THE EISENHOWER LIBRARY 3 1151 02695 9639 JlJtwHCTiMjCwi! .r •»l \ iiaiC^r THE M0LLU-3GA OV THE 30WDEF BEDS OP JAIvIAIOA. ,-000 — A Dissertation >Si;;omitted to the Board of University Stiidies of the Johns Hopkins Unirersity in couformity with the requirements for the degree of Doctor -■ " Philosophy by 7Z.1T)EII PHILIIP3 WOODKING Baltimore ray, 1916 \- ' 1 Preface .1 Ackno'^.'ledgeraeiit;: E Introinction 5 .4nalvs is of t he 7auiig 6 3iol":p'icsl ilnalr/eis t/ ' o Scoloeical Analj-sls , 13 Geological Analj'cis 20 S;;steriiatio DiccuGSion 42 Order PrionocTesmacea d-2 Family- lluculidae. . . .- 42 ?aiiiil^- le di dae 49 7amil3? limopsidae 76 P'amil;- Arcidae ni Pamily Pinnidae 1"! Family Helinidce 175 Pamilj; Pteriidae 176 ?amili^ Oatreidae 178 .?arailv' Pectinid -e 194 Family Spond^^li d.ae £?' t Familj; limia ae 246 ■^^amilv Anomiidae 252 Farail, ,^ 'i ilidae 2 62 family 'Dreicceniidae 265 Family J ;:lid.&e 207 Order Aiio:r.alorlesDacea '''-D 7amilj? Vertioordiidae 269 ~'BTi\il.i' "Poror; . _ _,g 275 '•■:''■'] ■ - ' " ?viz''^ ■' ^ 27 6 •^rder Teleod&uiiiacea r: -^ Family' Oraocatelli ' £ :;, ■^ c , -•' i '- \ r"; r, o 294 ?aniil^/ Gliaiiddae SCO T'a.milj" lU',; ■ ,. : . family Diplodorxtidae "'"'- ■^amilj' lept onidae " ?arail3i Sportellidae T'-r ^amly T^elliellidae ? S07 --1 _ . orally "^ardiidae 5T59 Fanvlli^ Tenafacidao ? ir.'-'" Tanil^ •. ^u rl, , i37 .?a.mily Cooperellidae 'r74 family Tellinidae 47 7 Tamily Seraelid ac 51C family Donacidae 515 li'amily Solenidae '13 ■^amily Ilactridae '^■'\2 "^wrnilj? Heaodesmatidae "->:"" Farnil:; 0 orl^uli dae 525 ""ar.ii^ , trocbaenid,:,e ""G ?arnil, ■ idae 538 "^a-Tiiily Teredinldse ' r.' 7ita - - _ 1 - The present work offers s detailed study of the pelecypods of the riahest mi'l-^ertiarj fauna -cnov.'n in the Antillean reen toward the solution of the many dispiited issues of 'Vest Indian stratigraphy. The grouping of tlie general considerations uaider three headings i'las the disadvajatage of postponing the express- ion of the significance of certain features, but an obvious ad- vantage lies in the segregation of elements and relations that are salient from r^ifferent points of view. In the systematic discussions •;revioiTSly described forms are redescribe . v.nenever it is considered necessary, not only to remedy deficiencies in the original diagnoses, but also in order to establish uniform- ity in the employment of different terms. In the list of occur- rences mider each species an attempt has been made to assign each occurrence to the nroTc-r authority exce"ot in the c»se of the geographic and bathjTiietric ranges of the .-cecent species, which have been obtained from a catalo°-ue, conpiled by I'iss Julia A. Gardner from vario":!S sources. AOIOrav LE lf?I]?_TSi:T 3 . The '.vriter v^ishes to express his great indehtedneso, first of all, to Mr. E. 7. "Berr^^, of the Johns Hopkins Univer- sit^Z, at whose suggestion the investi^o-ation w?s initiated and v.'ho h3S heen an nnfailinp- source of inspiration, as well as of assistance in the solution of difficulties at every sta^^e of the work; to i:i:os Julia A. Gardner, of the Johns Hopkins University, for the use of the unpublished results of her extensive work on the later Tertiary faunas of Virginia and the Oarolinas, v/ithout 7;hich many important relations t'^mI-' vryg evaded con- sideration and also for her generous assistance in the deter- minations and in the interpretation of the hroad aspects of the fauna; to Kr. ./. B, Olark and the other nemhers of the faculty of the 'Geologic al Department for the opioortunity to pursue the investigation and the training that raade it possible; to i;r. .. ... Vaughan, of the United States Geological Sujrvey, whose suggestions were valuable because of his wealth of inform- ation concerning the Antillean and adjacent regions; to Mr. '.V, H. Dall and I.Ir. Paul 3artsch, of the rational I'useum, for court- esies extended during freojient visits to the Kuseuni; to Hr. H. A. Pilsbry, of the Philadelphia Academy of ITatur-al Sciences, for c^^c-'„o3 to type riaterial; a,nd to ITr. Stanley 7/orden, of the ■'aryland Geological Survey, v.ho prepared the ::aterial and '.acie the nreliminary determinations. _ "X _ iii:i:.^ODi^2ioii. The marls e:rposecl "between I'orant Bay and Port Mo rant , near Bowden, almost at the soxitheastern corner of the island of Jamaica, have 1o:f oeen kno\7n to contain a reraarkahlj/ rich and splendidly? preserved molliiscan fauna. In 186E llr. I^ticas Barrett, then the Director of the Janiaican Survey, deposited a collection of the niaterial in the British i.^eum. (l) A fl). '^uppy, B. J. I., "uart. Jour. -eol. 3og., London, vol. ES, p. 281, 1866. See also The Geologist, p. 275, 18C2. year later T:r. Oarrick D. lloore (2) suhmitted a report on ^:he molluscs. At different times V.r, R. J. lechmere C-uppy (3) has '2). ^'oore, C. 'f.. Quart. Jour. "-eol. Soc. London, vol. 19, pp. 510-5ir5, 1963. (S). Crup-oy, B. J. L., loc. cit., ;rp. 231^2 D?^ 1866; C-eol. I.ar. decade 1, vol. 4, pr>. 496-501, 1867; decade c, vol. 1, iDp. 404-411, 43?-446, 1874; vol. 2, pp. 41-42, 1875. published descriptions of species from the "I.Iiocene of Jamaica' Ap-oarently most, if not all, of his collections were obtained throufh Ilr, Vendryes, of Kingston, Jamaica, ":ho has confirried the impression that the imterial came fi-om Bowden (-i)^ and his _ 'I- _ trpes are now the property of tlie United States L'ational J.-n^eiun. I.'Ir. Robert Ethe ridge in an a-pendi3c to the report of the Jamaican 3in*ve27, discussed the faiona (5). Gunpy and. Dall in 1396 (6) {%]» Hill, H. J., Bull. i:us. Oom-ot. Zool. , '-^arYard, vol. 54, (,c-eol. ::. \\ ~. ^ :?, 1899. ( "- ' . Etherid.£e, .v., /reports on ' 'ology of Jamaica, Part 2, '.'/est Indian Purvey, Hem. G-eui. oitrvey, Great 3rits.in, ap. 5, -op. .^.19-5P9, 18 59. (6). '^^'<^VV'S , -'• J« J^»» '- -^i-'''' ^all, ... H., a:::oo, U. 3. I'at . Mus . , vol. 19, no. 1110, r^v. 7,07>-Z^Zl , 1896. issued additione^l descriptions, hased on Guppy's material and also on a collection Made for the rational I'n.seitm by I^essrs. aencterijon and Simpcon. iJi,irin~' the course of hie: reconnaisance of Jamaica I.Ir. Robert 'P. Hill also n. de a collection and the report of his investigation contains a rather "enn-thy review of the mistakes of the members of the Jamaican jurvey and others in the correlation of the Bowden and other he's (7) and also a (7). Hill, R. T., lOG. Git., pp. 9-14, 8 2-84, 1899. notice of the molluscan and other elements of the fauna (S). (0), Idem, pp. 145-152. In tlie monumental 'Jagne r Institute Papers, Dr. Dall fl) des- cribed manj? nev; species and noted the occurrence of previous- ly" described forms; tlie last fascicle also include" ^ '-rief discussion of the fa^ma and a check-list (2). (1). Dall, v;. I-I,, Trans. '.Tagner ?ree liTst^ 3ci . , Philadelphia, vol. 5, pts. 1-6, 1890-1903. (£). Idem, -':. u, pp. 1580-15 ?T, 190S. The i^terial for thie present study has been furnish- e'l by two collect ons that are the property of the Johns "-^^op- kins Universitj/; the one is the result of several accessions to the valuable assemblage of Tertiary rao": luscs nade by Mr. T. H. Aldrich, of Birmingham Alabama, the other a collection obtained by -Dr. James E.'Duerden, now of P.hodes University College, Grahamstov/n, -^outh Africa, in' 1899, ',7hile he vras Curator of the Musexan of Kingston, Jamaica. Tlirough the kiiidness of the Mus- eum authorities the writer lias also h. ^ess to the coll- ections housed at the rational llusemn. — D - ANAXYSIS 0? THE ?AU1:A. 1. Biolopi ^al Anals"si:5. DuriiTgr the coiirce of the present Btiidj/ 3 9S upeoies and varietieG ^'^ p-'-lf^ey -^'-'^n t "ve oe en recop^xi,.^-.., -heee are segregated into G4 genera atiu 40 families. 7ine of the speo- iec are indeterrninaTDle and 83 are ne'Wi Perhaps .. ' .gle locality? of the reLativel;/ v/ell-Tmovm Tertiary- deposits of the Coastal Plain province of the Ur.ited States has yielded a bivalve fauija of such extensive proportions, although the /^liocene marls "-^^serl along the 3aloosahatehie P.iver in Florida have furnished an equal lumloer of species and the entire oelecypodan asoemhlage of that fauna and also of the I'.Iiocene '"orlctown fauiia is greater. To other explored loealitj^ in the Antillean region has revealed oji equally prolific fauiia, but it must be remembered that, strictly :3pesfein?r, the paleon- tolo'-'ic investigation of that irit'.iei.- oiiii: cuta htis but begun. It is fortuimte indeed that oonoitions of '_ mentation during the deposition of the 3ov.-den beds and siibsenuent events were of such a nature as to furnish an optirium .uetting for the revel- ation of the character, of an Antillean raid-Tertiary niolluscan faui.a. The Prionodesmacea play a siirotisingly importaiit role, being represented by 79 species, more than 40 per.exit of the entire fauioa. The tasodonts, vath 44 species, are larp-ely' _ 7 - responsible for this larp-e numlDer aB3. r;hen their relative position in the constitution of the continental Tertiarjr fatmas is considered, it i ^v^^e v^ '"'^•-^ their position in t>e Bowden fauna is -uiisurpassed. A minor element in the tasodont asi^emhlage is furnished by the seven species of the genus le.la. a nunher which is, hov«ver, relatively high, in accordance v.'ith the general consideration that the Antillean mid- Tertiary faunas are moi-e populous in members of that genus than the ap- proxir.iately equivalent fav: • '• -^ '-" ^-uii .i.^crican continent. 3y ,f ar the most iraportant tasiodont is the genus Area, with 28 species, distributed am:ong 10 sectio..... Indeed, this remark- able diversification is one of the salient features of the famia and is not rivale'' among the continental faunas v/ith which cosiTjarisons might be ^".ade , not even the rich Oa.loosahatchle fauna being anite equal '.,i jn x-u^cix-' io uui;. cxc-ieiit. In the midst of such marked efflorescence it is ■ that the Oui.earcas, which usually occupy a rtosition of importance in the raid- Tertiary faunas of the Anti:'le-n region anrl its perimeters, are represented by a single small form, and the Nogtias are en- tirely absent. rhe Scapharcas are the most ab-tmdsnt, both indi- vidually and specifically, b^it j^xl^ ui.i:^^^ oi. ^ue nii. cies are unusiially prolific* In addition : o this numerical importance the taxodonts G0'--r-:ani attention because of the presentation of some imusual feat.-u-es, .jo tliat it ;jee;iiS advisable to propose new sections for tliT'^e ,5enera- ITucula, Ler"'a and Area. Among the prionodontG the Peetenc are subordiiiate only to the Areas. They contribute 1.3 uoeeies, representinp- ..eyen see tion§, among which are inclucled virtually all the groups that would he expected in a tropical feu ,a. The Aeg.iipecteriS are the most prolific and include severe:! .^.eciuG that are widely distributed in the AntilleSn region. V/ith regard to specific diversificatiDn Ghlanys c. s. is almost equal to Aequipeoten, but o^ii^- one of the species is abundant. Jne of the interesting features presented by the Pectens is the occur-; rence of numerous valves of a STne.ll, delic:;tc Pseudamusiurn and also a single valve of a Propeaniuuiuni, la'-ter being rather rare in the fossil state. The oysters form a puzzlin'^ asrenblape, for they are few in number in all the collectio-is available ax^o large ior:;is are notably absent. T> e small siz- eworthy when it is consid- ered that especially in the Santo Domiri>-'lan fauna and also in the Alum 'Bluff faunas a uoeoie;; that is considered identical vn. th one of the Bowden f orm-s reaches an imposinp- size. Since the same condition obtains in all the collections it may probably be asrumed that the indicated relative importance of the genus is approximately correct, a] h it must Idc remerabere' that subseouent e-oloration may reveal the presence of lar-e o:-;..ter beds, in cop-neotion with the STiiall size of the oysters it is interesting to note that an xinsually larp-e and oonderous Santo - 9 - Domingian Spondyliis nresents a depauperate aspect. j '2he famil;. rirnidae iiialudeo, in addition to the con- raon 11 nia , the rare Tlmaea. Likev/i se amo .lomidae is fouii'^. the nricoramon rlacimaiiomia, as well as th^ -^'nir-i- American ibiorrla. The genus Preissena is also infrequent l;y encouiitered ,-amang'^ -i Tertiary faimas, due probaTDl;,^ to its non-marine habitat. Of decideril^' frreater interest is the oresenof ^v r:he •^-■-■nreriielj/" rare Julia, a genus which at the preDeii;.' time ia coiixiiied to the Pac- ific region and is represented by only a few fossil species, one having' been describe ri frovi the Ohipola mart ^--'Vi '-.^-lo from the Aquitanian of France. The Anoiaalodesiiiacea, vTith five species, are confined to the super family Poromy?^'^-;^ -rfi n-.-m •-.-■'p -.:'^i-^^ ''mall forms under the families Verticordiidae, i.-orOiayacidae and Juspidariidae. i^ecause of the unusiial dentition of one of the tv/o soecies of '^ Ouc'oic c.ria. "--ll 1.^^, _iropose''? ^ V'-'--' rvrnc'^-r-pv- -^ni- -; '- .ption. Taturally the Teleodesi.-acea inclur;e i^he bulic of ! the ff;u a, ;bxxt the expect 'iority of thiu niost hip-hly specialized order is somc..^^ ^; adujiibr'^'- '•'' by th -^^ :.-:-!r-i>,,-. r of orionodonts. Among the Astartacea members of ol.i ' ly j Astartidae are conspicuously , ;iile the ;lli- ti "oo pxe represented by fiv^^ ^-oies of . _: , ^'tell i ,, .. , : the most interesting and the uiojt a'; -t belong to the sao- \ ?voij.us Oras cine 11a. I'o G: . , s Yenerioardia includea a orolifio- Yenericardia s. . -d also a snBll, ourio c fox'^':! that has been referre'^- to thi """ Tomeri .-i , ctlijiio ^ - ^ uiaai - 1.' 'ji-c:.[j |_r;)ujj. One of the most stri'ring features of the faiina ic the inciiviclxial abu.. dance and ope o if ic diversification of the Lucinacea. Although onlj- five genera are includerl in this siip- erfamilj/, they are represented "by 52 species. The eezius Fhac- oides , is the most important contribu-tor to this assemblage, it alone furiiiohirj:- half of the apeci^s, distributee igbt sections. T":o phacoidan elements, Lucinisca and Ivliltha, and the .freniio I no i na , all of v;hiGh might be ex^iec o be r)resent, are abi^ent. rhe Jodakiac and ■--—^-- , : ^^ abiu.u^u.o cinv. v/ell-divor- sified, while the Divaricellas are individually nuxnerons and the 'Di-nlodont as, though including- four s-Decie:, , . . ^aual, repreL-eiiUed by a small nvjiiber o± iij.- iv iduals. The meager representation of the leptonacea stands in decided contrast \^ith richness of the liicinoid element, the entire suoerfanily includirig' only four specie^, ; - •.■ited into three genera and as non'^' families. Sven more than the K-mall number 6f s-oecies is the fact thrit t ' -' are re"'recented by a total of only five vs^veij. .-m intercj iixi^- feature is furnished by the presence of a form belo: secti-^-;; "pnterotia of the _,-- -. ^^ : odonta. - 11 - Thg 2:en.v!G Jarcliiim. i_ ented \)2: eleven L/pecie.3, grouped into seven see-^i-ns, raiirs aniou?'- the lar-c renera and v/ith ;.lie ov/u rxoi/Ofjc'-riLituu ohe faiail^- jaj-'diidae 11; elevat- ed to a. position of iriportanee. The sections present are thoce that are foiind in an^,^ troriical or sii-otro-oical rjid-Tertisry imericaLj. ia.a,.a, but Jctc^.l; uoderraa and Pa'o;yridea are not included and the Trigoniocardias, vfoich are peculiar to the min-Americaji and .'jitillean rer-ionc, are a conrrnioizouG element; in fac!;, :._ of t;-e jrigoniocardias is the meet abundant bivslve in the entire 2he nost -ouzzlim- form is a small ;:.