47 PL. XX U. S. GEOLOGICAL SURVEY MIOCENE AND PLIOCENE PECTENS. Fic. Fie. Fia. Fic. Fig. Fic. aE Aen exe MIOCENE PECTE xGle INS. [Unless otherwise stated all figures are approximately natural size.] 1. Pecten ( Lyropecten) estrellanus Conrad. C. 8. M. B exterior of right valve (ears imperfect); altitude 7 Miocene), Coalinga, Fresno County, Cal. (M. B. 7mm. ) San Pablo formation (upper Naas Same Specimen! asi ties sll seater sete oe ee et eae at eee Exterior of left valve (ears imperfect). (M. B.) 1}. Same specimen) as fig. 1 -2--.------- 22-2 2 View of both valves from the rear, showing constriction. (M. B.) 2. Pecten (Lyropecten) estrellanus Conrad. J. H. W- Exterior of right valve (ears slightly broken); altitude 60 mm. Mountains, 40 miles east of Paso Robles, San Luis Obispo County, Cal. (M. B.) 2a. Samevspecimen as fig. 2 22222 === eee eee Exterior of left valve (ears slightly broken). 2b. Same Specimen! as) figs:2 s225---2-------- Profile of both yalyes viewed from rear. 186 Miocene, Cholame PROFESSIONAL PAPER NO. 47 PL. XX! U. S. GEOLOGICAL SURVEY MIOCENE PECTENS. Teale AY Ale ONG NO SS MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page. Ries Ie Pecten (ymomecten) mr quelenstsicae Sy sym lyh Cray a yay) © meters esr este rere 79 Exterior of somewhat imperfect right valve; altitude 110 mm. Miocene (lower), San Miguel Island, Santa Barbara County, Cal. (M. B.) Pug. ila. Saniverspecim emniias tig. a ac eee eee carat at tan rata eeslalerasoalate eel ve etetee see Bae 79 Exterior of somewhat imperfect left valve. (M. B.) Pree iSame specimen jas figs Wh. 2 Hee. ee oe ee erase wees s Sree eye ern Sarees er ere ele are pays ee ayers ee 79 Somewhat distorted profile of both valves viewed from rear. (M. P.) i8s PROFESSIONAL PAPER NO. 47 PL. XXII U. S. GEOLOGICAL SURVEY MIOCENE PECTENS. De Eyed Melby o@ os EEA, MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Dich, tl, Jaa (Wogpeostarany) AG MALSE 6 Shee | Wie Sb ING GRIN) 2552 soon en spo eesessesennos- 79 Exterior of umbonal region and imperfect ears of left valve; altitude of fragment 76 mm. Copied from drawing by Doctor McConnell. Miocene, Santa Inez Moun- tains, Santa Barbara County, Cal. Fig. 2. Pecten ( Lyropecten) estrellanus Conrad yar. termimus n. var. U. ©. Type--------------- 77 Exterior of right valve; altitude 70 mm. Santa Margarita formation (upper Miocene), Monterey County, Cal. (M. B.) AG 2a SAM ers pPeClM eM AS iO Naf eee me are aerate Pe er ere eee) eee ayes eet etererera v7 Profile of right valve, viewed from rear. (M. P.) Bigsio. Peclen | (inyropecten) vaughant i. Sp.) iD tas ype sess sss = See ee ee ee $1 Exterior of right valve; altitude 37 mm. Miocene (lower), Ojai Valley, Ventura County, Cal. (M. B.) BGS SOs SAM SNSPECUMEM! (ASML Be 2 ea evar a telethon ote eee eee or te 81 Exterior of left valve. (M. B.) BirGrgUs same SPECIMEN’ AS mig tO) oes oer seen Semen tele Beet pe eet le oe eee 81 Profile of both valves, viewed from the rear, showing contraction of disk. (M. P.) re. 4. Pecten'(Propeamusium)) stanjordensis: masps D> VAC) Wvipene asses == eee eee 91 Mold of interior of right valve and cast of exterior of left valve; altitade 7 mm., >< 3. Miocene, Burke ranch, near Stanford University, Santa Clara County, Cal. (M. B.) Fie. 5. Pecten (Pseudamusium) lompicoensis n. sp. U.S. N. M. 164931.-.................-.-. 89 Mold of exterior of contorted left valve; altitude 14 mm., x 3. Miocene shale, head of Lompico Creek, Santa Cruz County, Cal. (M. P.) 190 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XXIII MIOCENE PECTENS. al eAea hig XeOXeaE MIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Fie. 1. Peeten (Lyropecten) magnolia Conrad. U. Exterior of right valve (anterior ear missing), altitude 145 mm. Vaqueros formation (lower Miocene), Ojai ranch, Ventura County, Cal. (S.) Fic. 2. Pecten (Lyropecten) magnolia Conrad. L. 8. J. U ..--.-- Exterior of umbonal region and ears; hinge line 95 mm. Miocene (lower), between Morro and Toro creeks, San Luis Obispo County, Cal. 192 Pare. PROFESSIONAL PAPER NO. 47 PL. XXIV U. S. GEOLOGICAL SURVEY MIOCENE PECTENS. ee ASAI XCeXGNVE MIOCENE PECTENS. (Unless otherwise stated all figures are approximately natural size.] Page Fie. 1. Pecten (Lyropecten) magnolia Conrad. U.S. N. M. 13325. Cotvpe ........-.-..-..--- 77 Exterior of valve, 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 ( Plagioctenium) cerrosensis Gabb var. mendenhalli n. var, U. S. N. M. 164849. DV PO' ayaa soe ss 5 ae See 2 EE ce ae ae Ee Be Se ee he Ee Ee RE OIE S4 Exterior of right valve; altitude 43 mm. Miocene, Santa Rosalia, Lower California. (M. B.) Bre. 2a. xSamejspecimenjas ig: 2). o. see jes cee s Sec cio-ne ae ae eee er eae a ye ae eres 84 Exterior of left valve. (M. B.) BrGs 2b:, ‘Sameispecimen;as digs 2): Jeo) easton ss ee cerca sat eine eee te aisees ee eee 84 Profile of both valves, viewed from the rear. (M. P.) Fig. 3. Pecten (Plagioctenium) eldridgei n. sp. U.S. N. M. 164850. Type .-.....-.---_-----.-- 87 Exterior of left valve; altitude 20 mm. San Pablo formation (upper Miocene), McKit- trick district, Kern County, Cal. (M. P.) IGS SGsy SAIN (SPECIMEN ASN! Sierras is eons eee ete eee «mises se eee ee ee 87 View of interior of left valve. (M. P.) BrGio0 psi ey Specimen "as igs (3. Exterior of imperfect left valve, altitude 110 mm. Same locality as fig. 1. (M. B.) 204 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XXX PLIOCENE PECTENS. PLAT H XxX XT. PLIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size. The light in these two figures comes from the right-hand side, Photographs by Ralph Arnold,] Page. Wiraev lee Recien (erecien) moeuus: GONTACG meAS ING so.5) hia G60 Senos eee ec ee ae eee 95 Exterior of right valve of Gabb’s Janira bella; altitude SO mm., x 4/4. Pliocene, Santa Barbara, Cal. Fie. Ja. Same specimen as fig. 1 95 Exterior of left valve, x 4/4. 206 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XXXI PLIOCENE PECTENS. rly y a 7 IGA S18, SC SCNT IL, PLIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] le, ale Jap (Udi) Baers IWEME, “Wis SINS WG WES os ooo see coc oc oscososescouasosaces 100, Exterior of right valve; altitude 87 mm. San Diego formation (Pliocene), Pacifie Beach, San Diego County, Cal. (M. B.) Iigeig lle tee yeavents| oetalewvsy etsiaaten Ihe ee eS Ae eee peers esas snare enece pomosedm=soeedcuees 100 Exterior of left valve. (M. B.) 208 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XXXII PLIOCENE PECTENS. Fic. Fic. Fig. Fic. Fic. Fic. Fig. Fig. Fie. Fig. EME PACA exe Xee NOMI PLIOCENE AND PLEISTOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page. 5 JARHITO (CAAA) COGEIED Wo Gyo, WO, IN, Aiea ccesaqucnosasocascusesenacssSouesateeces 100 Exterior of imperfect right valve; altitude 68 mm. San Pedro format on (Pleistocene), San Pedro, Los Angeles County, Cal. (M. P.) ae Sanve.specimen vas: fips ali: 530 oe coer sere ae Sine Sey eee Ge eae ers ae 100 Profile of right valve as viewed from the rear. (M. P.) Dem CGLE TIM (OLECLETD) IM CULL TLIS1/0 ST wr [0 ey Cr) lV Ll SS Ly 1 enn mA O4 Exterior of imperfect right valve; altitude 46 mm. Pliocene, Puente Hills, Los Angeles County, Cal. (S.) Zdse SAMIe. SHECIMENKAS ANE NA atts Ss sos atk eee oy ae eens =H eieien See ee See eo eeeee 94 Profile of right valve as viewed from the rear. (M. P.) 3. Pecten (Pecten) hemphilli Dall. U.S. N. M. 7943. NBYIDOz toe eens Se eee Se ee 97 Exterior of right valve; altitude 57 mm. San Diego formation (Pliocene), Pacific Beach, San Diego County, Cal. (M. P.) soasamerspeciimenyasntig!.(3-- case sae eases osc e eee eee eee 97 Exterior of left valve. (M. P-.) 35.7 Sam eyspecinen sas Dpii3: secs. s ork seme ere eae One oe See ee ee eee ee 97 Profile of both valves as viewed from the rear. (M. P.) Am Rictena(eeecten)leconicin. sp. 1D) AGe My pee ae eer mee a a eee Seer 98 Exterior of right valve; altitude 59 mm. Pliocene, Cerros Island, off Lower California. (M. B.) 4acsame: specimen as: fot 4 aS poem 2 ee en ec eye ae rasp a ae eee es en 98 Exterior of left valve. (M. B.) 4b: Samerspecimen\ag: few Ae = << eee Sek re ee eae a en = a 98 Profile of both valyes as viewed from the rear. (M. P.) 210 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XXXIII PLIOCENE AND PLEISTOCENE PECTENS. JIN ADD, DCO OIL VS PLIOCENE AND PLEISTOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.) EIGiey Lee CCLETIN (@ Ene CLEND) NOG CLES TT eS YO Sama Ceca =m CO COLA VY eee 100 Exterior of slightly imperfect left valve; altitude 74mm. Pleistocene, Ventura County, Cal. (S.) BiG 2 PeCLETUA (CRECLETE) ONL UM YUNA EES) oy excuse HIN ae sca OL GV 94 Exterior of left valve; altitude 36 mm. Pliocene, Puente Hills, Los Angeles County, Cal. (S-) Pies 2a. Sane: specimenasifigt.2). 5. 8 Soo cag tse nes Sao eee ee Sea Se eee 94 Profile of left valve as viewed from the rear. (M. P.) Bictron el ectenn Chatimnopecien)) punisiMGensts ers pret) sean yi Cle See tee eee 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.) Mie Gh Jaap (Jeter pipes So Ws dis Wo (My ssbsconsoscsccseeeseesoesesce Exterior of a portion of the disk of a left valve. Pliocene, Tomales Bay, Marin County, Cal. 106 212 U. S, GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XXXIV PLIOCENE AND PLEISTOCENE PECTENS. lee) Baty P10) OX OG ONG PLIOCENE PECTENS. {Unless otherwise stated all figures are approximately natural size.] Page. BiGe le ects VRaLinopecten))| PUTISUTeaens isin Le Sp 1D) eA Cues 1) Cpe ete re reer ee 105 Exterior of a slightly imperfect right valve; altitude 123 mm. Purisima formation (lower Pliocene), north of the mouth of Pescadero Creek, San Mateo County, Cal. (M. B.) HG. le.e Same specimentas: fet, ds. 55 ae Tee eee ee ene at Se See ee 105 Profile of both valves as viewed from the rear. (M. P.) loch, Be Jeeta (Ieeticayzatao)) Ma Mets Mn Se Vo Wie AINR —. 2- o e sceaso- scence seecesce= 106 Exterior of an imperfect right valve; altitude 65 mm. Pliocene, Tomales Bay, Marin County, Cal. (M. B.) RIG sos ehecten™ (Ratimonecten)) luninier vans Sp ie laen sete 1 eae CO .LY, Carne 106 Exterior of a portion of a right valve showing sculpture; altitude of fragment 48 mm. (M. B.) 214 PL. XXXV PROFESSIONAL PAPER NO, 47 U. S. GEOLOGICAL SURVEY PLIOCENE PECTENS. IEA 13) OX ONCE IU: PLIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Erg. lin ecten\((Patinopecten) healeyi ne sp. Uais. Ne ME Lovl625 (Cotypelsae sna ssee eee 103 Ixterior of left valve; altitude 141 mm. San Diego formation (Pliocene), Pacifie Beach, San Diego County, Cal. (M. B.) Fic. la. Same specimen as fig. | 3 Profile of left valve, as viewed from the rear. (M. P.) 216 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XXXVI PLIOCENE PECTENS. desl Bypata beldy SSC COVIMIL PLIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page Brewis Pecten (Paiinopecten) healey neisp) WW. iS. iN: Me 1480125 Dypes=- 222522] oes eee ee 103 Exterior of right valve; altitude 121 mm. San Diego formation (Pliocene), San Diego County, Cal. (M. P.) hiGalias Same) specimen! asihry dl SPs se ee et ee Ee ee aac ae eis Ta eee 103 Profile of right valve, as viewed from the rear. (M. P.) Ite, BA, JAAN Aindna Aare) (NCO, ins oy, IDs toro caocsocdncsssococcssesocunsscodeaeece = 103 Exterior of a portion of right valve; hinge line 50 mm. Purisima formation (lower Pliocene), near San Gregorio, San Mateo County, Cal. (M. B.) 218 PROFESSIONAL PAPER NO. 47 PL. XXXVII U. S. GEOLOGICAL SURVEY PLIOCENE PECTENS. IPG eA WB; XeDe eV sis: PLIOCENE AND QUATERNARY PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page HiGale wPeciens Catia pectel) | COUTTS) Gr OCLC mee) SrA ts ee eee 101 Exterior of right valve; altitude 105 mm. Pliocene, Deadman Island, Los Angeles County, Cal. (M. B.) rie} la. Same:specimen as fig. J.1...2 25-2 aeree Jae sane oes ee ee ee ee ee ee 101 Exterior of left valve. (M. P.) Bie. dog same:specimen as wie Wl eco. ance ee aoe ee ele eee rae ee erie ne een eee eee 101 Profile of both valves, as seen from the rear. (M. P.) 220 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XXXVIII PLIOCENE AND QUATERNARY PECTENS. Fic. Fia. £ Fig. 3 Fia. Fig. 1 JEM BA ALR | OSC DOO IED, PLIOCENE AND QUATERNARY PECTENS. [Unless otherwise stated all figures are approximately natural size.] Pecten (Patinopecten) caurinus Gould. Pliocene, San Raphael Hills; Santa Barbara County, Cal. Peeten (Patinopecten) caurinus Gould. Wa Si Ni ME S833 esc Soe ee antes ares are oeicee Exterior of imperfect right valve of type of Conrad’s Pecten meekii; altitude 154 mm. AGING Sb hilaeeee esas (M. P.) Exterior of right valve of type of Conrad’s Pecten heermanni; altitude 62 mm., x } Pliocene, Santa Barbara, Cal. Photograph by Ralph Arnold. (M. B.) Pecten (Plagioctenium) paucicostatus Carpenter. U.S. N. M. 156346. Type - Exterior of right valve, anterior ear broken off; altitude California. _(M. B.) SO SAMeTSPeClMeN AS MCA Osa ee eee Profile of right valve as viewed from the rear. (M. P.) 4. Pecten ( Plagioctenium) paucicostatus Carpenter. Exterior of left valve; altitude 35 mm. 99 32 mm. Recent, Gulf of Same locality as fig. 3. U.S. N. M. 15634b. Cotype (M. P.) Fage. 101 101 137 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XXXIX PLIOCENE AND QUATERNARY PECTENS. Eel Aww ah Xe PLIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size. The light in these two figures comes from the right-hand side. Specimen not coated by Williams process. Photographs by Ralph Arnold.] HA GemllempEAeCLeTUN CMOGAECLETH MECLCLULIA Gxe)1D 10 sume Olen Cm ny 10 eet 106 Exterior of right valve; altitude 130 mm., x }}. Pliocene, Cerros Island, off Lower California. (M. B.) Richalas Samer specimen as igo dl) 2 cee oe = la ae one Cees eee mt ene ee ee eee ee eee 106 Exterior of left valve. (M. P.) 224 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XL PLIOCENE PECTENS. Fia. Fie. Fia. Fic. Fia. Fic. Fic. Fic. Fic. Fic. ten JEU) IE 1, SC Ball, PLIOCENE AND QUATERNARY PECTENS. [Unless otherwise stated all figures are approximately natural size. ] 1. Pecten (Chlamys) parmeleei Dall. U.S. N. M. 154479. Type----.---- ORR cate Copied from Doctor MeConnell’s drawing of left valve; altitade 45 mm., * 5/4. (Trans. Wagner Free Inst. Sci., vol. 3, pt. 5, pl. 37, fig. 14.) San Diego formation (Pliocene), Pacific Beach, San Diego County, Cal. Gi tH MENGLoCOuenerl EVs Motes dl Oe Se SSe nape oe osRoosadaonecdb es seecdsoou sone EasuedersdH Se Copied from Doctor McConnell’s drawing showing detail of secondary sculpture highly magnified. (Jdem., pl. 37, fig. 14a). OF Vota (Cite) Crariae IONE (Win tsb Nig NL, MMOgigPs Aye se. cece sesh see Copied from Doctor McConnell’s drawing of right valve; altitude 331mm. (Trans. Wag- ner Free Inst. Sci., vol. 3, pt. 4, pl. 29, fig. 6.) San Diego formation (Pliocene), Pacific Beach, San Diego County, Cal. By 1egdta CC Giilen nos) (atennara noi s)0— Wa TS INo NUNS MGHCEIG | Asso ooo tags oes sssesecenes- Exterior of portion of disk; altitude 55 mm. Pliocene, Crescent City, Del Norte County, Cal. (M. P.) 4, Pecten (Chiamys) hastatus Sowerby. U.S.-N. M. 13350) .............--.-:.------.---- Exterior of left valve of Conrad’s type of Pecten altiplicatus; longitude 55 mm. Pliocene, San Raphael Hills, Santa Barbara County, Cal. (M. B.) ay Lege ((Chollan nen) gacimincah IDE WLS “Wi, Sip ISis WIG WMG oe eee ease eee ese seeec ace Exterior of slightly imperfect right valve; altitude 70 mm. Pliocene, Crescent City, Del Norte County, Cal. (M. B.) Doms cam eyspecimenkasuhl gro. aera ee sa ee eee ee es eee ele = ee eee ae eee Profile of right valve, as viewed from the rear. (M. P.) (i Joico (CHUTE) (YAU Monp Meni toe, So, Da ty AW fee) coos nae cooscesedcoseconaeao-soc Exterior of right valve (anterior ear slightly broken); altitude 18 mm., * 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:) --...-..........---..-.-..- dis, Sane} SPECIMSNvas nie NG. - 5 Sejele eee setae eae san eels See eyeeleteie ee efatele steie et= eerste (orale ee eee Exterior of left valve, x 3. (M. B.) fia. Sameispecimen'and yalveiasitic® 7, maturalisize. (MRS) S225) 222 sees eee ee 226 119 118 107 108 119 119 108 108 108 108 PROFESSIONAL PAPER NO. 47 PL. XLI U. S. GEOLOGICAL SURVEY PLIOCENE AND QUATERNARY PECTENS. Page Ah xe ae PLIOCENE AND QUATERNARY PECTENS. [Unless otherwise stated all figures are approximately natural size. The light in these figures comes from the right- hand side. Photographs by Ralph Arnold.] Page. Ties, al, ezaiae (CCID). Tain Wroywerdohy, Wile Wr 18}. 2-56 5 eso seco sss sbessecesusssssscess 108 Exterior of right valve; altitude 59 mm. Recent, Monterey Bay, Monterey County, Cal. je. Jif. Senne Serolmaern Gry Jit, We 55555555 55555555 oss coo conse ose ssedsscesrscss Saessesce> 108 exterior of left valve. EMG eso eeecteny ORLEINYS))) LASERS SO WELD iyey Elen Missy 15 eee a eee een ee aot re 108 Exterior of right valve; altitude 49 mm. Same locality as fig. 1. Btvely Oren, Sewaarey Gporerouneverny ENS} 30 2) os Sees eekoes coo coc ee ccenoe saeasar en sosoaneaanosooess sass 108 Exterior of left valve. HIiGeust spe PeCleren (ELAOUGCLETAULNT)) MI CUNCLLGMIS! SO WET Dyin typeset ate eet eee eee 125 Exterior of right valve; altitude 54 mm.; San Pedro formation (Pleistocene), San Pedro, Los Angeles County, Cal. ANG uA eee BEGLETEN (ISLC LOCLENVULUITU) MCUNCLULCUTSE SOIC LID Vie nt) Geena rete an eeett 125 Exterior of left valve; altitude 49 mm. Same locality as fig. 3. Fic. 5. Pecten (Plagioctenium) circularis Sowerby, equilateral variety. D. A..--..-:--------- 125 Exterior of right valve; altitude 53 mm. Same locality as fig. 3. Fic. 6. Pecten (Plagioctenium) circularis Sowerby, equilateral variety. D. A...-------------- 125 Exterior of left valve; altitude 56 mm. Same locality as fig. 3. U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XLII PLIOCENE AND QUATERNARY PECTENS. Bia. Fra. Fia. Fic. Fie. Fra. Fig. te NE NG ele lie MIOCENE, PLIOCENE, AND QUATERNARY PECTENS. [Unless otherwise stated all figures are approximately natural size.] 1. Pecten (Chlamys) hastatus Sowerby var. navarchus Dall. L. 8. J. U-......-.--.-------- Exterior of right valve; altitude 56 mm. Recent, Puget Sound, Washington. (M. P.) ar Same specimenragiion de. 538 Rac ce ec pean ae ie ese eee eae eae ARR EEC OEE ones Exterior.of left valve. (M. P.) os tSamerspecimenasuhlon Us aoe a2 teyhe nities cisjcle meee Se See eee ee eee eas Profile of both valves as viewed from the rear. (M. P.) 2. Pecten (Chlamys) hastatus Sowerby var. hindsii Carpenter. U.S. N. M. 150220_....._-- Exterior of right valve; altitude 56 mm. Recent, southeast Alaska (U.S. Fish Com. stations 2850-2851). (S.) SOs SAM OCIS PECLINEM ASE Panama = semen are oe ars Se oe SR a Se Exterior of left valve. (S.) 3. Pecten (Chlamys) hastatus Sowerby var. hericius Gould. U.S. N. M. 3881 .....-.---.-- Exterior of right valve of typical form of this variety; altitude 72 mm. Recent, Puget Sound, Washington. (M. P.) Ode AMM speci mM enyaAs Me AS). i lw kate tes Sea ee ee tae es Sone yee ete eee Exterior of left valve. (M. P.) 230 Page 112 112 112 1 111 110 110 PROFESSIONAL PAPER NO. 47 PL. XLIII U. S. GEOLOGICAL SURVEY AND QUATERNARY PECTENS. PLIOCENE, MIOCENE, Pia. Fia. Fig. Fig. Fig. Fa. Fig. Pia. Fig. Fia. Pia. Fig. Fic. Kia. Jeb vat died, Ox ALAM PLIOCENE AND QUATERNARY PECTENS. {Unless otherwise stated all figures are approximately natural size.] 1. Pecten (Chlamys) jordani Arnold. U.S. N. VDC ns eecee eee eee Exterior of right valve; altitude 45 mm. Pliocene, Deadman Island, near San Pedro, Los Angeles County, Cal. (Mem. Cal. Acad. Sci., vol. 3, pl. 12, fig. 6.) (M. P.) iets ASE ONY ChoonaneIN AAS. Ny Ml see See aeseas to see cs uEoeoSBSEb eaSnos Exterior of left valve. (Jdem., pl. 12, fig. 7.) (M. P.) 1G: qwamespecimentaswi ey lls ee eee ames e rem eae tee eerie eine ata e ee Profile of both valves as viewed from the rear. (M. P.) 2. Pecten (Chlamys) hastatus Sowerby var. strategus Dall. D. A.............