-«ci • ''- -VL-evlous- Ij^ was described as Sja immatiTre JLnomalocar ^ia. In the light of the additional material at hand, however, such a vit able and it Is' vjroriosed to consider th.is v^ x^cirr +;^, of' £ new genus v/hieh ' .lestionable xDlacel among the Isocardiacea, probably near the familv Vesicomyacidae. - The family; 7enerifl-e -:-irer'er.tn r m. thpr ■;ini--5^1 ascem- blag-e of genera and species. Jhe genera are divided among the subfamilies Meretrioinae, Venerinae aiid G-emminae, the majority belon-nn^ '-o the first of these. The genv;: Chi one i^ -i e -•-)Et abun ant, ;vith regard to both the n ytfoe r of soeei : indi- viduals. Para^starte, represented by a single valve, has here- tofore not been found outside the Ploridian rp^-i^'-, -either re- cent or fossil and ^ivcla does not aoorar in any of the other - 12 - American Tertiarj: faiinas. Another interestinp- le- tra*e is tlie . ocG"arrense of a foim that ap-arently shoiiLd be pliiced in the genus Oooperella, from the t^'pical form of vAiieh it is sepa- rated "by differences that are of at least sectional value. Only two s-ecies of the genus have heen hnown, a recent soecies "rom the Vest Ooast and another from the I'iocene of the Atlaxitic Ooast . The geniiB Tellina also must he placed among the import- ant genera, for it includes 15 species, distributed among siz sections, Angul-^;'*. I'n.s thft Ip.rp-est number of s-oecics to its cre'^.it, but the most cbiuid aiit forms are foi" er l-erisca and Koerella. ?he other Tellinacea present no unusual featiires from a biological -ooint of vie'-. The reniaining- ^'eleodesiriscea are scattered among sev- eral groups, The suoerfamily Solenacea is represented by a sriecies of the genus Psarimosolen. A sinp-le fr: -'nientejry valve belonging to an indeterminable s oecies of the genus 3pisula is the sole representative of the i'aotridae. The Gorbulas are the only non-boring Ilyacea presc-., . :., ."'thour-h ine"^ r'-'!1--r" inly three species, two of them are ericeedingl^j prolific. ...e un- usually favorable conditions liave -lermitted the ^recerva-tion of several b-^riii-' "droraacea that usually are not foiu.rl in Tert- i ary f aunal 1 it t s . - l."? - 2. 3eological Aiaalysis. The 0 tiident of recent marine faunt-o u±oou!oly would view with grave : ' ' ' an attempt to recorustrac t environ- mental conditions on the basir of the testimony fiirnished hy 8 oingle element of a fa.ima o.ii\ it must he •r-'''''^" '■ted that Guch an aVcempt is e-:tremely hazardous, the natural tendency heing to overburden the scant evidence in the -^.es: formnl^.te more 0.: lecG definite concl ..;_, io:.;:. . i.i.u ciL- c^j-in^ ■Jiii.i^uxs are augmented b; isfactorj" condition of the available' in- forma,tion coneerj. he actual and relative importance of the factors conditioning the ut'^j.-fc ".s.tion o::. ii.-^t.les, of which the three moot importajit are t::e cliaracter of the bottom, tempera- ture anc' depth; it . :e remembered, however, ': ot'n.cr factors may have a pote.-b influence on the distribution oi a certain form and that the several elements ma.y be intercorrel- aterf or may include subordiriS.te considerations of greater or less moment imder different c o.-aitioiiS. The paleontologist who desires to deduce conclusions concerning the ecological condi- tions that determined the chcracter of a ■~r-e-e:Ki stinr fr.una is at the very outset disherirtcned by the serious dearth oi in- formation concerniTig the actual coiistitution of existi _:] 1- ow-water fau^ias, to ^'Sy nothing of the effect of different numb e r bottoms, for by far t -e greater of fauns s that receive his con- - 14 - sideration have floarialied in either relatively or aetiiallj:' shallow water or even in the intertidal zone. Dredging op- erations h've 'oeen conducted for the most -oart in the deeper orf-chore vaster and even then a source of confusion has arisen throv.gh the unfortunate practice of failing to disf ' :h the occurrence of dead -and living forms, ^or ohviOTis r .: it is often impossible to determiiie the texture -- " '-he bottom at each haul even in shallow water, co that the knowledge concern- ing the influence of hottom conditions rests largel3; on what is kiiown concerning the '"^istrihution ia the intertidal zone. stud 2," An intensive of a restricted shall ov7 -water '.Vest Indian area, such as the census conducted b" the ?ish Commission for Vine- yard SoTond and Buzzard's Bay (l), v/ould be o^' x.^t; stiriiable value (1). Bull. Bur.' Fisheries, vol. 51, pts. 1 and 2, 1915. in projecting backward the conditio. t determined the assem- blage of an Aiitillean Terti: _ :ina. Desnite the difficulties i;'^vc" - -^ "'jhe ensemble of 3o"den pelecypods is such as to pe-rmit the offering of certain considerations, soiiB of which are more or less obvious and even trite, v/hile others are to be re^rarded with some reservation. It is of course, a m.ere platitude to state that the fauna is tropical, since such a facias is to be ezpectei-i from the - 15 - geographical position of the deposits that have heel the faiiiia; ;;"et this aspect is emphasised in a striking imnner hy the extreme development of certain groaps and the ahsence of' others that are prominent in the Tertiary- faunas of the At- lantic Oos.st. A mere glance at the faunal lis'; shov;, '■'-■- 1 the most prolific genera. Area, Pec ten, Phacoid es, Oar^j_ij^ and Jellina are characteristically tropical or are represented onlj b^ sections or s:^ecies that are confined to lo- "• '"itudes or there reach their mazimtun development. Aocording to the latest faimal lists only t'TO of th 18 oecies that -oe raits to the riecent at the ■ore^.ci.;. ui.-c -"-r'^-g ^'^r-'rh of >'"■"- "atteras, the uhiqrdtous Anomia simplex and Pi varicella g-gadrisulc ata ; eight are found from Hatteras southward to the V/est Indies or Brazil; seven are confii'ied 'jo the area south of Florida and one soecies is restricted to' the tropical porti :ns of the '.Vest Coast. Virtually the same proportions obtain for a la-i.'~e nuxjber of recent species that are closely related to certain Bovvden forms. One of the most striking features of the fauna is the lUiUsual develooment of the Areas, a /lat attains its greatest irapor ta-ic e in the wnrmer l' e ,; . The species are such as might he e::pected in tropical waters; indeed a number of them are encountered in the --iresent Test Indian fau. . ^he genus Pecten is usually a conopioaous element in Ter"'""''"" '~'"'^ ^ece'nt faiiTiSS of almost all latitudes, but the ]a.rge species that are - 16 - Oh araot eristic of higher latittides, suohas the forma v;hiGh frequent- ly' form, entire beds in the Torlctov.n T'iocene, are conrjpionouG- 1^S ahseiit. Although individuals of the genus Spondriuij pre no"^ numerous, they are divided among three soeaiec; the genus is at present c'oniined to tropical or suhtropio al regions and is relati'-ely rare in the Tertiar^.^ famias of the United States, all of the ocourrences in the middle and later Tertiai'^: . faunas hein- restricted to the U'lorid.ian area. Perha-ps the most obvious ind.ieatlon of temperature conditions is furnished by ths Astartacea. I>/en the v/arm-water Oaloosahetchie and '.Vaccaraaw famm ;-3' include one or two Astartes, hut in the 3ov/den assemblage the genus is entirely absent, the superfc-mily beiri^ represented only oj several Orassatellites, including three species of the subgenus o r q o - ' -^ ^i i ?, . "'■'n^- -ponder- ous valves of an Schinocharna, a ^-enus vvhieh is at the -resent time oreSminently Antillean in distribution, are a very conspi- cuous element. It has already been remarked that the extraordinary development of the lucina.cea is to be considered one of t'-^e not- able features and it is significant ;_..^^ the entire group is O-iiite partial to tropical habitats, although a few species, especially of the genus Divaricel] a, range into hi^h latitudes. -0 other superfamily, e::cept the Arcacea, presents an equal numbe 1- of species and from the point of view of the miniber of gnera and sections among v.hieh the numerous species are distri- buted this group i.. .^...urps.ssed. -he genus Oardium ic represented 'oy a latge munloer of species and an over-.v^reli:.' .- '-^rity of them are q- ^ e t^.oe that immediately? in^i' a warm water habitat; ?''^ the smooth or relatively simple forms are identical v/ith, or olcrje- ly related to, reoe eeies that do not occur north of "Florida. It is not cm-prising t>r'- memberr:- --f the section Oerastodernia are absent, since the groiip is for the most part confined to temp- erate regions or comparatively deep water^ but, as far as cond- itions of temperature are co-'-cerned, the subg-eniis Papyri de a wo uJ,d be e:cpected to a-^pear in the faunal list, yet it also fails, probably because of some unrecop-nized ee ' ''p-l condition. A discussion of the ^ ->•■■-"'-- -...16. be incomr^lc .^ ..i'jhout a refer- ence to the amazing aburidance of a. Trigoniocardia ■; is prod- igality is of added significance when it is consideTed that the -roup is restricte-:! to the .-..-aillean and •;:! - ^,.t. ^ ^ icni areas. Although the distribution of the genus Tellina is almost world-v/ide, the grou 1 .ly tropical and therefore its e:cteneive development irely another indica- tion of the conditions imder which the Bowden fauna flourished. Difficulties, both snail en^ • reat, involving various factors are immediately encountered ..;:(iii lui attempt is made to ■-amiine the bathjmetric conditions from a consideration of '■he ■ abitats of the Recent species included in the fauioa. A rigid aaaerence to the evidence :? -eil b^ the dredging re- cords for identical or closely related forms would often lead to surprising, if not ridieulou:-i, conolusions. An e:^ample in point is furnished 'by the " _ ! iniopc ie, of which '" n -secies are present in the fauna. Ac-eordirig to availabl: ■ the group as a v;hole is characteristic of deeper water and 5^et several 3'-)eGies occur in Eocene beds of the CTiilf Ooost that unGouhtedly v/ere deposited in very shall-: ^^r. The failure of the gem^ to appear in the coiitinental Oligocene and later Tertiary faunas has been ^-:"-i:'e- by appealin .allow- ncs..: of the water, but it would not be safe on this baais alone to conclude that the 3o~den v/aters vrere of considerable depth. The fauna " ° 'sentiall^ a .i'lallow water-faib.a. All of the recent species at the present time occur in water of ;-'light depth and them have been recorded in the inter- tidal zone, btit th^.. :lc. , ^,^ e:rtendc'- \ to consider- ably deeper v;ater. The presence of apparently deeper v;.- ter elements, such a;- ■ .^ 3at?iyarGs:. _ be the result of the action of currents or other extra-ll-i'tal factor,.. Since but a single v ^ :?indaria is yjresent it may be doi7hte' whether the form is indigeno'^is. Until the se'^iments are studied s'r^ '-^'.e evidence of of^-- :■ lOiipu of ur^v;.iiii_:iiib con,_ Idered , it is uiiv'ise to attempt to even roughly aoproxlmate the depth of the water, but it may be ':he de-nth -^.i'-'' not exceed 30 or 40 fatho..!,. t<^__ -. .; ~-^ -, - __-_■■..-.-„ ,. of the sediments were deposited in water th: ^ considerably - 19 - shallower. Even greater TJuicertainties attend an effort to po.st- ulate "bottom a. - . . I-'; :her definitely statef''., however, thab 0;^" _ar -j..e ."reater ivejorit^' of the pele- e^.-pods are partial to "bottoras oompoeed of sand or fine gravel and therefore it may he acsi^ined th-at in-general the waters were clear and the bottoms frei " ai mud; even the hurro\7ers are those that are usually found on sandy hotto . In this connection the absence of I.'ulinias and related fornis that pre- fer a mud-'. y bottom is not without significance. The few n.iid- loviii ■ bivalves present probably had their station in estuaries^ at the heed of which lived the brscTrish-wator Dreissena. Th.e small o;;ster that is consiaered identical with the recent man- grove-oyster, £. voliiijp may be assigned to the same habitat, if its habits were the ::;n.r:e as those of the recent form. The meager representation or absence of the small j-'eptona.cea and other forms that usually frequent . \ . - in sheltered near-shore nijositions or attach themselves to algae, seems to indicate an open coast and rather strong current action. It appears that the greater T:art of the coast was low and interrupt- ed, ?,f. indicated above, by'~gr---few estuaries, ^'IT''' r^ro by head- lands, since the coarse teiitiire of the eedii,ents ';:estifies to rapid erosion in at least part of the area and the nrorrimity of the vni -anic debris from vrhich they were derive'.'. _ ''O- 3. Geological Analysis. The correlation of the V/est Indian j^ertx&ri- deposits involves a somewhat complicated history? v/hieh will he briefly considered only in so far as it has a direct hearing on the opinions concerning the otratigraphic position of the mollus- can faimas of the Bow den and approximately equivalent format- ions. In the etrlier, pnd , stra".:ge ,: y, even in the more recent, literature it .. ".^e imfortunate prt/juije to care- fully avoid the assignment of oolleotions to d.efinite loc- alities and therefore such vt^.r-ie statements as " Jrvii.aica", "Hio- cene of o"'ar.:iaiea" and ''Oligocene of Jamaica" are frequently encountered. In tl^e case of "Jamaica" as ippy there is lit'-le, if any, uncertainty concerning: the inter-oretctiou, since it is definitely knoi.^n that hi ' ' . ■: ' ' .is came from Bowden an-' eumahly his usage was in conformity with that adoioted hy his confreres. The mollascan faunas; in question '.vere referred with general unanimity of opinions to the KLocene hy Moore (l). (l). Lloore; 0. J., aiart. Jour. Geol. 3oc. Lonr'on, vol. G, ■op. 59-44, 1350 (Santo Domingo); vol. 9, op. lS9-lsr. , 185:5 (Santo Domingo); vol. 19, pp. 510-51F, 1863 (Jamaica). - "1 Guppy (1), Ether id£;e (£) and Gab "3 (3) - Upper Eiocene to dis- tlngiiiiih them frora the older I'iocene faiiai&s of Aiitig-ua and fl). Gu-Dp;.-,. .■!. J. L, , ."uart. Jour. Geol. Soc. london, vol. 22/ :'p. £81-286, 18t6 ( Janaica) ; pp. 570-579 (general); Geol. Mag., decade 1, vol. 4, pp. 49G-501 (-^-eneral); decade 2, vol. 1, pp. 404-411, 4?''5-446, 1874 (f;eneral, including a check-list); Qimrt. Jour. Geol. 3oc. London, vol. 32, pp. 516-518, 1876 (Santo Lominrro). Cuppy has expressed the canB opinion in numerous other oapers that have no direct re"^ at ion. (c). Etheridge, .. , .eports on the Geology of Jamaica, pt. 2, ■.est Indian Surve;', I.Iem. Geol. Sur.Gt. Britain, ap. 5, pp. S11-S29, 1859. (S). Trans. Am. Philos. Soc. ITewser., vol. 15, pp. 95-102, 187:^ (Santo Domin^^i-ol. Trinidad, the latter bein'^ cubsecuently considered Eocene "by Gu.-^py. These earl^' inve;. '.- ' 1 ' vere conducted before Bey- rich had differentiated the Oligocene or before the concept' of a disti.'Ct Oli'iocene transgression or transgressioiis had re- ceive general credence aiid it v.-as q.uite natiu-al to consider "..e faunas liioceiis since th.ey occupied an intermediate position TTith reference to "'.'oc r-ne a"rd ''^lincevie faunas, altho-i^h most of 'Che fo/i^^s that were assigTieci to ..eoent species have he en sep- arated from their existing- analogues by the later sharper def- inition 0^ ''--^GlfiQ liu-S. From the very inception .