-..-..-1---- Exterior of left valve; altitude 36 mm. Pleistocene, near bath house, Santa Barbara, Cal. Zila SAIN WSPCCLIMN GNU ASL Psa eee eee erate eer relates ba ne er ee ee rere Profile of left valve as viewed from the rear. (M. P.) 3. Pecten (Chlamys) hastatus Sowerby var. strategus Dall. D. A.......-.-..-------.----- Exterior of small left valve; altitude 21 mm. Pleistocene, San Pedro formation, Dead- man Island, near San Pedro, Los Angeles County, Cal. (M. B.) 4. Pecten (Chiamys) hastatus Sowerby var. strategus Dall. D. A..........-----.--------- Kixterior of right valve showing secondary sculpture; altitude 21 mm., x 38. Same locality as fig. 3. 5. Pecten ( Plagioctenium) cerrosensis Gabb. U.S. N. M. 61246 Copied from Doctor McConnell’s drawing of the left valve of Dall’s type of Pecten subventricosus; longitude 63 mm. (Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, pl. 29, fig. 8.) Phocene or Pleistocene, Ventura County, Cal. 6. Pecten ( Plagioctenitum) circularis Sowerby. F. L. B oy hl pa he earner ee Exterior of right valve; altitude 45 mm. Recent, Gulf of California. (M. B.) (Pho- tographed without coating by the Williams process. ) Gam Samejspecimen: as) igs .6i 555 jee seca 2 2s ie aeineseinse se ee eee eee ee eee Exterior of left valve. (M. B.) (No coating.) 6b. Same specimen as fig. 6 Profile of both valves as viewed from the rear, showing great convexity of the typical form of this species. (M. P.) 7. Pecten (Plagioctenium) circularis Sowerby. U.S. N. M. 61246.......-.....-....-.---- Copied from Doctor MeConnell’s drawing of the type (right valve) of Dall’s Pecten compactus; longitude 26 mm., * 7/5. (Trans. Wagner Free Inst. Sci., vol. 3, pt. 4, pl. 34, fig. 5.) Pleistocene or Pliocene, Ventura County, Cal. Ge Lauaian (WERNER OE) Guna We 05 IDS, Fi Nsscee. conasecsansaoescensearcsoess Interior of right valve, showing short internal lire; altitade 17 mm. Pliocene, Santa Monica Canyon, Los Angeles County, Cal. (S.) Sh, Jaan (Emap DO SUMO IRD 1, Gyo, WLOX, COORYNe coeonosocnsosesccesusscansscasc- Exterior of imperfect left valve; longitude 15 mm. Same locality as fig. 929 AOL 113 123 125 125 125 126 126 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XLIV PLIOCENE AND QUATERNARY PECTENS. JP Dea Oe IAN PLIOCENE AND QUATERNARY PECTENS. [Unless otherwise stated all figures are approximately natural size.) Page. Fie. 1. Pecten (Chlamys) islandicus Miller. D:. A.............------------------------------ 113 Exterior of right valve; altitude 88 mm. Recent, Banks of Newfoundland. (M. B.) Brae lla. Same specimen) as) figs Woe ssa a a ata a allele 118 Exterior of left valve. (M. B.) Fig. 2. Pecten (Chiamys) washburnei n. sp. U.S. N. M. 164843. Type.--.-..-------.-------- 119 Exterior of imperfect left valve; altitude 108 mm. Pliocene, mouth of Yachates River, Lincoln County, Oreg. (M. B.) Fie. 3: Peeten (Chlamys) lawsonin. sp. ©. A.S. Type\..-----------5--------=-------------- 117 Exterior of right valve (umbo and ears missing); longitude 65mm. Pliocene, 4 miles south of Guadalupe, Santa Barbara County, Cal. (S.) +. 4. Pecten (Chlanys) lawsontin. sp. ©. A. S. Cotype ..-.-----------------------------<- 117 Exterior of an imperfect left valve in which the umbonal region has been partially restored with plaster; longitude 34 mm. Same locality as fig. 8. (M. B.) 3} 23 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XLV UO 2 Ree Se PLIOCENE AND QUATERNARY PECTENS. Fig Ieee IN 19, Pe IL Me, PLIOCENE AND QUATERNARY PECTENS. (Unless otherwise stated all figures are approximately natural size.] . 1. Pecten \ Pecten) excavatus Anton. L. 8. J. Exterior of right valve; altitude 65 mm. Bras dace Same.specimen asia ella see oes asses sel see he ee eecisare a ecient Exterior of left valve; altitude 57 mm. (M. P.) Bice loan Sam enspecin enitas Bh Oasis serie sess eee ieee aaa ee eee ae eee ete Profile of both valves as viewed from the rear. (M. P.) Ines Wy JAadiags (Clikanop) Verona Coommrel, 1D), No noose cocoo econ scones coc sosdaseaoncosessn- Le, Fia. Fic. Fig. Fia. Bia. Fia. Fig. Fia. Fira. Fia. Fig. Fig. Fig. Exterior of right valve; altitude 25 mm. San Pedro formation (Pleistocene), San Pedro, Los Angeles County, Cal. (M. P.) 202 HAMe Specimen vag Moy 2, Seek eevee rysiereeeca Seco ee eacla ne Moe ace = ORS Se Ric a ae SATE ee Profile of right valve as viewed from the rear, showing convexity of typical form. 3. Pecten (Chlamys) latiauritus Conrad. D. A Iixterior of left valve; altitude 27 mm. Same locality as fig. 2. (M. B.) SCH SAMe RS PEC CNAs. wee ctl tpaiats aia eee stele ers aise eine ne cee seen ee eee aes Profile of left valve as viewed from the rear. (M. P.) 4. Pecten (Chlamys) latiauritus Conrad var. monotimeris Conrad. D. A .......----.------ Iixteror of right valve; altitude 20 mm. San Pedro formation (Pleistocene), Los Cerritos, Los Angeles County, Cal. (M. P.) 5. Pecten (Chlamys) latiauritus Conrad var. monotimeris Conrad. D. A_......---.-------- Exterior of left valve; altitude 22 mm. Same locality as fig. 4. (M. P.) Daasameyspecimensnas mes mtsand Omer ss sees eee eee een see eee see ee eee eee eee Profile of both valves, as viewed from the rear. Note the greater convexity of the left valve as compared with the greater convexity of the right valve in Pecten s. s. (M. P.) 6. Pecten (Chlamys) latiauritus Conrad var. cerritensisn. var. D. A. Type ..-..-.------- Exterior of right valve; altitude 24 mm. San Pedro formation (Pleistocene), San Pedro, Los Angeles County, Cal. (M. B.) 7. Pecten (Chlamys) latiauritus Conrad yar. cerritensis n. yar. D. A. Cotype Exterior of left valve; altitude 21 mm. Same locality as fig. 6. (M. P.) 8. Pecten (Chlamys) latiauritus Conrad var. fucicolus Dall. U.S. N. M. 96049 Exterior of right valve; altitude 30 mm. Recent, on kelp, off Cerros Island, Lower California. (M. P.) Sa. Samey specimen asi Me 8i45 meen soa cee. ee eee Sees eee Ree ae ee Ree eee Exterior of left valve. (M. P.) 9. Pecten (Chlamys) latiauritus Conrad var. delosi n. var. D. A. Type ...--.--.-..---.- Exterior of right valve; altitude 12 mm., * 3. San Pedro formation (lower portion), Pleistocene, Deadman Island, near San Pedro, Los Angeles County, Cal. (S.) 9a) Same specimenvas) figs 9h maturall igizeee semececas cee eee ee eee ee eae ce see ee eeeeeee 10. Pecten (Chlamys) latiauritus Conrad var. delosi n. var. D. A. Cotype Exterior of left vaive; altitude 11 mm., * 38. Same locality as fig. 9. 10a. Same specimen as fig. 10, natural size 236 Page. 134 134 134 129 129 13t 131 130 130 130 130 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XLVI AUNT ane: Sera Ay a ease Ni! Sh \ Oni) Popp \N Seog 4 “a ny \. ge, dy PLIOCENE AND QUATERNARY PECTENS. PG PACE Ene 2c 1G, Veslale PLIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page. EGrallewecectenn Cea Topeclen) nas tte epllenss|) ema sm Came) Cee eee so. ZZ Exterior of right valve; altitude 155 mm. Pliocene, Cerros Island, off Lower California. (T1.) Bret ila: Sametspeciment ase. Ue scoc ier Sees cies = cine oo Sees Ses See ee Se eee 122 Outline of both valves as viewed from the rear. (M. P.) U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XLVII PLIOCENE PECTENS. ales Ae Wie NCTE, a \Viawlee lie PLIOCENE AND RECENT PECTENS. [Unless otherwise stated all figures are approximately natural size.] Page. Iniges, We, Axe (MoainoynAHe)) GCAO We Sis Wio (On, We 5 = see seen sos sons csescesasesssc 122 Exterior of left yalve; altitude 155 mm. Pliocene, Cerros Island, off Lower California. (H1.) Bia: 25 Pecten (‘Pseudamusium) randoiphi Dall: U.S: N. M. WO77492222 2-2-2522 22 138 Ixterior of right valve; altitude 29 mm. Recent, off Destruction Island, Wash., 516 fathoms. (U.S. Fish Com. station 3343.) (M. P.) Ich, Ber, SEMMTENs oONMAGIN BI 3 PE oo a Se separ anes sone enSSS5+ 555s 54S00e sass eonsescosasens 138 Exterior of left valve. (M. P.) Fia. 3. Pecten (Pseudamusium) randolphi Dall yar. tillamookensis n. var. U.S. N. M. 150233. TN OS skeet suo Eee eee Sasori Hees st ass caPHasAB aS aceanasaser ocusscesear ore 139 Exterior of right valve; altitude 30 mm. Recent, off Tillamook, Oreg., 786 fathoms. (U.S. Fish Com. station 3346.) (M. P.) DEAL cS CoA SEUIDDE IS TO COLIN TOS LL ih Ped eo 139 Exterior of left valve; altitude 31 mm. (M. B.) 240 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XLVIII PLIOCENE AND RECENT PECTENS. Pia FCG sella Sam evs pecimenvas ih Oe lese ee Mesen eee eeesas eee eee eee er ames iae Exterior of left valve (anterior ear slightly broken). (S.) BIG wllOs Sam CGS PECIMEN AS hile le. eee eee ilo re eee eee ee tree Profile of both valves as viewed from the rear. Iie, 2A Jace (WAGranGid) aoa wi, yo ID, Wo WAY ssseccesescessueccsasbes Exterior of right yalve (anterior ear somewhat imperfect); altitude 35 mm. formation (Pliocene), Pacific Beach, San Diego County, Cal. (M. B.) 1M Bh Verein (eho enn)) Coopers Sos IDIN, COHAN ses see s- co seccscasce Exterior of right valve; altitude 830 mm. Same locality as fig. 2. (M. B.) Bia. 4. Pecten (Plagiocteniwm) cooperin. sp. D. A: Type. .:------.-=-=----------- 1 AID, OOS, PLIOCENE PECTENS. [Unless otherwise stated all figures are approximately natural size.