- ese early studies the close relation of the faunas to those of the Tertiary deposits in the vicinity of Bordeaux in south- western France v;as emphasised. In £ orle'^ ■•'-':'-'?■ ^ ent h^ Ooiirad in l-"'" •'-';t'7 "'r,]\e Oligo- eene has ''oeen foa^id in ob. Domingo" (1) ic loi "c- rerence to the ence of Oli^'ocene in the .'/ect Indian area; (1). 'OorJi-ad, T. A., Smithc. Ilisc. Ooll., vol. 7, no. £00, n. 57, 1865. the 0"oinion n an eerlier : ':o go e cert;: li. ^...:;0 -'O: ' ' a '.^t;.'y,_l , ■-■\'-'>i (?). Conrad, T. A., . . _ 1. Hat. 3ci., -1 , or 1862, ■- o-g. 198-199, 186E. then v/ere Gonwid-ered Soceue. "roo ( ' , ... in r,ll prohahility correctly-, prot.. ainst this corre" {?■). Ice. -■., p. 97, 1P7-. G^re^ory s/^'^arcntl;? v.",:g the firot to o-a^^- st -le vorio r; out ore ^3 01 j.iallow-water ;:S. rine lie^i:.. positions in different i; " ." the Ies;ver ilntilles afro are all f ro'-rnent D of widespread Olin-ooerie depo ) (4). Greg-orx-, r. .7., Quart. Jour. Geol. 3og. London, vol. 51, p. "98, 1893. Q'iic'- t lie re is no reason to nn.ppoce that he wou2d not have ap- nlied the same statement to the Greater Antilles^s if thej? had been miCLer discussion. A :;ear later Dall, (l), v.ho iu quoted (l), Gu-.ipi , ?L. J. L., an;l Dall, ./. K., Proo. U. S. iCat. I.Iu:-. . . vol. 19, vn. 7n^-'^C4, 1^96. hv American excl egorj/, brief- ly asserted that all of tL., .,u-co,lled Hiocene of the /uitilleGn region, as well aa the deposits of Bordeaux, should be consider- ed 01i£-ocene and from that tine dates the current opinion that the I-'iocene ":s.c a period of high uplift ' "^ '"he iintillean s,rea. At thi;:,' point i;. involve^ the questi of ther.e fro- quentlj- -jiientioned be-'s in southvre ,e. By the "so- called Ilioceneof Bordeaujc and Dax" Dall referrer^ to the Aqui- tanian, r;hiGh at that t i .e v Vioet generally considered upper- most •"'lif'ocene : Since the^i, however, m.'^ny o . ropean strat- igraphers '-ave c or. s id- red the A-"!''- :i " ': I.liocene and that opinion is the prevailin,-; one. e ?/ho contend that the Acjuitanian is Hiocene consider all of our "achicola f.:^ Iov:er Iliocene; Dossnar^a ("), for example, severely criticises f2). Oossmami, .., A.ev. 3rit. de '?aleozool., Id5, no. 119-121. Dall for callinc- the '.Lamps. ..... -..a Cli eocene, altlioap;h, as Dall (1) 'nas replied, "ooth e that it re-orecents at leact (1). Dall, .. .-., --CJ. .-_]. • . ---on, vol. l-^ , nt. 1, p. 58, 1916. the lower part of the Aqr^itanian. It is of interest to ohserve that ac Ic - -' "" .Joiiville (2), in a notice concerning (g). Bull. SoG. 3eol. France, r'rd cer., vol. 1:6, p. 58'D, loOS. Panama paleontology-, calle-'' .■^'-■^-entio-. ^^ ^>i'- '"^ot thst althonp-h the lo7'er :.art of the Bordeaux depoeito ii. ian, the na.jor pert is Bixrdigalian anr'^ " vtian, that .'. , ouote:"^ Lliocene. In oormecti on with his recent work on the foraminifera of Trini- dad (3) and Panama (4), \7herehy Is has differentiated several (5). Gompt . 3pnd. Acad. Sci., vol. lol, pp. .'.-..7, 'v.^-, 1915. (4). Oor.TOt. Rend. 3oc. CgOl. Prance, no. 19, op. 129-151, Dec, 1915. Stampian and Aqiiitanian horizon>3, he continues to -■ the rrincipr.l xlntillean horizons Burdigaliaii. In the '.Tagner Institnte Papers Dall, ■ ' ' o had r^ade a s)relininar3^ suriT'ej- of the Bowden fauna and descriher! nianj' of its new Gpecies, correlated the fauna "perhaps v/ith the Oak Orove sanrls, or "between the Ohipola and the ITioeene" (1). later (£) the faima was given a similar position - hetv/een the Ohipola. Oak '^'-rove. (1). Dall, \'i. H., Trans. ,;agner Free Inst. Sci., Philadelphia, ■vol. 3, pt. 5, p. 1582, 19 05. (2). DaJl, '. U., Bull. U. 3. Tat. ::us., no. 90, p. 8, 1915. Almost 7C per rent of the 3ov;den pelecypods are pec- uli<'ir and 18 wpec'ec, 9 oerjcer-t, persist to the l-'iecent. -he largest assemblage of forms fomid elsewhere is the group of 54 species that are known to occur in Santo Domingo; the largest nurnher in common v;ith any horizon in the Floridian succecsion i' --he 15 Ohipolan species, followed hj: 9 '.vith the Oaloosahatchie and 7 with the Temps, and also the Oak Grove. The actiial num- bers are of little significance, since a slight chaiige in the definition of specific lines would have a decidec! effect; uij^e- over^ as the distribiitional list indicates,, much is contingent u"Don the facie s of a fauna at a certa'n horizon, especially as to whether it is tropicsl, s^fotropical or temperate, tixi'.'i al;jo llo- on the extent to which a fauna has been studied. The ^lorid ian Tertiary succession, which must be con- sidered the ;jja--aard for the determination of the age of an .'mtillean fauiia, i; ;'nLfortUi:ately incomplete. The Upper Oligo- ^ \ >^ ^ ^ fv «> 5 < l\ J ^ 5s ^ N t) •^ ^ S5| »J-^ 4^ "U/ <% <\ "^ ^ ^' J ^ ^ ^ ^ ^ S> P> lb ^" ?> ^. * ■ ft. ^^ J ^ ^ ^ ^ -^ (^ ? ^ ^ ^ ^^^^ i-i (^ ^' -^ «i > <; >i ^ > ^ ft §;^^ -^ . \ ^ >j tu ■^ ^ ^ ■ I- A f-j r^ ^ .^ .^ o <-0 ^ \ V ^ ft 6r| .-t^ tj ^ ^ t^ s^ ^ V Si^ "^ ? ^ ^ ?i ^ ft I s. ft ft AS .{.■ ft ft Si" ^ ■■g ^ .^ -^ ^ I ^ g I tt j^ .i; ft 5s > -^ >, > I I ft S^ >-l -^ Is.' .^s ■X -0 X X X X X X X J ^^ Ch/po/^ mar/ Oa^ Cira v^ Jan/ X X St. /for yS form. «5 X X X X X X Ca/ifDryj/oO'/itie.t) yi-in i'dai/0'/;ee.Tj Ate>!i'co ^o/oo6ahi.tc/i;g' C\i H y^rci X X X X X u> -M N — s t ^^ ^^ ^ ^ ^- f § ^ ^ § \ r^ ^ -^x^ ^ ^ ^ ^ ,5 ^ ^ ^\^ ■ ^ ^ 5 ^ 1 1^ ^ ^ ^ ^ 1^ ^"^ ^ % ^ ^5 ^ ^ ^ t g ai 0-; N s» >-. j/; .c; .^ jj) ' » |i; 1 J yc Conncac ^ , Xs^/"^fs of Ci M St. A^ttryS/or, ft ft 1 «, «>p _ CO CD CD 00 «b . ?to --1 ff^ V-, J ^ «J « 5 ci ^ J? ^ "^ ^ ^ ^ ^ ^ ^ •V' ^' ^ i ^ I ^ ^ ^ ^ ■^ S ? ^^ I ? ? i^ ^^ ^ V ^ w s^ 5s ^ ,2^ X i>.^ I ?:^ V 5 o 5 ?i^ ^ f5> 5 ^\^ 5> >" «» ^ ^ ^ ^ C'^^ ^ .0- ^ W V ^ N K K !■ $" ^' O CD rJ I I V ^ ^ ^ ^ ^ ^ rt c> ci 1^ ^ ^ ^ « ^ ^ ^ ^T ^ V ^ ^ ^'- ^ ^ . ^ =1 I n ^ ^1 •'^co'^ TV a 5 ■ ■^ N >> % > f* t? iJ ^ y, ^ > X Co6a CoracOo J A^exici, (c/,y.r) S/">«/ Pilfer ^^ X X X X X X y X X X X >3 Ca/tfcSm^ I J ^ '^ ^ "^ r. '» ^ D '^ ■J' ^ ^ :^.:^ ^ 1% t\ .:;^ ^ ■sO Oo ^ C ^. ^- V. V ! ^ ^ ^ ^ ^ ^ \ ^ 0 ^ $ \ s^ ti ^ ^ ^ I .^ S ^ ? ? 'I 5i J V ^ ^ "v ^ ^ 1^ <^ (^ ^d^ ^ ffl .^ ^^ u, t> u, ^ «1 J- ^ I ^5 ^ <^ V£ ^s> ^ -^ .^ ^ ^ v' ft" D x^ <^ .A \ \ % i; a ft: ^^^ 5t ^ «J ^ <% ! ^ B V I I 1^ Si «> ^ ^r\ :^^ v:, 1^ % \ > Ui (w Cu ^ W J ^, ■> > \ % U, ^ Uj Uj (y «f Oj f; ^j ^ >4 > > X >< X X X X X X C< X Afex t'cv form. Cu/ccSo/yti/c/t'e ft itr ~P/e/syoce/7e _ "^l' .^ ^ ?^ ^1 ? ^ (^1 ^ ? ^ "^ ^ 5 ^ ^ « ^ •% s:' -^ ^ \ >, "> \ >. i ^ ;*" Ji i c, si .>; ^ S> S^ C^ ^ S^ S^ r-' £^ ^ .^ ?L i sL ^ .^ !> ^ i I, ^ M $ 5 $ i^ 5 ^ ^ ■ti .*; c ^' s ^' >- ?■;} i It :k 'Th Tt> %, $s ^ -^ ^ ^ \ ^ \>^ ^' ^ i ^ ^;^ > > rs cv^ 5s 1%^ N ^ ^ ^ ^ ^ V ^ ^ H > ^ K> .s ^ >1 >> >. > \ Is ft ^ ^ 5;; ;?v ^ ^ ^ ^^-N «^ .-^ _ i ■-r- Coraca c u ^' X X X CosAj AictC^/tc. T) Sf: Afl ry s f'fn,. X X X '7r,'n t'J^^ CF//4>c. I ^ T-'eru X ^ r* ^ J5> ft r-. «v «^ ^^ r' *^, § v^ $; ^ 5! B^.^^ 0 N ^ ^ 7^ <4 >> ?^ -^v^ ^ !» ^ V ^' ^" ^ ^ ^ 51 ^ 5I '^i .^ ';^ '^ ^ 's § 9 'Cm ^>^, > > > > > \ ^, (J tJ3 ^i ^> >, >, i i * Q} Cb > V. ^VI Q *^- V. ^ ^^ ^ ^^" I ^ fj n, -S ^ % > <1 R. Si "I V v^^' ft M "^ ^\5 ■b a -ii -ii -h -b :>^^J.? '^ '^ ^ ^ , . ^ ^ .uJ \4 -^' ' ^ Cto ^- V jv :^ ^ ^N. ^^ -" X :? ^^ ^ ^- ft ft X C ^ ^ ^ X X > > y- X X X Ctfba . Dak £'!'<' re 3^1,/ marf % /ork/t *r-'7 / furnt. X > >^ "^ -^ '^ ^ ^0 Co Cb Cb ct» Cb ^ .^0 5** >* r^ Vt \ ^ ^ ^ f - 5:. ^ ^ ^ ^ ^• 5 > ^ So ^ ^^ * ;j > "^ :}, 1.^ X ^ >< X Cu6a OaA CVcir^ Son/ S/ioa/ iCrcr a.3Ji >< Costa ficaO^/tc-l St, /*!ara s f^rm. X Mexico li/acC .:-^ic- .., ' .ignif leant ^'':- :r^-' of the groupri have closer affinitieii with Duplin and c ■^iccaraaw and Oaloocahatshie forms. The more important of the^e modern elements will he mentione-". 'The tarrondonts supply one-third of the total numher of Recent species included in the Bovrden fauna and all of theoe are found among th^^ :^-... c, " -f-v.-^-f- -^hoi; ^--mil^ , eeiall^: the suhfamilj' Arcinae, ha 1^: mo^ .s:ect. ?i7e fiecent Areas are included in the list and several others, A. ( Irgina) toleoia v; r. microtert, .. (Ounearce.) o"othanta and A. ( ocapharca) prephaina have very clOGely allied P.ecent forms, ^rhe mere ntimher of Recent opecies is of minor i:-portance .:;iace four such are found in the Ohipolt. .\^.^._ ' three in the Tam- pa. A modern element is, however, furnitjhed hy the introduct- ion of the section Bathyar^a. - The most ahuvidant Area, A. ( 3cs.pharca^ halicTonta i ;. oloi^ely related throu?:-h its v.-:^riety hiapaniolia to the Iliocene and ?lioce-\e lienoca and the Recent secticostata. lY'O of the three oyGt'ir:^ -v^ oelieved to he i'-">"- cal' with Recent g-oecies. If the synonymy for 0. me god on it aceeptea.this species furnishes one of the interesting example f; of a fc ■'istribution on hoth £:ides of the Isth.ra.. of ''^anamc and a -oresent restriction to the Pacific aide. The occurrence of the 'ReoQ.nt nangrove-o^ster, 2.- foliuri, in the '^ov/den faaijia is Gomev/hat Gurprisincr. The Veoten^ Ir^oZ --^-;"-l elemen': re not knov^ii amovig the ^lori '. 'er Gligocene famiaa, iiuch as T, (Euvola) ho-denencic , ^. ( Aer ujoe 3ten) rjumpleua. and P. ( Prop-- eamuaium) s-3end^:l-.i:';. "^'"^ -i- "i- membe':" ■'^~ '"' ^- ^-ennc, P. ( Aeqiii':;ecten^ inaequalis var. cioutipictixE all he considei variety of the Piecent P. raayaguenc ' . -Ithoarh the section Pro pe anus lum ^'"' "'"-^'"n from the '< .oeene, the Bow den specie ' "- ' form foiuvl in the present V/est India: . \ition to ': - ., the Peotinacea Bupplj' another more modern element in the ioit.i of Spond:;lua inoiVoiu:^ , ' h ma^^ be the iom\s of the Recent echinatuG. Among the remaining Prionodesraacea the genera 11 :-,ea and ?lacr.^'a::oyua are luirepresent ed in ^ ^.^ -.ligocene of the Jloridian uection. Almost all of the Anomalodesmaoea have modern aff- inities, h^^t their tectinony can not h^ve '^'^--^h --^ -■'■''•■' t sin^e the genera repi'ecented ar ' es th. 'e heen rather atahle for a Ion-- oeriod.. Of the five L;oecieK of Oraosatelliteg -' ^ '"-■'^ "-^ot ,^-io:_ ir.g to the section Scaiahiila are verv cl: " relate^l 'oo Jhlpolan forr.ic, "out the ^ren-inellas, es^-;er;' Z, xenns, are d- dern. A-itie f x j..i o.ie .;eeent Oha. .^; ■:ic.'.,:^.;roph2,'lla, '':•-' -T^ecence of the genus HchinoeTiaiiia lends to the Ghamidae a modern appear- - 7:^ - anee , the Bowden and Santo iJoraiii<;:ian oocurrerjoea oeing the lirot to he .encouj-itere'. The LuGiiiaeea ac c e have a more raofern aT)-oearan3.-. thazi xiov.lZ he er;";ecte:1 in the c.wo of an Up'^er Oli^'oce^-e lo.," In addition to the inf3.uence of several GpeGies, including J 0 dal-' i s.. lomonea, C!oda2:ia ( Jaronia) vendrj'e 3i and i rl e s ( Oalluoina) pi;uperatus, v.h.ich are meet closely related to jJiiplin or later forme, this aspect is emphasized bj? the initial appear- ance of the '. ection Plour olucina of the .'^-enis Phaooides, a rroti'^ '.?hieh in Florida i>j not known earlier -r:an i;he Pliocene. 5ne section Snlopia of K' rtaea. al : introduced in the Oenpa fauna, reaches its fir"t develoornent of an;: i— oortance in the Sov.'den jTauna and is i'eaent in a;'i;^ oP the po:„t- Jaripa Plori- 'Tertiarj? da fan f as. Besides, no form reremblir^ nnnt--^ n-r i ■.■'.-.-. -r- Tertiarv elements. Tivela janiaioenGiR la fclie onlT>' re ;a*e;:,exifca.tive of the geniiG recorded from American Tertiary l^eds and the Recent "afrar- ium (Goaldia) insizlare has not "been reeogniz^'-" ■:=■': anj? other Tertiary; horizon. The single Gyclinella is ver;^ close to a Re- cent epecies. Oh i one L-awlrinsi is closelj? allied to the Duplin crihraria. The genvsi Para.i3tarte, itare-orded from a ;)re-^/Ioaelle horizon, if represented bj- a specie;" that can scarcely be sep- arated from the !.'i"cene to Recent type of the gemiG , P. triouetra. A imique form is believed to represent a nev^ section of the genus Gooperella, which in Its typical form fir,;.t a.roears in the Duplin. The Tel] Liiao proper are an almost strictly i.,L^digenous group, only two of the fifteen species having- an ej:tra-Bov;den distribution, without arty striding relations. Three species are representatives of groups that per.. 1._l; from the Alum Bl"--;^ -^cMusiS to the Recent. The other Tellinacea, however, present some im- expected features, including the initiation of the section Gymatoica of the genus I\lac ..' ^-^ . recei/c .^ .r Lgilla - ■ c, Semele tliat is surprisingly close to the Pliocene and Recent bellastriata. The Ghipolan elenents in the faima are relati^-ely num- erous and not v/ithout significance. Of the thirteen species that are eo Tiion to the two faunas eight are long-ranging and there- - '^'9 - fore hardls; cervicealile for -nrrrDo^-es of correlation, the remain- ing belonging to tne follov.injj- ^.tviei^a, v/i th a ;„ ;_jt' c iu '^ Oo uiiuh ■V. genus, Phacoides, Jardi-gm. .^itlgona, Tcll.ina and ^■'■acoma. In addition to the identical species, a ntznihe r of Bowden forms have their cloiieiit ai'finitiea vvith Ohipolan lipeeiuu; L-i.uje BoV'den- forras include Area ( Soa-pharca) i ne c ui 1 at e r al i o , A, ( Scapharc a ) agnag tha, Pteria -orepocera, Pecten (Ohlam;. s) oelli'oictua . Lima stenoeo,- oabi:, Julia garcnerae , t_he t'./o Scam- bulas, Kontacuta (?) menotreta and 3:-.rdium (?rggum) elattocoGt- atuqi. There is alco a 'Dardium s. s ., a ^^'uhgenus which in other American areac is not /.nov.n to survive t ;-f -ligocene. Without any douht the Oliipolan elements are completely over.-hadowed hj- the lar'^-e number of riore modem cor-rHiituentc, especiall:/ t'loce that involve t..e livcroelucti n o£ f-'ii; irely new groups of sectional or greater valiie. It is difficult, hovvever, to i-nternret the cip-niiicance of these raor' em. element s v/ith re- gard to ape relation:-. 3i:iee the 'i jx xcsunal facie s is in- volved. xany of the post-i-Ohipola elements in the Bowden assem- bj ;:--'e "re fojv.^ri amonrr the chsrseteriGticall:; tropical gro ' d it r:iay oe contended that the later rertiar^ aspect of ti'e .L.una is due to the fact that is a strictly tropica" pjia, the first America.n trooln-..l fanr.a of any im"ortance that hac reeieved consid- eration. It muct be rememberea aliiOi tia^^ t^iie ^hipj-i.;-: fauna is the oldest of the -^lura Bluff fauiias. Tnether the slightl. - -0 - er Oalc Orove and Shoeal RiYer molluscs indicate a chanrfe from the ;..u"btropio&l conditions of the Ohlpola will be >nown when the present ctii'!':- -:" those feax-e.-. l.. eompletpd. ^v, t>p no n i. -"'er.' tion of the correlation of the -'jovvden fatu:a the character ox the Shoal Hiver faizna, v.feiGh. Is now virtu.all, ;>:noTi7n, is of pri' ary i-"Oortance_. On the vvhole it ceems that the 2ov/den fc una i3 dictinct- Ij- i^ounger than the Ghipola and it nay "be tentativel, ■>;£*: It * •: i^^S Burdigalian, fon -h i :■ ^ Tower Hl^^o^ic, ^c;^, '-n the sense of most American Btrciti5:rapuers. i'he xjurdigalian is cng- gf.oted not 30 much beca-ace the' f anna recGiables the Btirdigalian raoll --'"^c-'-' ''•'^ "^i^ro'-'e, '^' ''O expresii its post--. 1 .'.zn a,p;e. It will be ueen tiiat thib view is in conformity- Vvlth the opinion of Euro oe an paleontolog-ists who hcve been iiiterected in West Indian Tertiar; , '^--^ -'-v.. --oncl-aoion "•■-'•■ "■'-en '-e^'^ocd bj^ a riifferent method of attack, bixioe an attempt ha.-.; been made to correlate with the Imerican section. The present work of Dr. Yau/'-han and hi;: -ciate .'onnectlon ^^ -f^in ':>,p rrr.o'' laical in- vestigation of some of the iior fchern I.e:--ser ..-infcilles, of ■.-hich orelimin^rj'- notic; -^e ''■:)e'n -)iih~i;;hed (1), ^tely es- (1). Taughan, U. i/., O&rne^ia Iiist. .Vashiac'ton, Vec.r 3ook, no. 15, pp. 558-560, 1914; Year *3ook no. 14, o .. ^ ^_'^7.^^, 1915; Joiir". Yfashinq'ton Acad. Sei., vol. 5, no. ' , ;. 3-490, 1915. - 41 - ta"bli;jixecl tv/o Upper ' oexie Antillean horizo, cor- relatec v.lth ^reoinion v/ith the ^loriclian cectior.. ~ eii top oil wiiici- ' loui'; V. .Lvalt-'iib iio tlie Jliipola. 11" Id be added that the present correlatioii c _ -Bowden fartns e Oligoeene xavuia of Florida, the Shoal lUver. - 42 - Order P I? I 0 IT 0 D E 3 M A 3 E A . Superfamily IIUOULACEA Ti'araily ITuculidae Genus NUOUIA lamarofe Subcrenus Fucula s. s. NUOULA MORAITTMA n. sp. Description.- Shell small, subtrigonal, moderately inequi- lateral, moderately inflated; anterior margin gently convex, rounding rapidly into the symmetrically arcuate base; posterior margin shorter, m th a steeper slope and slichtly more convex curve, insinuated below by the impingment of the boundary of the impressed area behind the umbo; umbones moderately prominent and opisthogyra-e, placed behind the me-^ian yertical;, area behind the umbo definitely impressed, relatively large, cordate; exter- nal sculpture of coarse and strong concentric rugae and less con- spicuous and finer radials which on ad;ilt shells fail to over- ride the rugae; the scalptiire of the posterior irrpressed area sim- ilar to that of the remainder of the shell, but weaker; chondro- phore narrow, oblique; hinge heavy for the si-'e of the shell, ant- erior series consisting of about ten teeth, slightly arcuate; post- erior series shorter, straight, including about six teeth; inner marp-in of the vslve finely crenulated. Mrensions.- Length, 4.8 mm.; alt. 4 ::m. ; semi-diam. .9 mm. - 43 - Remarks . - This small and delicately sculptured siDecies is represented by a number of valves. The eharacteristio features are the weakly, but obviously, impressed pseudo-limule, the rel- atively strong sculpture and the moderately inequilateral o.tline. F. tenuisculpta ":abb (1), a Santo Domingo Oligooene form, is more (1). Trans. Am. Philos. Soc, new ser. , vol. 15, p. SoS, 1875. elongated and has weaker and finer concent rio sculpture and strong- er radial striations. Guppy has described two species, IT. vieta (2) and IT. bacca^:a (5) from the Pliocene of iTatura, '""rinidad; vieta is (2). Proc. 3ci. Assoc. Trinidad for 1867, p. 174; Geol. Kag., Decade 2. vol. 1, p. 443 (check list); vl. 18, fig. 8, 1874. Dall , (Trans. V.'agner ?ree Inst. Sci., Philadelphia, vol. 3, pt. 4, p. 577, 1898) has placed this st)ecies together v7ith tenuisculpta Gabb in synonymy v;ith crenulata Hinds, but the two fossil species, at least, are -'istinct from each other. smaller, higher, more oblique, more inflated and is without the posterior impressed area, v.^.ile b ace at a is larger, more oblique, (3). Idem, 1857, p. 174; idem, 1874, p. 443, pi. 18, fig. 7. more inflated and has lower ambones, no posterior area, finer sculpture and more persistent radial striae. - A/1 _ Occurrence.- lower L'iocene : Bowden beds, Bowden, Jamaica, - 45 - Section Plasiasarepta n. sect. I I Et^moloff^.- TT^i n(rt-fl(^oL>^-to approach; Sarepta, a genus of pelecyoods,! Shell of me diiim size, well inflated, transversely subellipti- cal in outline; inequilateral; innbones low, opisthop-yrate ; areas hefore and behind the beak not differentiated; external sculpture consisting of numerous, regular concentric rugae; teeth forning the hinge relatively small, in two series, a longer anterior and a shorter, heavier posterior, separated by the ehondrophore ; lig- ament entirely internal, seatel on a relatively lar°-e, deep-set, oblique ehondrophore which is placed immediately before the umbo; internal margin of valve smooth; pallial line not known. Type . - IT. hilli n. sp . In ST-rae respects this section is rather far remove:", from the typical IJuculas, especially with regard to outline and sculpture. ATDparently it ap^jroaches the genus Sarepta A. Adams, the tyne of which, 3_. speciosa is a recent Japanese form; the members of that genus are, however, roundei-ovate, and therefore equilateral or subequilateral, and have a narrow, elongated chondrophole, but at the same time there is at least a feeble development of an exteimal ; ligament, j^ the case of £. hilli n. sp. there is no recognizable trace of an external ligament, the ligament being confined to the interior of the shell where it is situated on a i^rominent, oblique- : ly directed ehondrophore. Externally the shell somewhat resembles - 46 - certain regularly subovate or subell iptical forms of the genus Mallet la, as the recent ".Vest Indian K. Smithii Dall or I^. oytherea Dall, but that genus is charac'-erized by the entirely external posi- tion of the licrament . - 47 - KUOUIA (PLA3IA3AREPTA) HILII n. sp. Desoriptlon,- Shell of raediuin size, thin, polished, decidedly inflated, ineq^ii lateral; outline transversely- suheiliptioal, roimd- e ". posteriorly, produced and rounded anteriorly, ventral niargin gently arcuate; umhones low, opisthoeryrate ; external surface sculp- tured with well-defined, numerous, regular concentric rugae, which hecone cro7/ded and less prominent on the dorsal half of the shell, the umbo being almost smooth; chondrophore relatively large, elong- ated, suhtri angular, its axis oblique and c -rved , deep^-y set, plac- ed immediately in front of the umbo; hinge-tteth short, in two series, decide'^ly discrepant in length; the anterior series longer, moderately curved, including fifteen or sixteen teeth progressively reduced in size t ov/ard the chondrophore and continuing almost to the tip of the umbo, the last few treth being placed along the upper anterior margin of the chondrophore; posterior series short, straight or slightly concave, numbering five or six teeth of virtually the same size, the series ceasing abruptly at the chondro- phore; inner margin of the valve smooth; internal surface of the shell polished; muscle scars and pallial line obscure. Dir.: ens ions .- Length, 8.9 mm.; alt., 6.9 mm.; semidiar.., 1.9 mm, Remarks.- The subelliptical o;rf;line, inconspicuous urabones, well defined and regular concentric rugae of this species, which is represented by a number of valves, prod ice a facies which is 46 quite -unmistakable. It is, in fact, unique amor^g- the Tertiary and Recent Tuoulas of the Aatillean region and is oo ioiisly so different from the majority of ITuGulas that it might well be referred to a distinct category of more than sectional value. No forms german are Icnov-Ti from the American Tertiaries. Of the re::ent Antillean sr>ecies N. oymella Dall (l) has regizlar concentric sculpture and smooth internal margins, hut in other features the shell is more typically nuculiform, being less inequilateral and smaller than hilli, roimded- trigonal in outline and having the hinge more sym- metri cal. This st^ecies is nan.ed in honor of Mr. Robert T. Hill, Y.^hose reconnaiscance of Jamaica was an important step in the elucidation of the stratigraphic succession of that island. Occu-'renoe.- Lower Miocene: Bowden beds, Bowden, Jamaica. (1). Bull. Mus . Gompt. Zool., Harvard, vol. 12, pp. 246-247, 1886; Proc. U.' 3. ''at.Mus., vol. 12, v. 258, pi. 13, fig. 1, 1389. Family leiidae Subfamily Leilnae Genus ISDA Schumacher Section Jupiteria Bellardi LEDA ( JUPITERIA) PEITEILA Ball leda acuta Gahb, 1873, Trans. Am. Philos. Soc, new ser., vol. 15, p. 255, (ex parte). ]?ot I. acuta Oonrad, 1G?2. leda peltella Ball, 1898, Trans. V/agner Free Inst. Sci., Philadelphia vol. Z': pt. 4, p. 579 (name only), pi. ?2, fi^.' 5. Description.- "Shell elongate, convex, beaks central; anterior end rounded, base broadly convex; posterior end acute, hinge slight- ly concave from the beaks to the posterior end. Surface marked by regular rounded concentric ribs. Length .^5 inch." (Gabb, 1873) Type locality.- Santo Domingo. Shell of medium size, plump, decidedly high, slightly inequilat- eral; anterior and posterior ends alm.ost equally produced, the ant- erior margin rounded and the posterior forming a rostrnjn, typical- ly short, blnnt and very slightly recurved; ventral margin decid- edly arcuate; umbones low, subcentral in position; lunule narrow but distinct, bearing relatively coarse transverse elevations not continuous with the concentric rugae; escutcheon large, bounded by a well-marked carina; a faint sulcus visually nresent adjacent to the rostral carina, anteriorlj? a second sulcus may be present; oC - external sculpture of regular, closely-set concentric rugae, equ- ally develoioed throughout and extending §^3?0ss the rostral carina and escutcheon, but ceasing at the edge of the narrow lunule; teeth strong, with about twenty before and fifteen behind the small ch^n- drophore. Pi ensions.- length 8.8 mm.; alt. 5.8 nira. ; semidiam. 2.4 ram. Reinarlrs . - The typical forms of this soecies- the most pro- lific of the Ledas- are characterized by their unusual, almost rotund, shape, v/hich, together with the features of the limule and escutcheon, permits such forms to be readily recognized. It is not surprising to fine raarkec! variability in a f?roup which is so well represented. The most r-arked variation is toward a more elongate form and the end products are notably different from the average form. A different appearance is presented by cer- tain forms which are high, but have the posterior carin sharper than usual, the escutcheon broader and the posterior and anter- ior sulci more definitely developed. The presence of an area in front of the beaks wrich differs in sculpture from the remainder of the shell is employed as the criterior In assigning these two antipodal tyoes to this species. The sculpture is, however, fair- ly constant, although on a few forms the rugae are coarser than on typical individuals. The posterior sulcus is seldom conspiciious , in fact, very few individuals display it to such a degree as the one figured by Dall, and an anterior sulcus is but rsrely developed. - 51 - Among Gabb's acuta are some forms which are larger than pel tell a. more elongated and attenuated posteriorly and have a more concave posterior dorsal margin and more convex base; they probably should be seoarated from the other forms which resemble the Bowden peltella. Occurrence.- Oligocene, Santo Domingo. (Gabb, 1875) loi^.'er Miocene: Bowden beds, Bowden, Jamaica. (Ball, 1898) oi-l lEDA (JJPTTERIA) 03RATA Ball var. SUBVITHEAMORPKA n. var. ?Leda perlepida Guppy, 1867, ?roc. Soi . Assoc. Trinidad for 1867, p. 173, (ex parte) ?Leda perlepida "uppy, 1874, Ceol. Mag., Decade 2, vol. 1, p. 442 (cheok list), pi. 18, fif-, 9 (ex parte) Description.- Shell small, polished, transversely elongate, virtually equilateral, notahly convex; ventral margin broadly arc- uate, anterior margin abruptly rounde'^, posteriorly rostrate- the rostrum being of medium length, blurit and slis-htly recurved; ujn- bones tumid, strongly inc'Tved and opisthogyrate, placed approx- imately at the median horizontal; escutcheon poorly defined, bounded by a low rounde"* carina; area in front of beaks slightly impressed, but not forming a lunule ; external surface sculptured vrith fine ru?rae which are more sharply sculptured and crov/ded on the distal half of the shell and are continuous across the im- pressed areas both before and behind the bealrs; chondrophore rel- atively narrow and elongate; ab:»ut sixteen teeth in tVie anterior series and thirteen in the posterior; muscle scars relatively large pallial sinus obscure. Dimensions.- length, 5.8 mm.; alt., 3.4 mm.; semidiam., 1.3 mm. Remarks . - The members of this v/ell-re presented variety are sharply differentiated from the oo-existent ledas. The eloiHrate, equilateral form, polished surface and ventral orowdiix?: of the fine riiffae are characteristio features. Then compared with the more ahundant and highly variable pelt el la and indisrena the char- acters of the variety under discussion are constant. There is, however, a slight vsriation in shape, a few of the valves be ins- higher and therefore less elongate than the typical form; this difference in outline is fre-uently encountered among immature forms. The extreme elongated variants of peltella somewhat res- emble subvitreamorpha, but the tv^'o may sa readily be distinguish- ed since subvitreamorpha is less inequilateral, more convex, more bluntly rostrate and has more tumid and more decidedly opistho- gyrate umbones and distally crowded mgae; moreover, it does not have the lujaule or sharp posterior carina of cerata. In the rational l.luseum collection of Bowden material this form bears the naiae leda vitrea d'Orbigny, although that species does not appear in the 1903 check-list. ■ 1) A-jparently there is some confusion concerning I. vitrea d'Orbigny (2) and at the (1). Trans. Jagne r ^ree Inst. 3ci., Philadelphia, vol. 3, pt. 6, n. 1=^86. Several Ledas which do not appear in any of the Bowden collections at the writer's disposal are included in this list. (2). In de la Sagra, Hist., Phys., polit. et natur. riQ I'isle de Cuba, "oilusques, vol. 2, pp. 262-255, pi. 26, fisrs. 27-29, 1855 (drench ed.-) - 54 - present time it is necessary to rely on d'Or'oigny's figizres, despite the fact that occacsionally these figures have heen found. to he more artistic than accurate. .'/"hen compared v/ith the recent form which J3all{l ) has described as a variety of vitrea d'Orhigny's figures indicate that his vitrea is less elongate, more sharply rostrated, more broadly rormded anteriorly and has a more "Dromi- nent escutcheon and posterior carina, a slight posterior sulcation and a fairly well-defined transversely sculptured lunule. On 1-he whole these differences appear to be of an order sufficient to raise Ball's varietal name to Sjoeciiic rank. The Bov;den forms are very close to the recent cerata, but cerata of the same size are constantly different in having a less concave posterior dorsal margin, slightly more convex anterior margin, less convex base, less upturned rostrum and lower umbones. Apparently the recent form is quite variable, for a valve rhich is larger than any of the Bowden forms has a more concave post- erior dorsal margin than subvitreamornha. the base and rostrum are similar, but the umbo is proportionately lower. Until the recent species is better understood it seems advisable to consider the Bowden form' as a variety. Among Guppy's four cotypes of perle-oida. from the ^liocene (1). Bull. Mus, Oompt. Zool., Harvard, vol. 9, p. 126, 1881; idem, vol. 12, pp. 250-251, pi. 8, figs. 12, ISa, 1886. - 55 - of I'atura, Trinidad, are three small valves vfcioh oan soareely be distinguished from young', high Bovrden speciniens; the other, apparently adult, shell appears to he abnormal. ?urther explor- ation of the Trinidad locality may demonstrate the id-entity of the two forms, in which case Guppy's name would he prior. No ade- quate conception of perlepida can be obtained from Gupny's fig- ure. Dall (1) has pla-ed in synonymy with vitrea. L. milleri Gabb (2) from the Miocene of Sapote, Costa Hica, but that species is more like the large, elongated forms which Gabb included under his Santo Domingian I. acuta. (3) IIo definite statements can be made concerning Toula's Gatun "Lei a sp. (vielleicht eine neue Art, aff. leda vitrea var. oerata Dall u. Le^.a sublaevis Bell. )" (4) since the figure is poor and the discussion inadequate. It is. (1). Trans. 