} b leeeectens (Calagiocteniunn ncernosensis) Gab Dram Wel @=ae= eee eae Exterior of right valve (anterior ear somewhat imperfect); altitude 106 mm. Cerros Island, off Lower California. (S8.) Exterior of left valve; altitude 27 mm. Same locality as fig. 2. (M. B.) 242 Page. Pliocene, San Diego pete seen 124 Sota eee 124 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. XLIX PLIOCENE PECTENS. JP aa IES QUATERNARY PECTENS. [Unless otherwise stated all figures are approximately natural size.] Fic. 1. Pecten (Plagioctenium) circularis Sowerby yar. xquisulcatus Carpenter. OU. 8S. N. M. IV PYUBSA Rs A Se, Cena aor sodceonooe scares gheracne oo seneoSacdEEmoeuotencomeokrecass 132 Exterior of right valve; altitude 82 mm. Recent, San Pedro, Los Angeles County, Cal. (Photographed without coating to show coloration.) (M. B.) Ie eh inane yoxouontson eip sites Meet es poe oes ose seoKeade eseecaRs Nese ce San pore aeSosRoe 132 Exterior of left valve. (Photographed without coating.) (M. B.) (Die, alia, Symvacerenmean sy We, eso en epee osos coco se casos seereaascenesuTseeannsseaaegs 132 Profile of both valves as viewed from the rear. (M. P.) Fic. 2. Pecten (Equipecten) palmeri Dall. U.S. N. M. 150980. Cotype.-.-..----------- = 136 Exterior of right valve (young); altitude 26 mm. Recent, head of Gulf of California. (ISR) MiGs 2as same specimen! as figs 25s 2 =. sce ee ceil la atm = aati aaa alle ie ee 136 Profile of right valve, as viewed from the rear. (M. P.) Fic. 3. Pecten (Hquipecten) palmeri Dall. U.S. N. M. 150980. Type ..--.----------------- 136 Exterior of left valve; altitude 48 mm. Same locality as fig. 2. (M. P.) lder, Sten, Shae Faoionon We sie} 8) Geo seoadesonen = Sees dsoa doses sosesces> sce hecoesooeanooc 136 Profile of left valve as viewed from the rear. (M. P.) Fic. 4. Pecten (Pseudamusium) davidsoni Dall. 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, pl. 40, fig. 6.) Recent, Davidson Banks, north of Unalaska, 351 fathoms (U. 8. Fish Com. Station 3330). imc, Can fans Rjoetemael Ait ayes CLS Se oe) oon ae eases eae so ssoc dean aaeeae as aao eos oe one aacts 138 Copied from drawing of left valye. (Jdem, pl. 40, fig. 5.) 244. U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO, 47 PL. L QUATERNARY PECTENS. IPA PAC aia Ip ll QUATERNARY PECTENS. (Unless otherwise stated all figures are approximately natural size. ] Page. Ie, I, Jedi (Caza) Chaps IDEN We tsb Nis Wl UXO SIO, A\ (es 5 oe se Soe see a see 127 Exterior of right valve; altitude 86 mm. Recent, San Pedro, Los Angeles County, Cal., dredged. (M. P.) Pie. was jsamevspecimen- asp. I 2220.5: -eseseiease- came seers = nem eee cincmseine Sele Gem eee ecient 127 exterior of left valve. (M. P.) 127 Fic. 16. Same specimen as fig. 1 Profile of both valyes as viewed from the rear. — ( 246 U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. LI QUATERNARY PECTENS. PAs eae QUATERNARY PECTENS. [Unless otherwise stated all figures are approximately natural size.] Fig. 1. Pecten (Nodipecten) subnodosus Sowerby. U.S. J. U -..-....-.-:---.-----.---------- Exterior of right valve; altitude 112mm. Recent, west coast of Mexico. (M. B.) Fia. 2. Pecten (Chlamys) hastatus Sowerby var. albidus Dall, U.S. N. M. 150207. Type -.--- Exterior of right valve, showing broad fasciculi; altitude 45 mm. Recent, Niugliuk Harbor, Unalaska, 68 fathoms (U.S. Fish Com. station 3315). (M. P.) Bich, Pier, (Simin) Ryan CPA a nena gasonagceacace const oeee nS so upastonasccosneasuestece Exterior of left valye, showing narrow fasciculi. (M. P.) Fic. 3. Pecten (Pseudamusium) vancouverensis Whiteaves. Type .----.-----.---------------- Copied from original drawing of right valve of type; altitade 8 mm., * 4. (Ottawa Naturalist, vol. 7, pl. 1, figs. 1 and 1a.) Recent, off Vancouver Island, British Columbia. [Pies Ge tsthentes syortovenOe EC) We one s45 soeeee 5 oeeeso5 aesocosess doaoac ose cesr es cussbeccosoc Copied from drawing of left valve of type. 248 Page. 128 140 ‘my U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 47 PL. LII QUATERNARY PECTENS. Fic. Fig. Fig. Fic. Fia. PAS SoS De ARS QUATERNARY PECTENS. [Unless otherwise statec 1. Pecten ( Nod ipecten) subnodosus So 1 all figures are approximately natural size. medons, Wa Sk Uo lW! s-esseccche sen ssagcasceesccsousss Exterior of left valve; altitude 112 mm. Recent, west coast of Mexico. (M. B.) la. Same specimen as fig. 1_.--.-- Profile of both valves as viewed f 2. Pecten ( Propeamusiion) alaskensis rom the rear. (M. P.) Dall. WsSSINe ME Ws9604 S252 eee onal ners sie Exterior of right valve; altitade 22 mm. Recent, southwest of Pribilof Islands, Bering Ss Sea, 80 fathoms. (U Fish Ce ? 2a. Same specimen as fig. 2..--.- g ym. station 3602.) (S.) Exterior of left valve; altitude 25 mm. (Note difference in size of right and left valves of same individual.) (S.) 3. Pecten (Propeamusium) alaskensis Interior of slightly imperfect left Recent, Point Etches, Alaska. 250 OEE MLO SG Nay een} ee em enaato seo scams hed valve, showing internai riblets; altitude 20 mm. (S.) PROFESSIONAL PAPER NO. 47 PL. LIII U. S. GEOLOGICAL SURVEY QUATERNARY PECTENS. INDEX. {Names in italic are synonyms; figures in black-face type are of pages giving descriptions; figures in italic show location of illustrations. ] A. Acila castrensis Hinds... ..- Acmiea depicta Gould insessareimds sche eee Se See seaee Ss instabilis Gould mitra vEschscholtz{-2 ose. ate siee)-1a paleacea: Goldie. --su-sesesson. eae peliayEschseholtz).2--2=-2 20 -ssoe nese ae Spectrum. (Nuttall) Reeve .....--....2.. hey OUEMSIN Gal b Deen aaaeeet ar sete eee ee Actzon lawsoni Weaver GEES KAU DES DIAS fic iane eters aaa ater aoe A Sic aaeecateenene BeeSEB SES petedungiaeeee. Acus simplex Carpenter .....-....---.------ Admete gracilior Carpenter ..............-- JEquipecten Fischer opercularis Linné DULCE eee anes a een Esopus echrysalloidea Carpenter ........-.-------.---- opal ni Gebt 7 nto Gl eee soe See Bo aasescoe socio 35 Agasoma barkerianum Cooper ....---.---.--- 19, 73, 78, 83-8: Pacha (Gi os ao Be oeeasnooce no seoe eee =earesen 19, 78, 83 kernianum Cooper ---- 19,78, 78, 83, 84 Alaska ypecte ns Ole =n nese <= a= iar 112-114, 134, 136, 138-140 Aligena cerritensis Arnold .......-......-------------- 33 Amalthea antiquata Linné .........-.-..-.----.------- 34 | Cramioidesi@anpenten:.cqnaa- cece seers es = cele 34 MDH ONGIMEN CHA OSS Se Sees ose sce esceee a sorosos 34 Amauropsis alocata Gabb.......-.--..------------+----- 14 Amiantis callosa Conrad..............----------------- 33 Amphissa corrugata Reeve ...----..---------- 31,34 VEIT COSH PATIO G oon anemia al 34 VETSIGOLON DA lee eminent eaisieen eme 34 Ampullina striata Gabb .....-.-.---.--- Ac 12 PAVESI UIT ESO LLG ieieia's alee = laielaisit ean - 41, 50 CCU URITTAGONL Ce se anor oleae ime = inl 101 lompocenSis:--.-...--.----- 50, 73. mortoni Ravenel ....-..--- pleuronectes Linné... Anachis minima Arnold... Ancilla californica Cooper elongata Gabb ..-. Angulus buttoni Dall Anomia lampe Gray . subcostata Conrad . - (ATED OZO Beas teeter atntiaa see rls ome clei mi Arago formation, equivalents of -. 17260—No. 47—06—17 punctoccelata Carpenter ........-.-.--.- Spaapocbee 31, 84 sbesoehacas 34 neneererrs 14 19, 24, 93, 117, 120 eNemcstetalaes 12 2areasoze4 34 22 10 Pee emee 34 a eae 36 | ee 27, 34 iso e 41,49 Page Arca DilO Da WV CAlVerisese selena teen ablas omnia se serene 2 Canalis Conrad ie espercecmenie ee risemene ces 19, 24, 27, 65, 76 Morn op {C321 8) oly aS Ams poss ee Een Rebar Gaon acaue 14 la Digite Sow er bw ae eseiee ce ceteee raaeeee ems eetere erate 33 microdonta Conrad. 2-02. -c--=-cc se eeee eee 19, 24, 78, 83 montereyansa) Osmontesn esa n a= lee ee ae ae 21, 56 TONLE COSTA Laer aoisteteeete e oe eetiee 91, 95, 116, 123 irilinesta, GOmredere == aeen= eee 7,30, 100, 122 CJ Oge maces Seesror Qob CUooNS JbecepEmaaEDoS 17, 22, 51, 70, 86, 117 Architectonica ecognata Gabb as 14 horni(GabDie-sse eee ee ee woe 4 tuberculata Weaver 12 Arnold, Delos and Ralph, on stratigraphy of Califor- MI, = Ha Soa cebou ar ciuscias cage adzupEsaeD ES 2. Ashley, G, H., on Purisima formation ....-- 25, 30 Assistance, those rendering, acknowledgments to 8 Astarte branneri Arnold -- semidentata Cooper --- Asterias rémondi Gabb ..-- Astoria sandstone, equivalents of -- Astoria shales, equivalents of -.-- Astrodapsis tumidus Rémond -. whitneyi Rémond ......- Astyris californiana Gas gausapata Gould .. carinata Hinds TiChpNOreni Gab ess ecole sae ee eee ei 27, 30, 103 tuberosa Carpenterfjsasae as === -= stam oldeea nnn 19, 35 HRon ge ACESS SSbESoSSsR Ses 10 19, 24, 28, 64, 79, 83 SACS ARE Sods DOG On OSES SCEC DEE HS os Dono s GoSeare 70, 73, 93 Be dea Sp sdeorte Absent se Se saennSas 14 Sa cie ncide Geen b SSS. He DEC nOCRin nO SOO pEEEaSuperseoS 52 Bean Point; rocks near... ---2.--!--\- <2 02--------=--- 15 | Bela clathrata Gabb\....-....-------------.ere- === noe 14,17 fidicula Gould . .......---.-----------++++-+-2--+-- 31,34 sanctz-monice Arnold .....--...-..----.---------- 34 Bibliography .....-.--..--------------++-++--------++ 142-146 Bittium asperum Gabb =..---- 24,27, 30, 31, 34, 117 californicum Dall and Bartsch ..........---------- 34 filosam Gould 33,40 254 INDEX. Page. Page. Bittium longissimum Cooper....-.------------------+- 14 | Cardium quadrigenarium Conrad-..... 22, 23, 24,30, 38, 95,121 quadrifilatam Carpenter 34 | os soopibecoUse ~looDs~ seme d coe: 17,19, 52, 79 rugatum Carpenter 34 | Carrizo Creek beds, equivalents of- - 10 williamsoni Arnold... 34 faumeobs <2 evens. Mocuse sae eee 5 PI) Blake, W. P., on Monterey shale -. 20 | Caryophyllia arnoldi Vaughan - 33 Boreotrophon cerritensis Arnold -. c 36 | californica Vaughan......-. be: 30 gracilis Perry ...-- 31,36 | PECTOCMsIs|Vau sha se eee ee eee een 33 multicostatus Eschse 36; 103: || \Gassisisp\==>--4 25-8 See. reese none ae eee 52 FD VC1E CUS WD) ie ee eee eae alle 27,37 | Catalina Miocene, equivalents of.................-...- 10 pedroanus Arnold: --.----.-....------42<-2---+-=== 36! Cephalopoda Soc... 2 ices cstec canoe ees aces Gos eee 17 triangulatus Carpenter ..-..-......-.---.--.------ 37 | Cerithidea californica Haldemann .................... 