'Tae-ner Free Inst. Sci., Philadelphia, vol. 3, t)t. 4, p. 579, 1898. (2). JoxiT. Acad. Hat, 3ci, Philadelphia 2d ser. , vol. 8, p. 346, pi. 44, figs. 22, 22a, 1381. (As I'uoularia milleri) (3). See under discussion of I, peltella. (4). Jarhb. K.-k. e-eol. Reiehsans'alt, vol. 58, p. 719, lol. 27, fig. 2, 1908. however, larger and more inequilateral than sub v i t r e amo rph s. and. in all probability is distinct. rjo O?ourrerxce.- lower Iliocene: Bowden iDeds, Bor.den, Jamaica. ? Pliocene (?) - Matura, Trinidad (Gnppy 1867, 1874) - 57 - Section leda s. s. lEDA (lEM) I^DIGSIIA Dall. Le6a bisiiloata Guppy, 1867, Geol. Ivla:^., Decade 1, vol. 4, pp. 500-501, fig. 2. Leda bisnloata Ouppy, 1374, Geol. Hag. Decade 2, vol. 1, p. 442 (check list) Leda bisulcata Guppy. 188S, Proo. Soi. Assoc. Trinidad, p. 17?, pi. 7, fig. 7. I'lot L. bisnlcata reek and "■a.yden, 1861. Leda indigena Dall, 1898, Trans. V/agne r Free Inst. Sci., Phila- delphia, vol. 3, pt. 4, p. 579 (nanie only). Description.- "Shell ovately trigonal, \vith numerous concen- tric ribs narrower than their interstices; 'Alth a somewhat sinuous elevated ridge running from the umbo to the pointed rostrum behind; rounded anteriorly with a roiind groove running from the umbo to the ventral margin near the anterior angle. IJmbones close; oost- erior dorsal area flat, sloping, striate continuously with the ribs of the disc; no very distinct anterior area. Teeth very prominent." (Guppy, 18 67) Type locality.- Jamaica. Shell small, moderately inequilateral; posterior dorral margin slightly e: cavated; rounded anteriorly, sharply rostrate posteriorly, the rostrum being slightly recurved; ventral margin gently arcuate; umhones lov;, tumid, proxi-ate, slie-htly opistho- gyrate ; luniile not differentiated, represents"! hy a sliphtly de- pressed narrow zone; escutcheon sharply differentiated, broad, extending to the tip of the rostrum, bounded by a stron?, sharp carina, which becomes slightly broader and flat dis tally, the exterior eds-e being sharp throughout while the edge facing the escutcheon is lower and less sharp; i::mediately anterior to the .- rostral carina is a shallov/ sulcus v.hich is best defined in the umbonal region and scarcely affects the ventral mare-in; anterior- ly a shallow, but sharply li alter!, sulcus runs from the umbo to the ventral margin, the outline of which it rarely affects; external siirface sculptured with closely-set, regular, continuous concen- tric rugae, equally strong throughout find persisting across the rostral carina- and escutcheon; teeth strong, about fifteen behind and sixteen before the deeply-set, small triangular chondrophore. Dimensions.- Length, 6.5 mm.; alt. 3,8 nun.; semidiam. 1.5 mm. Remarks.- Although the forms referrable to this species are quite variable, they may usually be recognized by the pointed, slightly recurved rostrum, the sharp posterior carina and the broad, long escutcheon v/hich is conspicuously sculptured by the persistent concentric rue-ae. Variations occur iorinci pally with regard to shape and the size and spacing of the concentric rugae. The tynical indigene is rather elongate:^-, but some forms tend to - oO - approach peltella o^ "being higher; such forns are distinguished from even the unusuallj" strongly carinated and sulcated variants of the peltella group "by the more decided emphasizing of the carina and accompanying sulcus, the more conspicuous development of an ant- erior sulcus, the presence of 3 more attenuated rostrum and the absence of a lunule. On the other hand, the elongated variants of peltella also apioroacli indifcna,- in this case the less sharply rostrated and sulcated forms of indigena^ "but such mem"bers of the peltella group may invsria'bly "be recognized "by their weaJcer carina, "blunter rostrum and differentiated lunule. The young of indigene are proportionately higher than adults. On either side of the anterior sulcation a few faint radiating lines, su"bparallel to the sulcation, are occasionally present in the interspaces "between the r-ugae. This species is a conspicuous element among the Ledas of the fauna, "being surpassed numerically only "be peltella. I. indigena is very closely related to I_. acvita (Conrad) (1) which ranges from the Upper Oligocene Ghipola and Oak Grove "beds of Florida to the Recent and also has a vv'ide R-eo-raphical ran^e. The 3owden species is, hov/ever, in general terras smaller, less (1). Am. Mar. Conch., p. 52, pi. 6, fier. 1, 1832. :^or s.; nonymy see Dall, Trans. V/agne r ?ree Inst. Sci., Philadelphia, vol. 3, pt. 4, pp. 592-595, 1898. - 60 - elongate, and has a more recurved rostrum and a more constantly fine coneentrio sculpture than acuta, as that s-oecies is accepted; in addition the rostral carina is sharper and the sulci more pro- nounced than in the case of most a out a. Hone of the forms at hand have a sculpture as coarse as that which is commonly seen in any collection of acuta. The Bowden species varies -orincipallj with regard to shape; while the most notable variation of acuta con- cerns the sculpture. The tendency of indlp-ena toward a less elongate, higher shape is very noticeable and therein lies, perhaps, the prirjc ipal distinction between the two. I. do dona Pall (1) , of the Chipola marl of Florida, belongs to the same general group. It may be distinguished by its very coarse concentric rugae and also by its almost smooth escutcheon. A species from the Oak Grove send of Florida, I. troohilia Dall (2) is also closely related, but is recognized b^ the wide spaces be- tween the often discontinuous and irregular rugae and by the ab- sence of rugae on the rostral csrina. The Eocene (V/ilcox) I. rob- ust a Aldrieh iZ) has coarse concentric sculpture v/aich is evenly (1). Trans. V/agner Free Inst. Sci., Philadel-ohia, vol. 3, pt. 4. pp. 589-590, pi. S2, fig. 6, 1898. (2). Idem, p. 590, pi. 32, figs. 4, 12, 1898. (3). Bull. Amer. Pal., vol. 1, no. 2, p. 17, nl. 5, fiers. 1, la, l§95. - 61 - spaced only on the umbo and is almost obsolete in the region anter- ior to the anterior sulcation; in addition the chondronhore is placed well tuider the tmiho so that it is almost concealed when the interior of the shell is viewed in norinal position. The "Leda "^f, acuta" v/hich Toala (l) described in his accoujit of the "Pliocene" fauna of Tehuantepec differ from both acuta and indjgena in having the posterior portion of the ventral margin less convey and a straight er and blux.ter ros'':r\im. It may be added that Guppy's figure of bi sulcata is poor and probably represents a yoimg, high indi^'ldual. (1). Jahrb. K.-k. geol. Reichsanstalt , vol. 61, p. 478, pi. fig. 6, 1911. Occurrence.- ipy.^er Miocene: Bowden be^ls, 3ov;derL, Jamaica (Guppy, 18 67, 1874; Dall, 1898). ^ — Ori - Section HelDeleda n. sect. Et7;molo°:y .- KeTDes,- "blimt; leda. Shell smsll, decidsf.ly inflate'-^, sub equilateral, bluntly rostrated; posterior carina subrounded; area behind the umbo flattened, but not impressed; e:cternal sitrface sculptured with concentric lines usually obscure and irregularly developed; hinge- teeth in two subequal series, separated by a relatively wide tri- angular chondrophore; -ligament apparently entirely internal. Type .- I. bowdenisna n. sp. This section is proposed f^r the reception of two species and a variety - all new - which form a homogeneous group, sharp- ly differentiated from the associated Lerias. The group is char- acterizec! by its strongly inflate!, bluntly rostrated form. I. due r den i n. sp. , the shortest of the three forms constituting this section, externally bears some resemblance to certain rostrated forms of the genus Tindaria, such as T_. smirna Dall , a deep-water species from the &ulf of PanaLia, but aside from other considerations, Tindaria has an exteraal ligament. L. pontonia Dall, dredged near the Galapagos Islands, appears to belong to the group under con- sideration. Through forms v;hich are more sharply rostrated, less convex and more obviously sculptured Kebeleda grades into Jupi- teria. D.r- LEDA (H3BELSDA) BOWDIITIAI'IA n. sp. Peseription.- Shell small, decidedly convex, transvexSel;, elongate, outline sub-trigonal posteriorly rostrete, subequilat- eral, dorsal marp-ins with steep slopes, the anterior being con- vex anfl the posterior concave; produced and abruptly roixnded anteriorly; posterior margin forming a short blunt rostrum; broadly and symmetrically arcuate vent rally; umbones apr^roximate- ly central in position, high, very tumid, strongly incurved and opisthogyrate ; area behind the umbo flattened; posterior carina low, broad and very feeble distally; external sculpture of irreg- ularly spaced, poorly developed, fine impressed lines, obsolete on the umbones and in the area within the posterior carina, and coinciding v;ith the irregularly spaced lines of growth in the distal half of the shell; chondrophore triangular, relatively broad; teeth in two series, with about nineteen in the slightly convex axiterior series and about thirteen in the co..cave poster- ior series, the median teeth being small and obscure; muscle scars faint, rela^^ively large; pallial line obscure. Di: ens ions,- length, 6.2 mm.; alt., 4,5 mm.; semidiam., 1,9 mm. Remarks.- i'his species, the t;. ne of the section, is described from several valves v;hich display constant characters. - 64 - The Galapagos form mentioned above, I. pontonia Dall (1) is larger and has a more excavated postero-dorsal margin and more (1). Proc. J. S. Kat. Mus., vol. 12, p. 257, pi. 17), fiPS. 5, 5h, 1889. oonve:- base. Ocourrence . - laver Iliocene : Bov/den beds, Bowden, Jamaica, - 65 - LEDA (HEBELSM) BOvrDSTTIAIIA var. SUBTmilDA n. Ysr, Description,- Shell resemlDling the typical bowdeniana. hut more elongate, slightly less convex; umhones lower and less tumid; ventral raarprin less curved; sculpture coarser and more irregular; chondrophore hroader; hinge with about sixteen teeth in each series, the anterior series more convex and the posterior less concave than in the tj-pieal bowdeniana. Di.nensions.- length, 6.5 mm.; alt., 4 mm.; semidiam. , 1,7 nm. Remarks.- A number of valves are inc^'uded ujider this var- iety. '.Then coranared vrith bowdeniana they show the above diff- erences, which, though slight, involve many characers and are constant. Since the variety is more elongate and has lower umbones, it follows that the slope of the dorssl margins is less steep and the postero-dorsal margin less excavated. A poorly preserved shell which is higher than the typical bowdeniana and has a shorter rostrum and obscure concentric sculp- ture which is obsolete on the posterior half of the shell, prob- ably indicates a tendency to variation in a direction antipodal to subtximida. Occurrence.- lov/er lliocene : Boxvden beds. Bow den, Jamaica. - 66 - LEDA (HE^EIEDA) DUEKDMI n. sp. Desoription.- ^hell small, polishet^, to imderl -til angular with a short posterior rostrum, decidedly convex, suh equilateral ; posterior dorsal margin slightly concave; bluntly rounded anter- iorly; ventral margin asymmetrically arcuate, being slirrhtly more convex posteriorly; umbones ^igh, tumid, strongly opisthogyrate ; area behind the umbo distinctly flattened; rostral carina lov/, broad, but strong *^J^oughout ; e:-ternal sirrface s c lil ot ure d with fine, evenly spaced, concentric lines except on top of the umbones and in the area bounded by the rostrsl carina- the sculpture at times obsolete on the posterior half or entire surface of the shell; chondrophore large, triangular, situated below and Just anterior to the tip of the umbo; teeth strong, the anterior series numbering- about thirteen and the posterior sixteen. Dimensions.- Length 4.9 mm.; alt., 5.4 mm.; semidiam. , ,9 mm. Remarks.- I. duerdeni has a facies totally different from bowdeniana; it is smaller, higher, and has a shorter, but more acute, rostrum, stroi^ger ventral carina, more regular and more delicate external sculpture, larger chondrophore and heavier hinge. In outline it stands in decided contrast with the average leda and without the testimony of the ligament wo ;ld probably be placed - 67 - among- the rostrated Tindarias, for which Yerril and Bi.ish (1) pro- posed the subgenus !I?lndarlopsis . (1). Am. Jour. Soi . , 4-th ser. , vol. ?^ p. 59, 1897. The na-:ie is given in recognition of the services of Dr. James E. Duerden, now of Rhodes University Oolle^^e, (Jrahamstown, South Africa, who while Ourator of the Lluseitm at Kingston, Jam- aica, collecte' the Bowden material which constitutes the Duer- den Collection of the Johns Hopkins University. Occurrence.- Lower Miocene: Bowden beds, Bowden Ja-naica. lEDA (?) 3LARA Quppy. leda olara Gupp:^ , 1874, Oeol. Mag., Decade 2, vol. 1, p. 442, (oheok list) pi. 17, figs. 1, la. leda Clara Gupoy, 1875, Geol. Mag., Decade 2, vol. 2, p. 42. Leda clara Guiopy. 1^382, Proc. Sci. Assoc. Trinidad, p. 172, pi. '?', fig. 4. Description.- "Subelliptical, lanceolate, nearly equilater~ al, somewhat but not extremely rostrted. Disk smooth, shining; valves with a few fine close regular concentric riblets r)ercepti- ble near the anterior ai:!o:le, vvhere an indistinct sulcus runs up- wards towards the umbo. IIo distinct escutcheon, Lunule narrow, indistinctly defined. Urabones prominent. Ventral mars-in slight- ly angulated at about a third of its length from the posterior point, *ere an obscure carina ruj.s to the m.arpln from the umbo. Length 12 mill., height 6, thickness about 4 ram." (Gupoy 1875) Type locality.- Jamaica. Shell large, heavy, moderately convex, subequilateral; ant- erior dorsal margin conve", posterior dorsal margin excavated; abruptly rounded anteriorly; posterior margin bluntly rostrate above and obliquely truncated below, the slope of the trimcat- ion abruptly joining the direct, me-^.ian portion of the ventral margin; umbones low, a-rproximately centrcl in position, strongly - 69 - opisthogyrate ; lumiile not differentiated, represented tiy a very narrow, slightly flattened area; area iDehind the -umho wider, flattened; rostral carina siti^ated near the dorsal ma.rgin, low, relatively hroad, subrounded; distal third of the shell hearing a very shallow sialcus iicnediateiy anterior to the rostral ray, the sulcus very slightly emarginating the trmicated posterior margin; external surface sculptured with fin, ir.pressed lines, feebly developed on the umbones and accentuatec' by irregularly spaced incrementals in the distal half of the shell; chondro- phore large; teeth strong, becoming finer toward the p-?int of divergence, the anterior series numbering about nineteen and the posterior series fifteen; muscle scars and i^allial siniis obscure. Dimensions .- Length, l"^. 5 mm.; alt., 7.5 mm.; semidiam. , Remarks.- This species is conspicuous as being easily the largest of the Bovden. Ledidae. Young shells display onl:; a feeble posterior truncation below the blutit rostrum, but on mature individuals this feature is especially prominent. Since the pallial sinus is obsc:;re the proner position of this form is doubt- ful; the shape, character of the external sciilpture and absence of a well-defined lunule and sharp rostral carina suggest that it may find its oroper place in the section Portlandiea of the genus Yoldia- a section v/hich has been considered of generic v lue, intermediate between Leda and Yoldia. - 70 - OoGurrenoe.- lower I'iooene: 3c";7-den "beds, Bowden, Jamaica. (C-uppy 1874, 1375; Dall , 1903 (1) ). (1). This date refers to the check-list on pp. 15£'2-1568 of ypT_ "^^ pt. 6 of the Wap-ner Institute papers. References will be givento this list only when the species is not designated as a menher of the Bowden faima in the te--;t. - 71 _ GemTS YOIDIA MSller. YOLDIA 0VALI3 Gabb. Yoiaia ovalls O-abb, 1373, Trans. Am. Philos. Soc, new ser., vol. 15, -op. 255-256. Description.- "Shell small, oorapressed, s\ib-elliptioal; beaks slightly in advance of the middle; hinge line sloping rrent- ly, base and ends rour.de-^; surface smooth or bearing a few faint impressed concentric lines on the anterior part near the base. Length .35 inch, width .15 inch." (Jabb, 1873) Ty-oe locality.- Santo Domingo. Shell of medium size, thin, polished, transversely sube:'lip- tical, moderately conve?:, decidedly compressed posteriorly; ant- erior dorsal margin shorter and more oblique than the posterior, the distal ends of both abruptly Joining the lateral marp-ins; anterior lateral margin roimded; upper portion of the posterior lateral margin almost at right angles to the dorsal niargin, low- er portion rounding evenly into the gently and symmetrically &ro\m.te ventral margin; umbones very Idw, situated anterior to the median hori.-:ontal ; behind the ambo lies a very narrov/, slightly ir.presc- ed area, sc;,LLptured v,lth fine lines and containing in its proximal half a raised line t)arallel to rnd scarcely senarsted from the outer edge of the area; anterior to the nraho is a similar, but shorter area; external soul-pture of ver;; fine, inconspicuous, impressed lines, obsolete in the umbonal and posterior regions and at ti^-es over the entire shell; ehondroTihore relativelj^ large; teeth fine, the two series diverging at a very obtuse angle; about eighteen teeth in the anterior and twenty in the posterior series; anterior teeth larger, in both series the size reS.uced gradually toward the point of divergence; muscle scars obscure; pallia! line sharply, b-.t not dee-oly, sinuated. Dimensions.- length, 10.7 nm. ; alt,, G mm. ; semidiam. , 1.8 mm. Remarirs . - Jhe feebly impressed areas before and behind the umbones are very narrow and inconspicuous. In the case of young forms it may be better to describe the shell as having before and behind the umbones a very narrow and shallow sulcus which impinges on the dorsal mari^-iriS at approximately the dis^'al extremities of ^he hinge, since on such forms the ridp-e just inside what is des- cribee^ as the im.pressed areas in the adult is prominent enough to caiise such an aopearance. The anterior and posterior marg-ins are sir:ilsrly rounded, but the curve of the posterior mar^-in is more complete since the posterior dorsal mars-in is less oblique than the anterior. iEhe single Santo Domingian specimen is slightly more elong- ated than the Bowden forms and has very feeble concentric sculp- I c - ture which is developed only near the antero-ventral margin. Y. solenoides Ball (l), a recent species from the Gulf of Ke:ico, (1). 3nll. ITus. Oompt. Zool., Harvard, vol. 9, p. 127, 1381; idem, vol. 12, p. 248, r)l. 9, figs. 2, 2a, 1886. has the same general facies, hut is more elongate, ttie length heing slightly more than twice the altit^i'^.e, the p^Jo-ne of the anterior dorsal margin is less steep, the posterior dorsal ma.rgin Joins the lateral mar?. 445 (Check list). Area oooidontalis Philippi, Guppy, 1876, '^'uart. Jour. Geol. Soc. London, vol. 52, p. 551. Area ocoidentalis PhlliiDji. Dall, 1898, Trans. V/agner Free Inst. Sei., Philadelphia, vol. 5, pt. 4, p. 620. Aroa oeoi dent alls PhilipiDx, Dall ?c Simpson, 1901, Bull. U. S. Gor.an., vol. "0, pt. 1, pp. 459-460. De so ri rt ion. 4 "A. testa elongato-obloma, suTDcuandrangiila; latere antioo breviusiJloo, ang-alo fere rec'-o terrainato; postice emar?:-inato ; carina obt-sa ab apice deo^irrent ei ; costis regxilaribxis, prominentibus, interstitia longitudinal iter striata subaequanti- bus ; ^rae'ianis parum minorib s; area dorsali me^'^iocri; li?; ventral half of the shell with a slight median depression; external surface sculptured with num- erous fine radial ribs separated by narrow interspaces except on the posterior slope where the ribs a:.'e wider and the interspaces • of about the same width; the ribs occasionally dichotomous : con- centric sculpture developed throughout by nodulations on the ribs; cardinal area. narrow, excavated, widening slightly in front of the umbo, transversely striated; hinge with a continuous series of teeth, the Iteeth oblique at the extremities, small and vertical m me'Ually; inner niar~in of the volve without definite crenulations. Di'-ensions.- I.'ax. length, ii mm.; max. alt. 5.8 r;im. ; semidiam. 1,8 mm. ; length of hinge, 4,5 mm. This species is described from a single valve. It Is immed- iately distinguished from A. reticulata by its less elongate form, more rounded posterior ridge and decidedly finer scijlpture. The Oaloosahatchie A. millifila Dall(l) is larger, proportionately (1). Trans, "vag-ner Free Inst. Sci., Philadelphia, vol. ?, ot. 6. p/ 1629, pi. 5 6, figs. 21, 24, 1902. - 99 - higher and has a straighter base, fewer and le:-:s conspioao-asly nodulated radials and wider interspaces. Ooo-arre'.i3e .- lower Miocene: BoT/den "beds, ^ovjden, Janiaica. -100- Section Oalloaroa Gray. ARGA (OALIOAHGA) GAKDIM Gmelin. Area panel Ida Eel"blin.?i Jhemnitz, 1874, '-^oneh. Gab., vol. 7, p. 195, pi. 55, fip-. 542. Aroa oandida Gmelin, 1791, Syst. Nat., vol. 6, t). 3311. Area Jamaicensis Gmelin, 1791, idem, p. 3312. Area Eelblinp-ii Britgui^re. 1797, Ency. Meth. , p. 195. Aroa Candida Ghenmitz, d'Orbigny, 1845, in de la Sagra, Hist. fis., polit. :: natur. de la Isla de Guba, '.'olluscos, p. , (Spanish ed. ) ; 1853, idem, vol. 2, pp. 319-320, (French ed . ) , Barbatia Tjonaoz.y.i Gabb, 1873, Trans. Am. Philos. Soe., new ser., vol. 15, pp. 254-255. Aroa imbrioata Gabb, 1881, Joixr. Acad. ITat. Soi., Philadelphia, 2nd se ■., vol. 8, p. 378, (as of Brup-ui^re) ex oarte .(?^^ ^xd.J Barbatia (Galloarca) Candida Gmelin. Dall, 1898, Trans, v/agner Fr: e Inst. Sci., Philadelphia, vol. 3, pt. 4, pp. 626-627. Aroa oandida Gmelin, Dall & Simpson, 1901, Bull. U. S, ?ish Gomra. , vol. 20, pt. 1, 0. 460. - 101 - Description.- "A. testa -pellucida rhorn'oidali anterius oro- ducta posterius truncata decussatim striata; natibus reraotis, mar- p-ine posterius hiante ; hiatu ovato ciliato." (Gmelin, 1791) The Bov/den s pecimens are of medium size, sub trapezoidal in outline, somev;hat compressed; asymmetri callj rounded anteriorly, posterior end trxincated above, acutely produced below; posterior rid?-e lovr and broad; umbones low, situated at about the anterior fourth of the length; external scalpture of numerous, sharply cat closely spaced radial ribs of different width, being narrowest in the central portion of the shell; the ribs occasionally '^.icho- tomous or the interspaces with s econdary , intercalate"! radials; ribs nodulated at irregular intervals, the ribs beirjf widest and strongest, the intercostal S"o£ces widest and the nodules most prominent on and behind the posterior rid re; cardinal area of med- ium width, crossed by several diverging lig anient g:rooves; teeth in an ^interrupted scries; but the me'ian teeth very short; inner margins with irregular, inconsoicuous crenulations. Si'. ens ions.- length, 26.5 mm.; alt., 13 mm.; semidiam. , 5.8 mm.; length of hinge, 15 mm. Remarkfe .^ ITum.erically this species is well represented, but the majority of the specimens are much smaller than the one meas- ured. Some irre'ularity in shape and nroportions is noticeable. A, Candida may be recognized by its somewhat compressed valves and - lOp - beaded radial ribs, whieh are especially prominent on the posterior slope. The Santo Doningian form v;hich Ga'-^b described as Barbatia bonaezyi apparently is candiga. although one of his two types has sculpture that is finer than usual" and both have a less sharp posterior rid e and therefore a less excavated posterior slope than the average candi da . As mentioned above in "tiie discussion of A. umbonata, Gabb's Josta Pdoan Pliocene material under the name of inforicata includes some forms which should be referred to candi'-la. Occurrence.- Oligocene.- Chipolaraarl, Florida (Dall, 1898) Santo -Domingo (Gabb, 1875). lo\-er lliocene: " Bo?/den becls, Bowden, Jamaica (Dall, 1898). Pliocene.- limon, Oosta Hica (Gabb, 1881). Trinidad (Ball, 1898). Pleistocene.- The Antilles generally (Dall, 1898). Recent.- Katteras to southern Brazil in less than 50 fathoms. _ 1 ■^' -1 ARGA (OALIOAHGA) liKDOIvIENA n. sp. Description.- Shell small, elongated, subtrapez^idal, deci- derlly inflated; dorsal and ventral rnar'-ins subparallel, the ventral maro:in slightly arcuate, with a broad, feeble insinuation toward the posterior end; rounded anteriorly?; oosteriorly truncated, pro- duced below; umbones tumid, broad, situated at about the anterior third of the length; posterior ride:e rou.ided, but prominent; er- ten.al surface sculptm-ed with nxicierous radial ribs; the extreme anterior ribs separated by interspaces of virtuall: the sanie width, the succeedir]g ribs narrower, with the interspaces wider than the ribs and often bearing a fine secondary radial; toward the post- erior ride-e the ribs become wider and are separated by narrow im- pressed lines; on the posterior slope ribs few and broad, inter- spaces of about the same width; the radials beariiig obscure elev- ations along concentric lines, exoeot in the anterior portion of the shell where the concentric sculpture forms definite nodules; cardinal area morJerately wide, the posterior portion v/ith oblique- ly directed ligament grooves; hinge bearing about twenty-five teeth, the posterior ones notably oblique, the anterior less ob- lioue, the series uninterrupted i-edially; posterior and anterior inner mare:ins obscurely crenulated. Dimensions.- Max. length, 10 mm.; alt., 5.5 nmi. ; semidiam.., 2.5 mm.; length of hinge, 6.5 mm. - 104 Remarks.- A. endonena is represented hi one valve. Some of the characters sagg-est that its oroper nlace is in the section Acar, but the cardinal area is too wide. It differs from the young of A. c and i cJ a of the same size by being more elons'atecl, but less produced at the postero-ventral an,?-le , more inflated, with higher urabones and less conspicuously developed concentric sculpture. Ocourrence.- laver Iliocene: Bowd©n,beds, Bo-"den, Jamaica. -105- C^^" ARGA (GALIOAP.GA) DEIj:PI.DA n. sp. Pesoript ion.- ^hell small, moderately elongated, well inflat- ed; anterior end rounding rapidly into the iDase ; base almost straight very feebly emarginated ::Tedially, flexed upward at the posterior end; posterior mar~in produced below, obliquely truncated above; umbones conspicuous, broad; posterior ridge rounded; external sculpture consisting of mxmerous, fine radial ribs, ornaroented with conspicuous, delicately sculptured, square or slightly elongated, nodules throughout; as usual, anteriorly and posteriorly the ribs and interspaces wider, esoecially on the posterior slope; cardinal area ivide for the size of the shell, with obscxu-e trans- verse striations in the anterior and me-'ian regions and deeper ob- lique grooves postei'iorly ; hinge-teeth forming a continuoiis series, the teeth relatively heavy, normal in position; anterior and post- erior inner margins obscurely crenulated. Di'-:!ensions.- Llax. length, 6„5 nan.; alt. 4.2 mm.; semldiam., 1.8 mm.; length of hir^ge, 5 mm. Remarks.- The distingiushing feature of this species, which also is represented by only a Gin^^le valve, is the delicate, ret- iculated sculpture, by which feature alone it may be separated from the associated ^alloarcas. Because of the character of the sciapture it extemallj- iDears a closer resemblance to A. (Acar) pr ope rtua than to either can':^iia or endomena, but it differs from but it differs from that species by being more rep-Tilar in outline, more elongated, \vith a more delicate and more regular scidpture; more- over, there is the difference in the cardinal areas which places the two- perhaps ^ormaturall--- in different sections. Occurrence,- Lower Miocene : Bowden beds, Bowden, Jamaica. - 107 - AROA (OALLOAROA) IimSITATA n. sp. Description.- Shell of nerli-um size, higli, soraev/hat compress- ed, irregular; posteriorly a'cliquely truncated above and produc- ed below,'; irregularly rounded anteriorly; anterior portion of the ventral margin distorted by the long, -."ide by._;sal gape; urabones relatively low, broad, decidedly prosogyrate, at about the anter- ior third of the length; posterior ridp-e prominent, the region be- hind the ridge being excavated; external surface sculptured ?ath numerous, very narrow, irregular radial ribs, occasionally dicho- tomous and the interspaces occasionally bearing intercalated nar- rower secondary ribs; interspaces usually narrower than the ribs; the posterior slope sculptured witi: four ribs much coarser than the others; concentric sculpture of irregular growth lines and occas- ional raised lines, the two producing in certain oortions of the shell a feeble semi-reticulated sculpture; cardinal area relative- ly short and wide, conspicuously marked by six or seven concentric ligament grooves; hinge gently arched; anterior teeth irregi^lar, median teeth very short, almost obsolete, posterior teeth large, oblique; inner margin of the shell smooth or ";ith faint crenu- lations. Dimensions.- len-th, 31.5 mm.; alt. 22 mm.; semidiam. , 7.8 imn. ; length of hinge 12 mm. - 108 - Remarks.- Several valves are referred to this species, among them one which is not tj/pical since it is more produced posterior- ly and the cardinal margin is longer hehind the umbo. It is to he expected, however, that so irregular a form should be variable. A. inusitata may be recognized by its irregular, distortei shape, prominent byssal gape, e::cavated posterior slope and numer- ous, fine raf''ials. Several closely relate:! species have been des- cribed from various localities. A. irregrularis Dall (l), a Tampa silex and Jaloosahatchie form, is larger, with njnbonos that are (1). Trans. Was-ner I?ree Inst. 3ci., Philaf^elphia, vol. 3, pt. 4, pp. 623-624, pi. rs, f iff . 5, l',398. more posterior in position and coarser ribs. A. marylan^i?a Jon- rad (2), from the Oligocene of 'Florida and the KiOcene of i.'.sry- (2). Fos. i:ed. Ter. U. 3., p. 54, pi. 29, fi^. 1, 1040/ land, is larger, vath lov/er, less inflated umbones, a broad, low posterior ridge and an unexcavated posterior slope. The Tampa silex A. arcula Heilprin iz) is higher, more inflated, less regular (-?). Trans. Wagner ?ree Inst. 3oi., Philadelphia, vol. 1, p. 118, pi. 16, fig. 65, 1887. - 109 - in outline, with a less prominent posterior ridge and less excavated postericr slope. Occurrence.