31,35 Bornis retifera Dall 2252. tere < renee ena nm 88 | ‘Cerithiopsis alternata Gabb_.-.2.---..-....--0----..-- 12,14 Borsonia bartschi Arnold - 36 | Cerostoma monoceros Sowerby 36 dalli Arnold ....-- 36 | Chama exogyra Conrad. ..- B 33 hooveri Arnold .........--.-- pellucida Sowerby-..-...--- . 30,33 Boulder Creek, Cal., rocks near | Chico formation, equivalents of.-.............----.--. 10 IBrachiopoda-ees=sostepeee tee eee oe | OCCUNTEN COLA sees se ese ce eae see eee 9 Brachysphingus liratus Gabb..-..-..-.-------.--------- 12,14 | Chicoreus leeanus Dall..........-.-2-0--2ssecceeee-2 36 GINUATUSIGAD Drceee ees aoe ace an ns cae cena neice 14 | Chione fluctifraga Sowerby........-........----------- 34 British Columbia, pectens of ---- 109,114 | gnidia Broderip and Sowerby ...........-.---.- 27, 34, 84 BMCCINUM IBD eee eee ees tee eee 1,116, 120, 123 | mMmathewsonlliGabbeseses. se ee a ene 19, 21, 55, 67,79 Billayhorni Gab besser misses eee tatel=tarare 14 neglecta: Sowerbyse. os. cee. teen eee eee cee 34 punctulata A, Adams 34, 95 simi lima So werbyicencenccac ee eccen aeons 81, 34 quoyi Gray .....-- 34 suceincta Valenciennes .... 19, 30, 34, 104 Billia'strigtasGaph)<— ~ 186 Callistata subdiaphana Carpenter ........-...-.------ 33,103 Wel ane) tel aes as Soanaas ces ase coon SEoeAnaasocs 69 Calyptrophorus sp... -..---------- §2 | HST C US MEME ee eee een eee er eee 16, Cancellaria cooperi Gabb.............--.-.------------- 35 26, 29, 33, 38, 49, 52, 55, 107, 112, 113-114, 115, 120, 234 CLAWTOLGIMMG AL ON eee aera cee ena enae 35 jordani Arnold.......-... 26, 29, 31, 34, 38, 49, 114-115, 232 inelaniane COOPEUssae soe emnnne ee see ae een rinse 14 janes! —-ee-ee nn 14, 38, 49, 51-52, 148 triton Geni Gab Passes -meretee = ce oesem ees see eee 35 latiauritus Conrad 6-27, 29-30, 33-34, velusta Gabbmrneasceceecsces con ccecss ocasmescuue. 84 38, 47, 49, 82, 91, 108, 115-116, 128, 129, 181, 137, 236 Up pe caadodsAcacocsodsnaces nod the siaeSspseoneser esos 84, 95 var. cerritensis.......-.-.-- 33-34, 38, 49, 129-130, 236 Gancersp oas-s22 ses ees cease 12 var. delosi...-...-. --- 33-34, 38, 49, 130, 236 Cardita subquadrata Carpenter. 33. | VETS LUGS PATHO] O tacsese rete =a eee 129 Sila ascaorncagecososasbecenesseanes6 85 | var. fucicolus Dall............. 33, 38, 49, 130, 131, 236 Carditamera subquadrata Carpenter.....-.------------ 33 | var. monotimeris Conrad .... 33-34, 38, 49, 82, 131, 236 RD wees Sect seen ete Sten ee emer panne 85 | IDR Guletls snccpaeSBoaesnscapacsesesan 27, 38, 49, 117-118, 234 Cardinmiubrewer GabbDesres tse-- aaeen eee saa 14,17, 61 nutteri.<:-2sse4-2s5-c-5- 19, 21, 23, 27,39, 49, 67-68, 105, 166 (Coro) Yoru EF 8) eno sooss Aa nmance-Seoeapbes= 12,14,55 | opuntia Dall.......-. 27-29, 39, 49, 91, 107, 116, 118, 123, 226 corbis Martyn. - - 30,33, 95,104 | parmeleei Dall 7, 29, 39, 49, 68, 100, 108, 119, 120-121, 226 elatum Sowerby .....2..2-222--- 83%,|\._) “proavus: ost Seen eee 11-12, 39, 52, 52-58, 148 linteum Conrad... E 14 BOSD CCUSIN ce es ere ate setae eee ee tats 19, 39, 49, 69, 160 meekianumiGabDb. -ca-oneaease Seer ce reins ccteem 24, 27,30 Vars Dy del .2 22 jeckjccattes 32 - 19, 39, 49, 69-70, 79, 83, 154 procerum Sowerby... 22-5205 oe cn ewnmerereneenn 33 | WASH DUMME ec ee nae ceeisetmneer eet 27, 39, 49, 119-120, 234 INDEX. 255 Page. Frage. Chlamys wattsi....... 27, 39, 49, 67-68, 95, 119, 120-121, 122, 166 Crepidula princeps Conrad. ..-- 19, 24, 27, 28, 30, 35, 79, 105, 117 VATS MOLa Meee eee eee ates 27,39, 49, 121-122, 164 | TUS OSAP NU OGAN Ls ceremonies aria eee ete ene ala 27, Sb; 95 Chlorostoma aureotinetum Forbes ............-...---- 35 | brunneum Phi ppitese=-cscsee cea eee eee 31,35 | funebrale A. Adams... 35 s var. subapertum Carpentér.................... BHU Crustdcese siete ce. cece ese eee as Meee 12,19, 24, 28 Ballina Rorbess ss. peewee ene ees 35 ryptochiton stelleri Middendorf a) montereyi Kiener 31,35 pulligo! Martyn, 22seere anon eee eee ene 35 Viridulum var. ligulatum Menke............-.---- 35 D) URSE ae css Roe acer So aecadun Sais that Sao madssesd 19, 24 Cholame Valley beds, equivalents of 10 Chorus|belcheri Hinds) =2-es-- see see eee 2 4, 35, 76, 111 Chrysodomus iiratus Martyn: ----..sc-5-- 2-2 2sse === 27,30 rectirostris Carpenter tabulatus Baird. 31,35 0, 31,35 Cidaris sp. . Sa SRecodkiees Clathurella Gani Gabb betas 31,35 Clementia subdiaphana Carpenter . 31 Clidiophora punctata Conrad..... 27,33 Clypeaster bowersi Merriam. 22 bre werianus: -..-s=es-ss— 17 gabbi Rémond.. 23 SP eehs pecs sue a7 Coceinodiscus sp- - Codakia.sp.2<=—. -<-2----- Columbella californiana Gactarn. chrysalloidea Carpenter....-. gausapata Gould..... var. carinata Hino minima Arnold oldroydi Arnold ... richthofeni Gabb ............-- solidula yar. praecursor Arnold . tuberosa Carpenter .. Colombia, pectens of........--...... Contra Costa Miocene, equivalents of oceurrence of Conus californicus Hinds horni Gabb rémondi Gabb -. BD eae tee eaeaeiseinieie Cooper, J. G., on Eocene fossils. 14 Cooperella subdiaphana Carpenter. 33 Coos conglomerate, equivalents of . 10 Coralliophila nux Reeve.........-. 35 Corbula aleformis Gabb......-.........-.----...-+---- 14 VATISLATI ATS MUU ree nate as relate tei 19 Latoya (CIS) 2) 3), a oe an oh ee Sea sar aise an Heeionc 14 Urb GACeVa IE (OF hy of shoo h ee oe Se e Seoce ods 30, 33 EAN KER I Sess pase Rea darn escsoohoaanananadaasosc. 14 LUN OTSA GAD ee meee onan ee eeieta nee eet 14 Sp ee ee re astm nny sccnesaeissee ae 17, 21, 27, 52, 65, 56 Cordiera gracillima Cooper.............-..------------ 15 microptygina Gabb 15 Correlation, post-Cretaceous, table showing..-.......-- 9-10 Crassatellites grandis Gabb...-.......--2.2-. 02-22-20 14 UTI OIGES 9 tal LON iae a eseiseida wenn t ee eae eee 12 TLV ESATA GOUT AC Gece een ae eeeias ace 14 Woacécdstessodtooscssrsss ota tious sAesvSes Sess sascos 52 Crassinellaibranneri Arnold so2- - 2c. ss= 205 =- = en ee ee 33 Crepidula aculeata Gmelin............-.-.-.-..--.---- 35 GAUNCASOWEID Y= ese eens wale ce e-em we meee 24,35 CGOrs8 Pap Brod ers pice se atenie ee aleleeeioe elses seein eae 35 navicelloides'Nuttall:. =. ==... .< 22. «cece ce soseue 27,30 OD YX I SOW ELD Veen = eee ian ois ieee eee ae 27,35 PRECLU Pts CONTEC seine talc ceten ea seers eata are 17 | Diastoma sp Cryptomya californica Conrad .........-....---- 0, 33, 6 Cucullza mathewsoni Gabb...............0..--------- Cumasbiplicata Gabbres--3-.---2 =~. se eisa ences Cumingia californica Conrad ... Cylichna alba Brown. costata Gabb horni Gabb .... petrosa Conrad ..... Cypriea bayerquei Gabb . mathewsoni Gabb .. spadicea Gray Cyrena californica Gabb -- Cythara branneri Arnold.... Cytherea yespertina Conrad. Dall, W. H., on classification of pectens.... --- 454 on San Pedro formation on Tertiary horizons. .... Deadman Island Pliocene, equivalents of - faUnarOfie Soe. 2 soe sees ance se laces 30-31 | Dentalium cooperi Gabb ..-. PAD: V7 D2 | indianorum Carpenter ...- 35 neohexagonum Sharp and Pilsbry . 28, 95 neohexagonum Sowerby -.-..-.-..--.---- 35 pseudohexagonum Dall .-..............- 35 semipolitum Broderip and Sowerby....-..--..---.- 35 stramineum Gabb substriatum Conrad Diller, J. S., on Oligocene of Washington -.-.-.-.-.--- 15 Diodus tenuis Gabbos.-- s.r ee ee ones ones se ee ee 15 Diplodontaiorbellf' Goulden Sos Sect Sede = 33 SELLICR LAR CONG ce oretates tae atelier ienis ee sein eae oe 21,33 Me naan sob ss Seco Coda sa FodBoOO DObs Jobe SORANS ASS EOS 57 Diploria bowers! Vaughan. 2... 052. js 2 - seen ces = = 22 Discohelix californicus Weaver.....-...........--..-.- 12 Dolichotoma carpenteriana Gabb...........--.--.. 27, 36,117 COOperLATNOdES = ee See sete cee cleclcceance ses ate 36 ULV ONIANH GAD Descance ss aese ce sce sees See oo 36,117 Os -cncbosve tes age coe co ASads eon esseS Sra Sossase pasooe 84 Dolium'petrosum Conrad... ..--..-.......----2-.-.----- 57-58 TID PENS SO WELD oo) on ss coe oa ae es Sees sete 22 WU sboatie ssectSoce osacdetbocacescuscoodsocaossSackece 17 Donax' californica: Conrad = 2.2.2. 2... de noses cence = 33 leeviga tasDeshayes-ea see cao. ches erae eet oe 33 TeVGUis| GalbDeeeecm scene esate see mee eects 14 Dosiniaconradi Gab Dasecees ae ose ee eiscs sec ees 19,79 ClOVALAG EDD Sine ope daniae cio cools oscar eae eee ee 14 RRB LANG AD Deen rea sree als eral ste ce erect eae 14 MALUEWSONIL GADD ate oc A eme= nce na meee cee ae 19, 79, 83 INONTANA CONTAC ss eee haa se tenetee seat teas 19,79 ponderosa Gray..... adbeTaeo2O506 19, 23, 27, 73, 79, 83, 104 BD ee Sn ac See nee Sas ee 22, 27, 65, 83-84 Drillia cancellata Carpenter---...-...-.:....-..2-.-.-- 35 EM PHU LORENG soe cle omen eee ee eee 35 inCisal Carpenter.© -cecarcvcccesccoecctee asta saeeee 27,30 256 Drillia inermis Hinds var. penicillata Carpenter......-..-1-.--.2:+-- 85 johnson ‘Arnold See se ee eee eee eee etre = 39 merriami AvimOlGe Seon. s5ee ea ena enone 31,35 montereyensis/Stearns=<5 oe cen ee ee ee a tees 35 pudica Hinds rp 85 (torosa; Carpenter: per seca eean eee ean 31, 35, 84, 117 ullreyana) Coopers sacs sateen see rere sects eee 15 RY 5¢ Sei cos aonSureasa sion ssc sonSscdbssscosesosaSsees 95 E. Echinarachnius excentricus Eschscholtz.... 28, 30,33, 99, 122 Sh sénao 4 scaosenseeec - 103,117 Echinoidea.......... 27, 28, 30, 33. | Empire beds, equivalents of - 10 Enspira alyeata Conrad ....-- 15 Eocene rocks, formations of - 9-15 fAUNMOL ease e se ae ae 11-12, 14-15 | occurrence of -- 5 9,10 pectensOnie -e-see-e se ~ 11,14, 37-41, 51-54, 148 Epiphragmorphora sp -..-- ise oa j Eponaiamathewso0nil Gabbee =. etn 2-2) = aeons HratoicolumbellaMen eyes yep ee ae ae see ee ete malate SD oe rene ole ace eaten ies eae ein eine peienot tie twos 5 Eulima falcata Carpenter. -.--..-:--.---..:------.----- aStA LAR SONVORD Yeates re ete Se mricans | Canpentensesnscsiics asech eae selenite Eupleura muriciformis Broderip ........-.----.-.----- muriciformis yar. curta Arnold F. Fairbanks, H. W., on Vaqueros sandstone......-.--.-- 18 Masciolariatio'Gabb.-....-2-2-0- cece. ecco a 145) leviuscula Gabb. 15 | SinuatalGabbies..erse<.c ose - =~ Fauna, fossil, lists of. ......- 12, 14-15, 1 INDEX. G. Gadinia reticulata Sowerby. ...-... -.-2----2-<-222-4-<- 35 Galeocerdo productus Agassiz...............-..-..- e 19 Galerus excentricus Gabb. . 12,15, 17,19, 79 inornatus Gabb ...-.- cs 27 Mam erisesrod Gxt piece. see te mee eee meee 17,19, 35 Gari alata Gabb 23 Gasteropoda.....-- 7-28, 30, 31, 34-37 Gastrocheena sp 22 Glottidia albida Hinds 22 = -- aoe ee oe eee eee eee 27 Glycymeris barbarensis Conrad .................-..--. 33 COL: GADD =v. saneegethw sees cnate sees Resear l4 PAtulus | Comrad/ccemercenaee ee Ceee eereee es 24, 64, 118 sagittata Gabbe cots < eee os Se oe ne eae eee eee 14 Septentrionalis Miaddendorf--.- 25-25 - +e. sees 33 veatchii Gabb var, major Stanton .-.............-- 14 SPivase eee eee eee 19, 21, 23, 52, 58, 73, 79, 83, 85, 118 Glyphis'densiclathrata ses. = sos. asada eens 91, 116, 123 Gyrodes:dowellixWihitesss-- = ss. seen cee eae 15 Ci eee topshastescoe saci] acausersbeeesor ec tote cans 73 i. Haliotishule ens Philippi sseeeeee = eee eee 3d Haminea virescens Sowerby ...-....-....-::-----s---- 39 Hamlin, Homer, on Vaqueros sandstone. ........-.... 18 HelcionidichotomaGabptce assent ee 12, 53 Helix (Hpiphragmophora)isp: a. 2.see-= 2.22. 2c 3d Heterotermajgabbi Stanton <-s-n.0 eee oe eee ee 12 SDELe Ge OUST LO Dimers arte sieege ee ea atch et er ane 12 trochoidea Gabb 12 Rss aS dso. eee hoes asdisewd so Ste Soeadoesacased IZ Hinnites Defrance ...-- -- 41,48, 50,94 corteziMDefrance a aii aeancscnccids see a cetetocee ere 50 crassa Conrad. . - 93, 94, 202 giganteus Gray oc Peay MLE 3, 38, 50, 93-94, 95, 109, 202 POUSONT CONTA ain saree see ates ele et ae 93 Hipponyx antiquatus Linné... 31, 34 Hyatt, A., on law of evolution 5 127 Hypogella diegoensis Gabb................-.-..-.----- 14 16 Isapis tenestrata Carpenter... 2-5-2 - s+ - ee -ne ccm ence 35 Ischnochiton regularis Carpenter ...........-..---.--. 39 | Ivara turricula (Carpenter) Dall and Bartseh......... 35 J. CONG UE CONTAC am amab ia ite etea cae ice eer eects 95-96 Gentata): COOPER = s...eiae i scaiialle oo seen ae ee ee 100 Gentatd Gab oases meena see oeeee ances see cae 100 dentatm@ Sowerby; - 2225.2 oem -aetaneseesee ce see 135-136 a (fotarene is bbe LVR er aaas St oa soso ne epeseseem steed 128 K. Kellia laperousii Deshayes ............. - 30,33 suborbicularis Montague ..-. 5 33 Kennerlia bicarinata Carpenter - 33, 103 filosa Carpenter.............- 33 grandis Dallis...22 ase eenensac nase eeacieene ee 103 L. Lacuna compacta Carpenter 35 porrecta Carpenter cents mqesers neem eee aee er 39 localities where found, lists of... 11,13, 16, 20-2 2 Favia merriami Vaughan..............-..-- 22 Ficopsis angulatus Weaver . iP) cooper. Gabbi-2 == =. =. 15 horni Gabb ...- 15 rémondi Gabb -.. 15 Fissurella voleano Reeve 35 Fissuridea aspera Eschscholtz .........--..---.-------. 35 INES WALIS SOW CLO Y eee wea csee cine alee len ae inaaleiees 35 | murmns (Carpenter) Dalle seen ee ee ee 35,95 Cae Eaeiseosdesennis costa ose ktins COE COS EEE OA Iocab 19 Flabellum californicum Vaughan..................... 14 TEMONCIAMUIMNIG AD Disease selene sete anaeieee ) Neritaimangulata Gabbe econ asec toe aoe ee 15 Mitramorpha filosa Carpenter .....-...--.---.------+-- 36. || NeveritaglobosaiGabbiee,.o8s.e weer ae nee 15 intermediavArn Old je aaeecte cece seen eee ae 36 | recluziana Petit 19, Modiolus fornicatus Carpenter .........-.-..---------- 34 8, 31, 36, 79, 91, 95, 104, 116, 121, 128 MEITIAM IT Wie VCDs nae cen se eee eee aa ae see ee 12 saxea' Conrad’ (25. So~ see etecets cameo este ee 17 OTM AUS GADD pee aaa ae ones - 12,14, 51 Becta Gabb ino! scasko< stews ecwenceetns ace een sees 15 rectus! Gonrad = +522 cee ab osseee eee 28, 30, 34, 95 Raa anunacgaacoD aa to sane ease acac sees s Sede kana 24, 120 SP ecco apace re iain eco roe mainte eters cinta tara sretsioiniatee 17;28;69 4" Nodipecten\Dall?:... .222-.-. 25 <5 s2see 5-52 csseec eens 41,49 Moerella salmonea Carpenter .....-..-...----------.-. 27,34 MOdosusWinne-2. stan s sess Be eae ee Ser ae 49,129 Molopophorus striata Gabb...............--------.---- 14 | subnodosus Sowerby ... 33-34, 39, 49, 107, 128-129, 248, 250 Monia macroschisma Deshayes.........--------------- 34 | VveatehiiGabb.-.. 2.0522 -see onisine o oe 39,50, 189, 240 vancouverensis Whiteaves..-. 39, 50,101, 133,139, 140, 248 Pseudocardium gabbi Rémond ......-.-...-....------- 24 Pteria limulai Conrado. 2 oe soos a vee wctecins seseee 52 Pterobytisfoliatus Martyn’: <. 2. -se-. nesses nit oe 36 mutta Conrady ees cecce one oecis sale cenesnaascee 36 Pteronotusfestivus Minds 2-2-2... 35. ce nsec. see os sens 36 Puget group, equivalents:of - 2-0... 2c 5 22s en eeee men 10 Puncturella cucullata Gould .............-.-.-.--.---- 31, 36 ALC ATA GOUIG weeny cee ee ree terial acento ere 31, 36 Purisima Creek, Cal., rocks near --..-----...-..------- 25 Purisima formation, character of..............---..--- 25-26 CULV aIeTIS Olle seamen are ce eine eee eee 10 OREM Oe noc ore mooadeqnogcosasorsecosococteces=00 26-28 (OC CUITEN CEO Leese teseelectenio = oie lninie eisteetetet erate 9, 25-26 pectens of 26-27, 37-40 Purpura canaliculata Duclos..........---.--..--..---- 24, 30 crispata| ChemnitZe-- 22s -se--= eee eee 28, 36,117 saxicola Valenciennes.........-..-......--..-.. 24, 30, 36 262 INDEX. Page. Page. Pyramidella conica var. variegata Carpenter -. Septifer bituncatusi Conrad! s.-=--sceasose eee eeeee sees 34 PY TULOT SD ree oer cies oa nl eaciaee ee eee ee enemies eae GichotomisiGabbessssscessaa= ae see ae eee 14 Serpulalspisss ses ssi. ote cee eee eee eee eee eee 12 Ranella californica Hinds .....-.----.---.-<.-2-:--. Serpulorbis squericerua@arentart naapeccnesoansostes MehBts Fe nn oe tee MRT 2 ST. he Siderastrea californica Vaughan ..................---- 22 Range of California pectens. Sigaretus debilis Gould..-.----.------- 5... --- eens 28, 36 Seale Urine oars scopulosus Conrad. ........-22/.2-220052.2secteeees 17,19 Recent time, pectens of..... 37-40, 48-44, 94, 103, 111-114, 116, Wes oc Sp ancaeRosannsrnsecrosgsS sr S2sc arbi therea ane 65566 126, 128, 130, 202, 220-222, 226-236, 240, 244, 246-250 Siliqualucidel@onnad Sea... ae eee eee eee 27,34 Rictaxis punctoccelata Carpenter -. 34 patula Dixon ...-----------..-----------.. 27, 28, 30, 103 Rimella canalifera Gabb .......-- 15 yarmmuttalll Gonradi = 1 Sa eeeeeereee 34 simplex Gabb........-.. 15 SP --- 22-222 e eee sete ee ere ee eee erence eter eee ee 21 Rissoa acutelirata Carpenter ....... 36) siphonaliatkellettil Worbess..-- seme: eenee e- ateeie 36 Rock Creek Eocene, equivalents of. 10 | lineata Stanton ............-..---2.-2--2- eee eee 12 Rostellaria indurata Conrad...- 28,105 | Siphonodentalium pusillum Gabb....-.....-..-....... 15 Rupellaria lamellifera Conrad..............--.----+--- 34 || Solariella’cidaris| Ay Adams: 2-22-25 -- sees -ssseee as 31 sd peramspilisiCanpenten.2-e)- esse -eeer eae sone eee 28,31 S. Solarium amoenum Conrad................-.-.-.<----- Salinas Valley, Cal., formations in .................--- 10, 24 BP sab a6 bie wets See doce hoes Pee ocec ame eee een sete eats San Diego formation, equivalents of ...........-.-.--- 10. Solemya ventricosa Conrad yo SERUIODI ON, Ranh SA Gr soso Sanco can soscnse ana esooeS 28 SPesessPase on. Sees se ouescan ee comet een eee San Joaquin Valley, formations in.................-.. LO eSolenicuntus) Conrad. asses ese eee ee ae eee San Juan de Fuca Strait, rocks near ..........-..-:.-- 15 diepoensis|Gabbic.>- =e eee ee eee eee San Lorenzo formation, character of.................- 16 parallelus Gabb. .. CLoqbey ZNO OH sac ooged cas con eae Sad asoTeSSSOs GORE 10 sicarius Goull .. HERVE) Oh Sane nosebanes sabe okn Sa ce cooSsecHansoon Scene 16-17 stantoni Weaver. . OCCUTIEN Ge Olas ee ee erinener am teow le come cite vaciaies 9,16 | Sp teseeesns ootveasOees DE GLENS Olan eeeeen een teee el cee ciate teiain enea aiass 16,3740 | Sooke beds, equivalents of San Pablo Bay, Cal., rocks near..............-..-----. 22 Spiroerypta pileum Gabb-.- San Pablo formation, character of .........-.--------- 22. Spiroglyphus lituella Moreh. Crop NETO? oa scent kane sostes Soeooneececonsasse 10 Spirotropsis Smithi Arnold .. HUES) oo ceS egos ro neeree eos coee sess ooree cs stecice 23-24 | Spisula catilliformis Conrad..........-........-- 27- 28, 34, 67 OC CURT N CE10 te mmeetsts setae steiner sein ieleeinia tans eeia 9, 22 ToL CALAN G OU G serrctrstasrs tational tate ee ee ers 27,30, 34 TELE) ioe = - Serie SOn SSSR EOSSSDOSSEE conacer on 23, 37-40 SD iv wc we cesta sie os see ges e ace eeeetnacuc sesame coseeere 66 SaniPedro#C@al"srocks from sc. ccscs-se- ee ee seen 32.5 |e 'Spond yIs soe = aac ee aoe nee ee eee ene ee 46 San Pedro formation, character of ..........-.....---- 32 IBgtratlensis' Conrad) a2s2--s-t eee ean eoeeeee 7 (SoU Oe pea ear oeaoecpser oacopseearoacsascs 10 Mstrellantus! COnTads.--cses setae acess ae eae eee 71 EAD ECL GB cr agadcoboscoen eae SaLase pare eR I beENeOnas Sc 37 Stalagmium concentricum Gabb...........-..-......- 4 occurrence of | Stanton, T. W., on Tejon formation fossils............. 14 pectens of | Stephanocoenia fairbanksi Vaughan........-...-..... 22 Sanguinolaria nuttalli Conrad... 34 | var. columnaris Vaughan 22 Santa Cruz, quadrangle, rock in. ! 16 Stratigraphy, value of Pecten genus in fetecmintiaes 2 Ht Santa Margarita formation, equivalents of - 10 | Strepsidura pachecoensis Stanton ....-........--.....- 12 fauna of - 24) Strombus granulatus Sowerby...-...........---.--.--- 22 Santa Rosalia, Mex., fossils from --- 84-85 BD)ofe a Jone sacs oO doe ocletane Sie tase oa rs a ae em ar 22, 85 Saxidomas gibbosus Gabb -. 