- Laver Miocene: 3ov/den "beds, Bowden, Jamaica. - 110 - Section Stenoarca n. sect. Et.ymolo~:y»- Treves - narrow; Area. Shell small, reticulately sculpt rel; imbones almost terminal, strongly proso^p-^^rate ; cardinal area narrow, irapreGsed, long, en- tirely or almost entirely opisthodetie; hinge-teeth in two series, the anterior, series short, thickened, more or less irregxilar, suh- tmibonal in position, the upper thickened margin ceasing abruptly behind the um.bo : posterior series longer and normal; the two ser- ies continuous or interrupted by the evanescence of the teeth at the anterior end of the posterior series. T;pe.- A. dentera n. sp. Three new species are referred to this section; of these dentera and suboandeida have an uninterrupted series of teeth, ^rf-th the anterior series notably thickened, while adult indivi- duals of modioleida usu.ally have a medial, vade e''"'entulons area. A. subgandei'ia has a very snail portion of the cardinal area before the umbones and in the case of the other tv/o species the cardinal area is entirely opisthodetie. From the above s-^atements it is evident that this section Is not sharply differentiate^!, but forms an intergrading series "lith other sections. The shape of dentera and §'^bcandeida suggests Jalloarca; in shape and in the oossess- ion of an interrupted dental series modioleida resembles Jalloarca and also Oucullaria, but the cardinal area does not extend in front - Ill - of the timbo. The cardinal area of A, suboandeiaa reaches in front of the Timho for a very short distance and in that ress^ect it hears a resemblance to some Oalloarcas, hut this soecies has the iJeculi- ar hinp-e of dent era, the tyrse of the section. The division of the teeth into a short, more or less irregular anterior series and l&nger, normal posterior series is somewhat similar to that found in the section Ar.p-ina of the suhg-enus Scanharca. hut the p-eneral facies precludes the possibility: of lin'iing a place for these forms among the Ars-inas. V/ith regard to hinge elements Stenoarca anpears to have much the oosition amoiog the Barhatias that Argina has among the Scapharcas. - 112 - ARGA (STEITOAHGA) DEE^^TSHA n. sp. Descripti on.- "^hell small, well inflated, decidr-:dlj inequi- lateral; almost vertically subtr-onoated anteriorly, produced and abruT^tlj roundeJ. posteriorly, "base gently arcuate; ujnbones full, broad, relatively prominent, strongly prosofyrate, placed almost at the anterior fifth of the length; posterior ridge broad and low; external sculpture of numerous, narrow, wealvly sculptured radial ribs of varying width, being widest posteriorly; concentric sculp- ture of irregularly spaced incremental lines and striae, slightly affecting the rc.dial ribs; cardinal area entirely opisthodetic, narrow, impressed, crosser" by three oblioue, nlightly raised lines; anterior series of teeth consisting of siz thickened, irregular teeth placed under the umbo, the thickened area ceasing abruptly behind the umbo and succeeded immedia'^ely by the pos-^erior series, the latter numbering twenty-three teeth ^^vhi'^h increase in size to- ward the distal end an? at "frhe en-'', of the series becone oblioue in position; inner mar-in of the valve smooth. Dimensions .- Length, 16 mm.; alt., 10.5 mm.; semidiam., 4.1 mm.; length of hinge, 9 mm. Remarks.- Only a single valve of this interesting form is present. The shape and soulcture suggest Oalloarca; the hinge Argina; but the cardinal area is unique. Occurrence.- lov/er Miocene: Bor/den beds, Bowden, Jamaica. - IIS - AR3A (STEITOAI^OA) SUBOAITDEIDA n. sp. Descrintion.- Shell small, -fcransverselv r-nibellim'Tloal. hioiher and more producefl posteriorly, slightly? inflated; posterior dorsal margin direct; rounded posteriorly, the curve of the upper portion being less convex; subtruncated anteriorly; ventral margin sloping gently downward toward the posterior end; umbones veyy low and flat, strongly prosogyrate, situated at about the anterior fifth of the length; posterior ridge low and very broad in the umbonal region, becoming obsolete toward the marjrin; external sur- face sculptured with numerous fine radial ribs, narrowest in the region below the ujnbo and widest posteriorly; the ribs separated by fine impressed lines except on the posterior slope where be- tween some of the ribs ^re interspaces as v.'ide as the ribs them- selves; concentric sculpture of regular, closely spaced concentric impressed lines, overriding the radials, thus producing a conspicu- ous reticulated sculpture and causing the ribs on the posterior slope to be nodixlated; cardinal area narrow, irapressed, almost en- tirely opisthodetic^ the very short portion in front of the umbo being widest; hinge as in A. dent era n. sp., but with five teeth in the anterior series and eighteen in the posterior; inner mar- s-in of the valve smooth. Dimensions.- length, 13 mm.; umbonal alt. 7.6 mm.; max. alt., 9.2 mm.; semidiam.. , 2.8 mm.; length of hinge, 7 ram. - 114 - Remarks.- This species, also representee' by a single valve, is closely related to A. dent era and undoubtedly belongs in the same genetic series. Differences between them involve factors of proportions, outline and sculpture, Aside from the difference in size, ^'hioh may be of no significance, subcandeida is lower, more compressed, especially posteriorly, the base has a decided slone; the umbo is lov/er, less inflated, more anterior in position; the sculpture sharper and. more obviously reticulated and the cardinal area extends in front of the umbo. Oc currence.- lower 1.1 ioceiie : Bowden beds, Bowden, Jamaica. - 115 - ARC A (STErOAIWA) MODIOLiilM n. 8 p. Desoription.- Shell small, thin, modioli form, somewhat oom- preascd, very inoquilatei\9.1, nroduoed and higher posteriorly; post- erior dorsal margin direct, long, anterior end rounded "below, sub- trimcate above; rounded posteriorly, the curve being lees convex above; ventral margin sloping downward posteriorly, slightly con- tracted medially; umbones very low, almost terminal; posterior rids-e not well defined distally, but high and broad in the umbonal region; sculoture of low radials, fine and separated by impressed lines in the region before the posterior ria^e, coarser, swollen and separated by as wit'^e or -rider interspaces behind the posterior rido-e; concentric sculpture of fine concentric impressed lines, as well as irree-ular incremental lines, producing a reticulated sculp- ture on unworn portion of the s ell; cardinal area very narrow, en- tirely opisthodetic, deeply impressed, with a low median ridge e:-?:- tending from the anterior end of the area to its ventral nerp-in at about the middle of the posterior series of teeth; anterior teeth numbering four to six, slightly oblique, more or less irregular, subumbonal in position, medial teeth very short and weak, or ob- solete, producing a long edentulous gep; about eight obliqne teeth at the distal end of the posterior series; inner margin of the valve smooth or minutely crenulateci. JiT.ensions.- length, 10 mm.; alt. in umbonal region, 4.1 mm.; alt. in posterior region, 6 mm.; semidiam., 1.9 mm. - 116 - Remarks.- The peouliar modiolus-like form of this small species at once distinguishes it from the co-existing Areas. It is representel "ny a number of valves; several bein.g slightly larg- er then the tyoe. The shape suggests Oalloarea anri the hincTe Oue- cularia, but the peculiarities of the cardinal area sonnect it most closely with the section Stenoarca. In the ca,;;e of this spe- cies the remarkable features of the carciinal area are even more strongly emphasised than in the other two species of the section. The cardinal area is entirely opisthodetic, exceedingly narrow and so deeply impressed as to be almost internal; indeed, if any portion of the ligament occupied the area below the meriian rid<^-e it may very well have been entirely internal. The teeth are t;;ni- cal of the section in that tbey are divided into two series, but the teeth in the middle of the hinse are very weak or entirely obsolete, leaving only the irregular anterior teeth and the obli- que, regular teeth at the distal end of the posterior series. All of the valves are more or less worn, so that the sculp- ture, which is nev- r prominent, is often faint. Several indivi- duals are less inflated throughout and more com-nressed in the posterior dorsal region than the typical form. A. suboandeida is larger, the posterior ridge is less -orominent proxirnally, the slope of the ventral mar-in leys steep, the anterior margin not producer' below an^! the sculpture coarser. OcGurrenoe .- lower Miocene: Bowden beds, l^owden, Jamaica. - 117 - Section Possularca Sossrrann. AROA (FO^JSUXAROA) ADAlvISI Ball. Area Goelata Oonrad, 1845, Pos. Med. Ter. U. 3., p. 61, pi. 52, fig. 2. Aroa GOelata Donrad, Tuomey and Holmes, 1857, Pleioc. ?os . South Carolina, p. 22, pi. 4, fi^s. 5, 6a. Hot A. ooelata Reeve, 1844. Area A dam si Shuttlevzorth, Guppy, 1874, Geol. Kag. Decade 2, vol. 1, p. 443 (check list). Area Adams i Shuttleu'ortn, Dall, 1385, Bull. I'ns. Oorapt. Zool., Harvard, vol. 12, p. 243, Area Adamsi ( Shuttlev7orth Mss.) Smith, 1888, JoTir. lin. Soc., London, Zool., vol, 20, p. 499, pi. 30, figs. 6, 6a. Barb at i a (Fossular£a) Adamsi ( Shuttlev/orth) Smith, Lall, 1898, Trans, "/agner 'S'ree Inst. 3ci., Philadelphia, vol. 3, pt. 4, pp. 629-630. Area adamsi Smith, Dall 8: Simpson, 1901, 3ull. U. S. Pish Gomm. , vol. 20, pt. 1, p. 461. Barhatia (Tossularca.) Adamsi Smith, Dall, 1915, Bull. IJ. 3. ITat. r.'us., no. 90, p. 121. Descripti on.- "Trapezoidal, disk widely and not profou::d- ly contracted; ribs numerous, alternated towards the base, tuber- - 113 - ciilatea , aculeated anteriorly and posteriorly; posterior slope depressed; umbo acutely anD:ulated behind; basal mar:-^in slightly arched; posterior marp-in obliruely truncated; beaks apr)roximate." (Oonrad, 1845) " Its sim.lated ribs of trailing blisters give it a remarkable similar appearance to Area lactea, which however has real ribs." (Dall, 1886) The Bov.'den specimens are small, moderately inflated, subtrape- zoidal in outline, slightly inequilateral; rounded anteriorly, ob- liquely truncated posteriorly, ventral and dorsal margins parallel, the ventral mar-in ve.y slightly contracte'l me-ially; posterior ridge low and broad; ujnbones relatively low, broad, place'! slight- ly anterior to the median horizontal; external sculpture of "blist- ers" more or less connect eci radially and concentrically, forming a delicate cancellated s culpture; beneath the blisters, which are invariably partially or even entirely removed, are faint, slightly elevated radial and concentric lines, as well as irregularly spac- ed concentric lines of growth; cardinal area narrow, excavate-"', the ligament seated on a subiimbonal triangular area; teeth in two ser- ies separated by a narrov subumbonal edentulous space; about fif- teen teeth in the posterior series and eight in the anterior; muscular imToressions well-define 1, bounded by raised rids-es which converge toward the umbones; inner margin of the v Ive usually entire. - 119 - Sinensions.- length, 8.5 mm.; alt., 6 mm.; semidiam., 2.2 mm.; length of hiiir-e, 5 mm. I^emark.?.- V.Tien oomnared with other specirens of this wide- ly ranging species, it is a'oparent that the Bowden representatives are sr.s.ller; the posterior ridge low^r; the ventral margin less contracted and the edentulous gap in the hinge shorter. The deli- cate cancellated sculpture formed by the "trailing blisters", as Ball has hapoilj- described them, is very characteristic. The blisters, however, are easily T^-orn off and all of the speci:-ens have only a few of them remaining, the surfaces from which the blisters heve been removed being almost smooth. The elevated rid,cres that bound the muscle scars appear to better advantage on the posterior scar. Recent specirens of this species apparently were early dis- tribute^-- under the manuscript name of A. adamsi 3hattlev7orth and Dall was the first, as Hiss Gardner has sho^^Ti, (1) to define It. ' (1). Mss. Smith, to whom the spe'3ics is usual:" y assigned, nin not publish his description until two years later. Occurrence.- Clirocene.- Tampa silex bo'S, "lorida (Dall, 1898, 1915). Ohipola rnarl, ""lorida (Dall, lOOS). Oak Grove - ISO - sand, Florida (Dall, 1^98). lo^r/er Miocene: Bowden beds, Bowden, Jamaica (Dall, 1898). Miocene.- Yorktovm formation, Virplnia fw-ardner, Tj5S.) Duplin formation, ITortli Carolina (Conrad, 1845, Dall, 1898, Gardner Mss.). Brunswick River bed, Georgia (Gardner, Hss.). Pliocene.- Oaloosahatchie ifiarl, ?lorida (Dall, 1898). ■Tacoama-/.' forrxiation, ITorth Carolina (Dall, 1898, Gardner, Mss.); South Carolina, (Gardner, Lies.). Croat an formation, Ilorth O|i.roli- na (Gardner , !:ss.)'^^ Pleistocene.- Sirmon's Bluff, South Caroli- na (Gardner, I.Iss.). Labelle, Florida. Recent.- Hatteras to ?emando IToronha, Brazil and east to Bermuda in 10 to 55 fathoms. - 121 - AHGA (FOSSULASGA ? ) 07ALINA Dall. BarTpatia. (?oss-ularoa ? ) ov gllra. Dall, 1898, Trans. V^agner Free Inst. Soi., Philadelphia, vol. 3, pt. 4, -o. 6?0, nl . 52, fig. 18. Descripti on.- "Shell minute, solid, ovate, ~,1 th rather in- flate! valves; beaks low in the anterior fourth, "orosog^rrate; car- dinal area short, narrow, smooth, or longitudinallj? striate, the pr.rt oooupied hy the ligament forming a small er-cavate" triangle 7/ith the ape:K: at the bealr in each valve; siiri'ace nearly smooth, s scrlptaire of faint, irregular, concentrie lines, crossed hy still fainter snarse rariiations \'7['i Ich are not pronounced enough to modi- fy the sixrf aoe ; inner margin of the valves smooth; muscular im- pressions large; hirge short v/it?i aboiit three crov/ded anterior and four oblique posterior teeth, the tv;o series separated by a wide n-ap belav the ligament. Ion. ?.2, alt. 2.5, diara. 2 mm." "A single specir.-ien of this cixrious little shell, with the form of a rucixla, -^he cardinal :;iar?in of a li'-opsis. and the teeth of an Area; was found in the marl. It shoulr!, perhaps be referred to Lissarca Smith." (Dall, 1998). Type locality., Bowden, Jamaica. Renmrks.- Two vslves, one from each collection, of this - lf^2 - puzzling form are present. I"^ oertainly is not a tj^pical "^osguI- arca and probably should be referred to a new section. The umbo is almost anteri-^r in position, so tliat the shell is very inequi- lateral, "our anterior and five posterior teeth are present, and in both series the teeth, are more closely spaced than in the spec- imen figure -1 by Dall. Ocourrence.- Lo-z/er Miocene: Bowden beds, Bowden, Jamaica. - 127' - Subgen'us Scapharca Gray. Seotioii Scapharca s. s. ARGA (3GAPIIARGA) KAIIDOITATA Dall . Area oonsobrina Gupp;, 1866, Quart, Jour. Oeol. Soc . London, vol. 22, p. 293 (non Sowerby, 1850). Area oonsobrlna Guripy, 187^, Geol. Iv'as:. , Decade 2, vol. 1, p. 44.';, (check list) ex oarte, non Sower'by, 1850. IJot A. consobrlna d'Orbifmy, 1844. Scapharca f 3ca-oharca) halidonata Dall, 1898, Trans. Wa^-ner Free Inst. 3ci., Philadelphia, vol. ?, pt. 4, pp. 646-647, pi. 55, fip". 24. Description.