19, 24,2 30, 64,83 Strongylocentrotus franciscanus Agassiz .............- 3 24,30, 34, 73 purpuratus Stimpson ......................-.-- 28, 33, 120 21 Styliferina tenuisculpta Carpenter .................... 36 Scala bellastriata Carpenter . 36 | Surcula claytonensisGabb............----------------. 15 crebricostata Carpenter. 36 (CREHALOSDira) COO DET A aan san pean =a ee eee ae telat 5 hem philhgD alll Basses eats eee see elements 36 inconstans' Coopers. cee scsn soe eases ses Sane cess 15 hindsii Carpenter. ...... : 36 moniliferas Cooperieees seneas oak ees ee eee 15 indianorum Carpenter. ---.......---.-..---.....-.- 31, 36 preattenuata Gabb...........--.--..---- 15 stearnsii Dall... 28, 100 TATicOstataiGab by eee ssee een eee eee 15 LCL CLA) CE IO MLC rates eee rereistoe atten eaters aint 28,36 | ginuatalGabDiiesesseeeneeeeeeeee eee 15 CGH AE noob SSG Eco Sannans: brsdsoncboopscR copsaoa 17,117 Z Scalaria mathewsoni Gabb ...........--...-.---------- 15 T. Schizaster lecontei Merriam..-.--........---.5...----- 12 | Tagelus californianus Conrad....................-.-.- 34 Sconsia tuberculatus Gabb ....-..-.......+22--+---0e- 15 | Tamiosoma gregaria Conrad .-..-....-..-.-- 23, 24, 64, 76, 111 Scutella fairbanksi Merriam .......-.--...-..-.--- 19}/70, 122) ||/"Rapes'conradiana Gabb). 2... ..2cs--eseeeniaseeaci=as 14 PMI AG ann eo Reo Ako soduostsoseescssoS 23 Cretacea Gabb\inss <2) Sees a cinesiaceseenics cesses 14 interlineata:s iim pone seem oes eae cicreeeam aan ate 27, 30 lacinedta\Carpenten a... == = see one ear eee 34 Wongancoenstiagobdsdees Suse ehopSe spas oaecr asec 92-93, 103 quadrata Gabb Seilajassimilata (©. Bo-A'dams)- 2-2 - ccc ccc-ce-cs=- cee 36 Stalleyi'\ Gab Dose seees eels ee eet SemeleidecisaiConrad:ces-—-4-< oo eae cn eeineeree cris 34 stamineaConradis-.225-sce eon eee aeeree "of, 28, 30 PUNCH Ta SOW CLR Vara etetetetats tata tele ate et eeetate telat eit = 34, 85 tenerrima Carpentera- se. fone asso eee eee 27,34 var. montereyi Arnold...............---------- 34 EYUNCRTA GADD sesemallata aimee sitecelaincstctecten eteeiniatecterste 19, 83 Matescoccodtes acacodeecodcrossocacnccdbacadcas noeeae 61 SP eccvccvccccecercees eeccssccccsevenncenanses Loyal, 03,07 INDEX. 2638 Page. Marans: strong ieAmno] dine sececciite sleissels ine fate ee moe 31, 36 Tejon formation, character of 13 equivalents of .-..-..-..- 10 fauna of ....-- 14-15 occurrence of. 9,13 pectens of st Tellina equalis Gabb nce Sr oss ao neeecASasbassannaduens 12 arctata Conrad -.. 17, 66 bodegensis Hinds . 19, 34 g californica Gabb . 14S hero Dp HOnCenTLeNSISVATTO lyase eer rena ae Ser ea ae as 36 congesta Conrad... -- 27,57 PTACUIShPernye ess doce jeans Heiss ae a eee eae sae 31, 36 hoffmanniana Gabb . 12 multicostatus Eschscholtz hornii Gabb ....... - 12,14 orpheus var. precursor Arnold idee Dall . 34, 84, 104 pacificus Dall..... longa (ei. * 14 pedroanus Arnold martinezensis Weav ere 12 ponderosum Gabb oregonensis Conrad ... 17 Stuarti Smith .-.......- rémondi Gabb.....- 14 tewMMiscul pra Carpenters. <-. secs. ancieo eee eee eee 31 rubescens Hanley . 34 inianeulatus;Carpentenes.o4- cee sce eee ee 37 undulifera Gabb. we Tunnel Point beds, equivalents of..-.............-...- 10 SDN ae eee teens Turbinella crassitesta Gabb ...- 12 Terebra californica Gabb .- simplex Carpenter -... 31,36 wattsiana Cooper. . 15 iB eséoaeeccse cease sege S4 Terebratalia smithi Arnold 30 hemphilli Dall .......... 107 Terebratella transversa Sowerby - 120 SDea centro ee catereoee ‘Trebratula nitens Conrad 17 ROsseqodepcacedsc osanetecaeedoe 07,58 | Terebratulina tejonensis Stanton . . - 12,58 METEC O'S Poe Seecien seneioue tam eetaeiee 12, 55, 57 Thalotia caffea Gabb .... 2131736, Theliostyla ciksvayegoilens Gabb. Es 15 Thracia karquinesensis Weaver... 12 GullerieD allie e eee eee : S 52 trapezoides Conrad. Z 17, ‘31, 34, 103 SMhyasgira bisecta| Conrad =. .cses. = ee tose eececeineee 31 gouldii Philippi - 31,34 Pen coostceuersocessongoese 17 Tivela crassatelloides Conrad . 34 ineziana Conrad......... 9, 83 Tornatina cerealis Gould 36 eulecitella Gould...- 28, 36 eximia Baird - 3L harpa Dall...... 36 Trachycardium sp- - 19,79 Trachytriton diegoensis Gabb- 15 fusiforme Gabb. 15 ie) OOM S18 1 Ge DO Peeterersletetela (ase ieeinnietaets cise) een 15 Tresus nuttalli Conrad. 27, 30, 34, 73, 103 RM ccasseasactuereass cocpacces ony assadppeaecoan sas 24, 64 Triforis adyersa Montague .- 5 36 Tritonium californicum Gabb. - 12,15, 53 dieroensis Gabber. 2ns ses acco se - vaeeesee eae ose 15 eocenicum Weayer - 12 fusiforme Gabb - 15 gibbosus Broderip 36 horni Gabb ....-.. 15 impressum Weaver .. 12 paucivaricatum Gabb - 15 Ul Chime WCAC Weta teeta ain ations = ine aes aie 12 erases (CGH) a) oo ome sn cme mano oCoSEeicomeTS .C Caan 15 whitneyi Gabb ... sa5 15 seat cesténcoccaspossesoos 19, 24, 28, 52, 55, 73, 83, 93, 104 Tritonofusus'cretacea Gabb:.-.-...-..-.5-5-.--------c- 15 ‘Drivinicalitornica\Gray-. sees: --cdes sesso ene noses 36 sp- Turbo sp Turbonilla adleri Dall and Bartsch. arnoldi Dall and Bartsch... aurantia Carpenter -. erebrifilata Carpenter gibbosa Carpenter - - laminata Carpenter...... latifundia Dall and Bartsch lowei Dall and Bartsch. . muricata Gould......-....- pentalopha Dall and Bartsch. similimis C. B. Adams - stearnsii Dall and Bartsch. subeuspidata Carpenter . tenuicula Gould torquata Gould torquata var. stylina Carpenter. tridentata Carpenter Turner, H. W., on San Pablo formation fossi Turris sp Turritella conica Weaver cooperi Carpenter hoffmanni Gabb...- infragranulata Gabb. jewetti Carpenter. -- martinezensis Gabb. 31, 37, 95, 100, 104, 117 . 18,19, 22, 69-70, 73, 79, 93-94 ocovanei Conrad's “6 ri sc5 ace onc ocn ese see 18, 19, 83, 84 pachecoensis Stanton..........---- Seposienseoucoste 12 uyasana Conrad : variata Conrad . SMonocctiscesesticotesSbccss ase oseo Ten cHSSRESSso 24, 30,58 U. UniopenwltimnsiGabbss 7. .-.c0 see ee pe eee ee 14 Urolophus*halleri(Cooper-<-- =... -s.2---24-+ see e-e=== 37 WrOSsyCacandataGa Db ween risa eesa ss eee eae Setanta 12 8) SUED \YVGIA Slee ee han Sear Gas eSce aco seasheescosoe 12 Vv. Vaqueros formation, character of. ...-.....-.-.---.-... 18 equivalents of 10 famnaioil<---\ 2. 18-19 occurrence Ofit=. Ss cpantaccase ewer esac eee eee 9,18 PEGHENS Ole seem eee eee eae ee ere ee Vaqueros Valley, Cal., rocks in Venericardia barbarensis Stearns. ...............--. --. 31,24 204 INDEX. Page. Page Venericardia planicosta Lamarck ..........---------- 14,52 | Volvarina varia Sowerby ........-...---.-2------------ 37 planicosta var. hornii Gabb.......--..------.--- 12,14,51 | Volvula cylindrica Carpenter ..-..---...-.--....--.-.. 37 VEltGoOsa GOULG .ciseeeptsecteiae eee 30-31, 34, 100, 117-118 Eg a weecc est undere an sbote Mon sods decoseods stasssce 57, 66 Wie Venusiequilaterslis'Gabb oo. oo -pene = eee oe 14 | Washington, formations in - Auctiiraga SOW SLD vessels eee eae eee aaa 34 fossils {rOM): ssc ccc coescc cee e gnidia Broderip and Sowerby .-.--..-------------- 34 | Whitney, J. D., on Martinez formation Henticularis! GADD ete. ea see eee eee Sooceiaraess 17 on Tejon formation. .......-.------ = 13 neglecta Sowerby Wildeat formation, equivalents of........-.--------..- 10 pertenuis| Ga Dye eee sees er eeee te ae simillima Sowerby -. 31,34 D>. SUCCINCLANV BLED CLONES se a-eieee es = eer eee 34 e - ape ‘pratt eiinitet 34 Xenophora zitteli Weaver ...---- See Ameen fe aos 2 bescon 12 Sposa saeco 83-84 = Vermicularia sp -. 37 we Verticordia novemcostata Adams and Reeve 34 | Yoldia cooperi Gabb - 19,27, 34, 83 Vitrinella williamsoni Dall.. 37 impressa Conrad .........----+-+-+++++2+222s2-2+22+ 17, 55 Vola dentatus Sowerby ..--- 135 Scissunaita(D all eS ee ee eee ee 27, 34, 103 floridus Hinds. 2 127 SD eeeeee eet: _ 95, 100 Z. Volutilithes sp... =i 57 | Zirpheea gabbi Tryon eee -- 27,34 Wolutatsp mecsasesereeceeest BED Pe eee a ee ee 28, 86 CoS Pp aera a OoCo ae RO aricos ere saa sedans ssascacaas 24 CLASSIFICATION OF THE PUBLICATIONS OF THE UNITED STATES GEOLOGICAL SURVEY. {Professional Paper No. 47.] The serial publications of the United States Geological Survey consists of (1) Annual Reports, (2) Monographs, (3) Professional Papers, (4) Bulletins, (5) Mineral Resources, (6) Water-Supply and Irrigation Papers, (7) Topographic Atlas of the United States—folios and separate sheets thereof, (5) Geologic Atlas of the United States—folios thereof. The classes numbered 2, 7, and 8 are sold at cost of publication; the others are distributed free. A circular giving complete lists may be had on application. Most of the above publications may be obtained or consulted in the following ways: 1. A limited numberare delivered to the Director of the Survey, from whom they may be obtained, free of charge (except classes 2, 7, and 8), on application. 2. A certain number are delivered to Senators and Representatives in Congress, for distribution. 3. Other copies are deposited with the Superintendent of Documents, Washington, D. C., from whom they may be had at practically cost. 4. Copies of all Government publications are furnished to the principal public libraries in the large cities throughout the United States, where they may be consulted by those interested. The Professional Papers, Bulletins, and Water-Supply Papers treat of a variety of subjects, and the total number issued is large. They have therefore been classified into the following series: A, Eco- nomie geology; B, Descriptive geology; ©, Systematic geology and. paleontology; D, Petrography and mineralogy; E, Chemistry and physics; F, Geography; G, Miscellaneous; H, Forestry; I, Irrigation; J, Water storage; K, Pumping water; L, Quality of water; M, General hydrographic investigations; N, Water power; 0, Underground waters; P, Hydrographic progress reports. This paper is the seyenty-sixth in Series C, the complete list of which follows. (PP=Professional Paper; B=Bulletin. ) SERIES C, SYSTEMATIC GEOLOGY AND PALEONTOLOGY. B_ 3. Fossil faunas of Upper Devonian, along the meridian 76° 30’, from Tompkins County, New York, to Bradford County, Pennsylvania, by H. S$. Williams. 1884. 36 pp. (Out of stock.) B 4. Mesozoic fossils, by C. A. White. 1884. 36 pp.,9 pls. (Out of stock.) B 10. Cambrian faunas of North America; preliminary studies, by C. D. Walcott. 1884. 74 pp., 10 pls. (Out of stock.) B 11. Quaternary and recent Mollusca of the Great Basin, with descriptions of new forms, by R. Ellsworth Call. Intro- duced by a sketch of the Quaternary lakes of the Great Basin, by G. K. Gilbert. 1884. 66 pp., 6 pls. B 15. Mesozoic and Cenozoic paleontology of California, by C. A. White. 1885. 33 pp. (Out of stock.) B 16. Higher Devonian faunas of Ontario County, New York, by J. M. Clarke. 1885. 86 pp., 3 pls. B 18. Marine Eocene, fresh-water Miocene, and other fossil Mollusca of western North America, by C. A, White. 1885. 26 pp., 3 pls. B 19. Notes on the stratigraphy of California, by G. F. Becker. 1885. 28 pp. (Out of stock.) B 22. New Cretaceous fossils from California, by C. A. White. 1885. 25 pp., 5 pls. (Out of stock.) B 24. List of marine Mollusca, comprising the Quaternary fossils and Recent forms from American localities between Cape Hatteras and Cape Roque, including the Bermudas, by W. H. Dall. 1885. 336 pp. B 29. Fresh-water invertebrates of the North American Jurassic, by C. A. White. 41 pp., 4 pls. B 30. Second contribution to the studies on the Cambrian faunas of North America, by C. D. Walcott. 1886. 369 pp., 33 pls. (Out of stock.) B 31. Systematic review of our present knowledge of fossil insects, including myriapods and arachnids, by 8. H. Scudder. 1886. 128 pp. B 34, Relation of the Laramie molluscan fauna to that of the succeeding fresh-water Eocene and other groups, by C. A. White. 1886. 54 pp., 5 pls. B 37. Types of the Laramie flora, by L. F. Ward. 1887. 354 pp., 57 pls. B 41. Fossil faunas of the Upper Deyonian—the Genesee section, New York, by H. S. Williams. 1887. 121 pp.,4 pls. (Out of stock.) 1 5 to dah 63. Benn dnd 6 ww SERIES LIST. 3. Tertiary and Cretaceous strata of the Tuscaloosa, Tombigbee, and Alabama rivers, by E. A. Smith and L. CG. Johnson. 1887. 189 pp., 21 pls. . Invertebrate fossils from the Pacifie coast, by C. A. White. 1889. 102 pp., 14 pls. (Out of stock.) . Fossil wood and lignite of the Potomac formation, by F. H. Knowlton. 1889. 72 pp., 7 pls. Bibliography of Paleozoic Crustacea from 1698 to 1889, including a list of North American species, and a systematic arrangement of genera, by A. W. Vogdes. 1890. 177 pp. . Classed and annotated bibliography of fossil insects, by S. H. Seudder. 1890. 101 pp. . Index to known fossil insects of the world, including myriapods and arachnids, by S. H. Scudder. 1891. 744 pp. . The Texan Permian and its Mesozoic types of fossils, by C. A. White. 1891. 51 pp., 4 pls. . Correlation papers—Deyonian and Carboniferous, by H.S. Williams. 1891. 279 pp. (Out of stock.) . Correlation papers—Cambrian, by C. D. Walcott. 1891. 447 pp., 3 pls. (Out of stock.) 2. Correlation papers—Cretaceous, by C. A. White. 1891. 273 pp., 3 pls. (Out of stock.) . Correlation papers—Eocene, by W. B. Clark. 1891. 173 pp., 2 pls. . Correlation papers—Neocene, by W. H. Dall and G. D. Harris. 1892. 349 pp., 3 pls. (Out of stock.) Correlation papers—The Newark system, by I.C. Russell. 1892. 344 pp., 13 pls. (Out of stock.) 5. Correlation papers—Archean and Algonkian, by C. R. Van Hise. 1892. 549 pp.,12 pls. (Out of stock.) . Synopsis of American fossil Brachiopoda, including bibliography and synonymy, by Charles Schuchert. 1897. 464 pp. . Cretaceous foraminifera of New Jersey, by R. M. Bagg, jr. 1898. 89 pp., 6 pls. . Some insects of special interest from Florissant, Colo., and other points in the Tertiaries of Colorado and Utah, by S. H. Scudder. 1892. 35 pp.,3pls. (Out of stock.) . Mesozoic Echinodermata of the United States, by W. B. Clark, 1893. 207 pp., 50 pls. Flora of the outlying Carboniferous basins of southwestern Missouri, by David White. 1893. 139 pp., 5 pls. . Insect fauna of the Rhode Island coal field, by S. H. Scudder. 1893. 27 pp., 2 pls. . Catalogue and bibliography of North American Mesozoic Invertebrata, by C. B. Boyle. 1893. 315 pp. . The Laramie and the overlying Livingston formation in Montana, by W. H. Weed, with report on flora, by F. H. Knowlton. 1893, 68 pp., 6 pls. . Colorado formation and its invertebrate fauna, by T. W. Stanton. 1893. 288 pp.,45 pls. (Out of stock.) . Paleozoic section in the vicinity of Three Forks, Mont., by A.C. Peale. 1893. 56 pp., 6 pls. . Devonian system of eastern Pennsylvania and New York, by C. S. Prosser. 1895. 81 pp.,2 pls. (Out of stock.) . Bibliography of North American paleontology, by C. R. Keyes. 1894. 251 pp. . Revision of North American fossil cockroaches, by S. H. Scudder. 1895. 176 pp., 12 pls. . Bear River formation aud its characteristic fauna, by C. A. White. 1895. 108 pp., 11 pls. . Contributions to the Cretaceous paleontology of the Pacific coast: The fauna of the Knoxville beds, by T. W. Stanton. 1895. 132 pp., 20 pls. . Cambrian rocks of Pennsylvania, by C. D. Walcott. 1896. 43 pp., 15 pls. . Eocene deposits of the middle Atlantie slope in Delaware, Maryland, and Virginia, by W. B. Clark. 1896. 167 pp., 40 pls. . Brief contribution to the geology and paleontology of northwestern Louisiana, by T. W. Vaughan. 1896. 65 pp.4 pls. . Potomac formation in Virginia, by W. M. Fontaine. 1896. 149 pp., 2 pls. . Lower Cretaceous grypheas of the Texas region, by R. T. Hilland T. W. Vaughan. 1898. 139 pp., 35 pls. . Catalogue of Cretaceous and Tertiary plants of North America, by F. H. Knowlton. 1898. 247 pp. . Bibliographic index of North American Carboniferous invertebrates, by Stuart Weller. 1898. 653 pp. . Flora of the Montana formation, by F. H. Knowlton. 1900. 118 pp., 19 pls. - . Synopsis of American fossil Bryozoa, including bibliography and synonymy, by J. M. Nickles and R. §. Bassler. 1900. 663 pp. . Bibliography and catalogue of fossil Vertebrata of North America, by O. P. Hay. 1902. 868 pp. . North American geologic formation names: Bibliography, synonymy, and distribution, by F.B. Weeks. 1902. 448 pp. . Structural details in the Green Mountain region and in eastern New York (second paper), by T. Nelson Dale. 1902. 22 pp., 4 pls. . Fossil flora of the John Day basin, Oregon, by F. H. Knowlton. 1902. 153 pp., 17 pls. . The Mollusca of the Buda limestone, by G. B. Shattuck, with an appendix on the corals of the Buda limestone, by T. W. Vaughan. 1908. 94 pp., 27 pls. . A study of the fauna of the Hamilton formation of the Cayuga Lake section in central New York, by H. F. Cleland, 1903. 112 pp., 5 pls. . The correlation of geological faunas; a contribution to Devonian paleontology, by H.S. Williams. 1903. 147 pp., 1 pl. . Stratigraphy and paleontology of the Upper Carboniferous rocks of the Kansas section, by G.I. Adams, G. H. Girty, and David White. 1903. 123 pp., 4 pls. . Carboniferous formations and faunas of Colorado, by G. H. Girty. 1903. 546 pp., 10 pls. . Contributions to the geology of Washington, by G. O. Smith and Bailey Willis. 1903. 101 pp., 20 pls. . The geology and ore deposits of the Bisbee quadrangle, Arizona, by F.L.Ransome. 1904. 168 pp., 29 pls. . Zine and lead deposits of northern Arkansas, by G. I. Adams, assisted by A. H. Purdue and E. F, Burchard, with a section on the determination and correlation of formations, by E. O. Ulrich. 1904. 118 pp., 27 pls. . Preliminary report on the geology of the Arbuckle and Wichita mountains in Indian Territory and Oklahoma, by J. A. Taff, with an appendix on the reported ore deposits in the Wichita Mountains, by H.F. Bain. 1904. 97 pp., 8 pls. . Preliminary report on the geology and underground water resources of the central Great Plains, by N. H. Darton. 1905. 433 pp., 72 pls. SERIES LIST. Ti B 244. Contributions to Devonian paleontology, 1903, by H. S. Williams and EB, M. Kindle. 1905. 137 pp., 4 pls. PP35. The geology of the Perry basin in southeastern Maine, by G. O. Smith and David White. 1905. 107 pp., 6 pls. PP36. The lead, zine, and fluorspar deposits of western Kentucky, by E. O. Ulrichand W.S.T. Smith. 1905. 218 pp., 15 pls. B 257. Geology and paleontology of the Judith River beds, by T. W. Stanton and J. B. Hatcher, with a chapter on the fossil plants, by F. H. Knowlton. 1905. 174 pp., 19 pls. B 266. Paleontology of the Malone Jurassic formation of Texas, by F. W. Cragin, with stratigraphic notes on Malone Mountain and the surrounding region near Sierra Blanca, Texas, by T. W. Stanton. 1905. 172 pp., 29 pls. PP 40. The Triassic cephalopod genera of America, by Alpheus Hyatt and J. P. Smith. 1905. 394 pp., 89 pls. B 268. Miocene foraminifera from the Monterey shale of California, with a few species from the Tejon formation, by R. M. Bagg, jr. 1905. 78 pp., 11 pls. PP 47. The Tertiary and Quaternary Pectens of California, by Ralph Arnold, 1906. 264 pp., 53 pls. Correspondence should be addressed to Tue Drrecror, Unirep States GEOLOGICAL SuRVEY, WasuHinaton, D. C. Marcu, 1906. - > i ao - a F - ; - 5 = ir * F Ss en) - “ ja 7 (ca ai « aT i 5 — — Oarded te i ° - . a 4 7 r cs ri) 7 i ti - > * ote ene ? _ MOS reservation ' | i aa ¥ Services | ay re Oe ‘ - i) “Seat igs ea a Are "9 a " ” AS ' + i s a ; . o H ij t | Il i Ih ONIAN INSTITUTION LIBRARIES | | l II | 3 9088 00048 | | | Va wt feral rs nil eee Yoon ee “ Balan nc: : a ier NAAR NS al ary A vy AAR Am an A AAAAAAARABAAARS aa Aa, im Aaa at yt Da NEN Ve \p Seaaeeia pannnne’ NAA papal BiG Fa ih We Val pA BAGO mannnnrre neo Ann AA NN nannnnnnnARnanran a panann Le en DA MENS a Wes amano We