- "Shell sub equi valve, ovate, oblique, inflated; bealrs rather high, strongly bent forward, almost reaching the int- erior fourth of the length; left valve larger, with about thirty- four clear-cut, elegci.tly sculptured radial ribs; the anterior dozen ribs are usually dichotomous or deeply sulcate ; the ribs on the middle of the shell are grooved nrith one or t\vo shallow, sharp, incised lines; the more -oosterior ribs ere wider and flatter v/ith three or more grooves; those on the posterior dorsal slope are angiilar, narrower, and usually have not more than one groove, which is nearly obsolete; the concentric sculpture is of evenly spaced, fine, elevateri lines arched in the interspaces and finely nodulat- - 1;'4 - ing the anterior ribs; the sculpture is similar on both valves; the anterior end of the shell is rounded, the base arcuate, the posterior end oblique above axA produced belov?; the ends of the hinge-line are angulate^^; the cardinal area is moderately wide with about three concentric lozenp-es o-;tlinerl by the grooving; the hinge-line is straight, the teeth numerous snd mostly vertical, the two series not interrupted., the posterior distal teeth tending to become irregular in the adult. long, of shell 55, of hir^^re- line 41, alt. 40, dian. 40 nm. ; large S'^ecimens reach a length of 68 mm." (Dall, 1898). ? yp e locality.- Bow den, Jamaica, Angle between the ant erib-dorsal margin and the antero-later- al margin almost 90°, that between the postero-dorsal and postero- lateral about 125°; anterior radial ribs about equal to the inter- spaces, but the ' posterior ones broader; in the anterior portion of the shell the ribs have a relatively broad and deep sulcus which extends half of the distance from the raar.sin to the umbo; toward the central portion of the shell the sulcus occupies only the distal third or fourth of the ribs and becomes progressively shallower and narrower until in the central portion of the shell it is Lierely a sharp line (one or tv/o of vAiich may be present); ribs immediately anterior to the posterior slope broader and hav- ing three or four inconspicuous lines; those on the posterior - Ih5 - Slope lov7, flat, relatively broad, and with one or two, usually faint, lines; closely and evenly spaoe-^ coneentric lines present, producing nodules on the ribs, e2:ceot on those on the posterior slope and a few i!:^mediately anterior to it, the nodulations being most conSDicuous on the proximal half of the ribs; inner margin of the shell deeply crenulatei. Dimensions,- Length, 59 mm.; alt., 45.5 mm.; semidiam. , 20 ram.; length of hinge- line, 40 mm. Remarks.- Individuals of this species are very abundant, in fact, i.t is the most abundant Area, and all stages of growth are represented. Yoimg forms have a shape that is noticeably different from that of the adults; the inper part of the posterior lateral margin is not obliquely tru: cated or the truncation is not oro- noujice'"! and the lower part of the same margin is not as much nro- duced, so that the angle between the postero-dorsal and postero-lat- eral margins is less obt\;se, and the entire posterior lateral mar- gin Dtraighter. Other differences between young and adult are apparent when details of sculpture are consideree. On adolescent shells the svilcus aT)T)ears on only a few Df the anterior ribs and the lines on the posterior ribs disappear; #iile on young shells the ribs in even the extreme anterior portion of the shell are not sulcated, in other words, there is a progressive diminution in the number of anterior ribs that display siil cation. Some immature - 12 6 - forms, left v.^lves in oartien.lar, are more inflated than the typic- al form and have more deeply channeled interspaces. This is the species which &upny identified as A. sonsohrina Sovi,'erby (not A. consobrina d'Orhip-ny), •;7hieh was described from Sa.nto Domingo. The relations between hall ^. on at a and SowerbyAs oonsobil na and the question of noraenclat'!:ire is discussed under the folloviang variety. Occurrence.- Upoer Oligocene.- Ouracao (Dall, 1898) Gumana, Venezuela (Gupoy, 1874). Lop/er I.'iocene : Bowden beds, Boivvden, Jamaica, (^y^-'j 'ek<.,'Bi^: D./i^e^B). - 1.' ARGA (SGAPHAROA) HAXIDONATA var. HI3PAFI0LIA n. nom. ■\roa oonsobrina Sowerby, 1850, Quart. Jour. Geol. Soe. london, vol. 6, p. 52, pi. 10, fig. 12. Arcs fAnadara) oonsobrina Sowerbj;, '"-abb, 1872?, Trans. Am. Philos. Soo., new ser., vol. 15, p. 253. Uyn. excl.) Area oonsobrina Sowerby, Gupn.j, 187!^, Geol. Kag., Decade 2, vol. \^ 1, p. 447. (check: list), ex parte. Area oonsobrina Sowerby. Guppy, 1876, Quart* Jour, Geol. Soc, london, vol. 52, p. 551. Hot A. oonsobrina ri'Orbigny, 1844. ? Area of. oonsobrina Moore, Toula, 1908, Jahrb. Z.-k. geol. rJeich- sanstalt, vol. 58, T^p. 717-718, ol. 27, fig. 1. Hot A. oonsobrina Sowerby of Guppy, 1866 (= A. hali(ionata Dall) or Gabb, 1881. Description.- "Testa oblonga, oblioua, aequivalvis, ra'^ia- tim costata, lateribiis superne angiLlatis, antico infra rotundata, postico rotu dato- anp-ulato ; costis angustis, numerosis, plerum- que quadratis, et decussatis, ad basin sulcoteniji divisis, posti- cis fere laevibns, planulatis; area cardiijali latiusulca." (Sow- erby, 1850). Type locality.- Santo Domingo. - -Ip.d - Shell larp-e, su'btrapezoidal, the length more than one and one-half times the height, inflated; um'oones relatively low and flat, strongly hent forward, sitiiate^ at almost the anterior third of the length; angle between antero-dorsal and ant ero- lateral r.iar- gins ahout 90*^, that "between postero- dorsal and postero-lateral margins about 130°; anterior lateral margin ronrided; posterior lateral margin obliquely truncated above and prorluee- below; post- erior half of ventral margin subparallel to the dorsal margin, anterior '^ alf gently arcuate; e'temal sculpture the same as on the typical halidonata; cardinal area, hinge and interior mar- gin as in halidonata. Dimensions.- Length, 70 mm.; alt., 44 mm.; semidiara. , 21 ram. ; length of hirjge-line, 52 mm. P.emarlrs . - It is here proposed to consider Area consobrina Souerby a variety of A, halidonata Dall. Althouj?h Sowerby's des- cription is brief and inadequate, the accom"panying figure is satis- factory so that there is little doubt as to the salient features of his consobrina. Unforttmatelj , hov7ever, as Dall has pointed out (1), consobrina had been used in 1844 by d'Orbigny (2) for a fl). Trans, '''agner Free Inst., Sci., Philadelphia, vol. S, v>t, 4, p. 647, 1338. (2). Pal. ^rancaise, f Terraine Gret.) vol. 5, op. 209-210, -ol. 511, figs. 4-7, 1844. - 129 - ■ form from the Feocomian of the Paris Basin. Thus Sowerhj^'s name is preoccupie"', althou?rh d'Qrbip-n^'s Iroa co.nso'brina is a Cucullae.?, In the coljections at hand cOuit adults of halidonata var^' somewhat with re?rard to shape and the height of the umbones. Ihe ty^^ical halidonata is relatively high and has high, prominent ura- hones, hut there are variants in the direction of greater elonga- tion and lower beahs. The end produe"^ of such variation is the form describe"! by So^erby as Area consobrina« wiiich differs from A. halidonata in being more elongated, in having a straighter base line and lo'v7er and flatter umbones as Dall has shown. (1) (1). loe. cit. In addition, the -^mbones of Sowerijy's consobrina are plsced slight- ly further toward the middle of the shell and the urjoer portion of the posterior lateral margin is more oblique, in other words, the angle betvreen the postero-dorsal aiid postero-lateral niar.~ins is more obtuse. Since these differences are scarcely of specific grade, and since, moreover, the end r)roducts are almost complete- ly connected, it seems better to consider the more elongate form as m.erely a variety of halidonata. In the collections at hand there are only three large right v-.lves that can vath certainty be referred to the variety, although, as state"^. above, some of the halidonata forrris varj in that direction. The absence of any small- - i:^L. - er SToecirnens of hiSDaiiiolla nay be diie to the ^xrioertsinties of of Gollection, but it is possible that the ^voung forins differ so li-^tle from halidonata that they cannot be separated. The Santo Doming-lan forms that G-abb determined as A_, oonsobrina Sov;erbj- are typical, but to place A. florid ana Jonrad in synonymy v/as an error. It is orobably safe to suspect that the citation of Guppy for the occurrence of oonsobrina in"Haiti" refers to hispaniolia, but it is i-incertain whether the Jumana specimens are halidonata or its variety; 7abb's Oosta Siean Pliocene oonsobrina (l) is scarcely the same as the Santo Dominorian fonii, being- higher and (1), Jour. Acad. TTat. Sci., Philadelphia, 2nd ser. , vol. 8, p. 378. 1881. more convex. Toula is mistalcen in assigning consobrina to Moore, whose description of "Some Tertiary Beds in the Island of San Domingo" immediately preceeds Sov;erb^ 's description of the shells. The single Gatun specimen is go poorly preserve! that it is difficult to determine what it actually is. Toula comments on the marked dichotomy of the posterior ribs, a feature which is most character- istic of hispaniolia. 'The Miocene (Duplin) and Pliocene (Waceamaw and Oaloosahatchie ) - 131 - A* lienosa Say (1) of the same size has a similar appearance, hut is more evenly rotmded anteriorly and has a slightly more arouate base, more ntuneroiis and flatter rihs which have a more definite median sulcus and also a secondary sulc-as on either side and are more obviously and finely nodulated, '■'■^le recent 7/est Indian A. secticostata Heeve (2) also is more completely rounded anteriorly (1). Am. Oonch., pi. 36, fig. 1, i;:30. (2). Oonch. Icon., Ar^a, f i^- . 38, 1844. (= A. fori dam Oonrad, 1^69) and has vvlder interspaces. Occurrence.- Uprier Oligocene.- Santo -^omingo fSowerby, 1S50; Gabb, 1873; Guppy, 1874, 1876) TGums-.na, Venezuela (Guppy, 1874) ?Gatun formation, Panama (Toula, 1908). lower Miocene : Bowden beds, Bowden, Jamaica. - 1' AROA (S3APHARGA) PZEPLSURA n. sp. Sesoription.- Shell of medium size, heavy, decidedly inflat- ed, moderately inequilateral; "base gently and evenly rounded, sub- truncated posteriorly, rounded anteriorly; ujnbones moderately high, full, prominent, with an inconspicuous mer'ian suloation, situated at about the anterior -fcird of the length; e:-ternal surface sculp- tured with thirty-three high, flat-topped radial ribs of imiform v;idth, separated by narrower dee pi; -channeled interspaces; on the posterior slope the ribs lower and the interspaces v^rider than in the othrr portions of the shell; concentric scul^^ture of fine, usu- ally evenly space-^ raised lines, producing 1ot;v nodules on the ribs, except on those on the posterior slope ; cardinal area moderately "dde Vv'ith two ligament grooves behind the umbo; teeth numerous, vertical, except at the posterior end, the series continuous; inner margin with deep crenulations. Dimensions*- length, 23.5 mm.; alt., 17.5 mm.; semidiam., 9.6 mm.; length of hinge, 17 mm. Remarks.- A. t)erToleura is represented by two detached left valves. It resembles most closely individuals of the sane size be- longing to the soecies halidonata, but differs by being proportion- ately more elorigate, heavier, less compressed in the posterior dor- sal region,, more inflated and by having fuller, more prominent beaks. "1 r^ rr higher rihs and more deeply channeled interspaoes. V ioxirrenoe.- i-ower Miocene : Bowden beds, Bowden, Jamaica. - 154 - ARC A (SOAPHARGA) IlTAilQuILATSRALIS Guppy. Aroa ina eg Txilate rails Guppy, 1866, Q-uart. Jour. Geol. Soc. London, vol. 22, pp. 29.'^-294, pi. 23, fig. 2. Area inaequilateralis '^-appy, 1874, Geol. Kag., decade 2, vol. 1, p. 443, (check list). Seapharca ( Scapharca) inaequilateralis Guppy. Dall, 1898, Trans. v?agner Free Inst. Sci., Philadelphia, vol. ?■ , 'ot. 4, p. 647. Descripti on.- "Shell transverse, sli^tly oblicue, very in- equilateral, produced posteriorly; valves with ahout 30 crenate radiating ribs, single on the disk, v/here they are not broader th?3n one-third of their interstices; double anteriorly and posteriorly, 7;here they are ecual in V7idth to the interstices; hinge-line long straight, forming an abrupt angle m th the rounded anterior margin; posterior margin v/ith an oblique slope." ( Gunp;- , 1866) Type locality.- Jamaica. Shell small, thin, elongate, subovate, moderately inflated; umbones low, situated at about the anterior third of the length; the straight dorsal margin forming sharp angles with both lateral margins; angle between the dorsal and anterior lateral margin be- ing slightly more than ^0°, the one betv.'een the dorsal and post- erior lateral margins about 135^; en^treme upner portions of ant- 1:35 - erior and posterior lateral raar^-ins fee'bly incised on adidt shells; anterior margin roimded; up-oer portion of posterior margin oblique- ly trimoate"., lower portion produced; ventral margin sloping toward the posterior end; sculDtiire of the two valves sirdlar, consisting of about thirty, clear-cut radiating ribs, the one adjacent to the antero-dorsal margin usually small and .arrow; the next eight to tv/elve broad, being wider than the interspaces, and having a shal- low, broad median sulcus; ribs in the centrr^l portion of the shell narrow, usually less than half as wide as the inters'oaces, and usually square; the posterior ribs, nine to eleven in number, much wider than the intersr)aces, flat and with a narrow groove (rarely two), almost or entirely obsolete on those ribs in the extreme post- ero-dorsal region; concentric sciUpture of fine, closely set rais- ei lines, producing on the sulcated anterior ribs a double row of nodules and a sing'le row on the undivided medial ribs, the nodulat- ion of the median ribs usually more conspicuous on the left valve; posterior ribs not affected by the concentric sculpture; cardinal area very narrow, v/ithone to three ligament grooves behind or ijnder the ujnbones; teeth fine, closely set, short, vertical (except in the posterior region), uninterrupted, but the me "'ian teeth very short, inner margin of the valves deeply crenulatei and from the crenulations faint lines, m.ost noticeable in the posterior region, run up to war-' the umbo. o - Diniensions.- Length, 31 nira. ; alt., 16.7 vAm. ; semidiam., 7 mm.; length of hinge, 19 ram.; length, 28 mm.; alt., 15.8 mm.; semidiara. , 6.5 mjn. ; length of hinge, 11 mm. 5emar':s.- Jompared with the average Scapharea the shell of iiiis species is decidedly tb in and the sculpturing is elegaiit. Individuals belonging to this snecies are numerous and they may he inraediately recognized by their small size, thin shells and inter- nal radiating lints. -"he differences in the size and sculpturing of the radial ribs in different areas of the shell are enhanced by the delicate chiseling vihich characterizes the sculpture through- out, '-^e anterior ribs are nodulated and sulcated; the me-'ian ribs are na-row and usually not prominently nociulate''; the poster-, ior ribs are broad, low and smooth, exGe"ot for a shallow groove. A few forms shov/ .a very faint and shallow sulcus on the umbo. Some young shells have the dorsal postero-lateral nargin more deenly in- cised than in the case of the average adult. A. inaeguilateralis is closely related, as Dall (1) has pointed out, to A. latidentata (l). loc. cit. Dall (2) of the Ohipola marl and Tampa siles be is, but nay be dis- iP-), Ice. cit., p. 638, pi. r-g, fig. 15, 1898. - l.:^7 - tinguished by its more prod'aoed posterior margin, the varying char- acter of the ribs in different -portions of the shell, thinner shell, and finer^ shorter and more numerous teeth, jlnother species from the same horizons, A. (Sjapharoa) hr.-ooniela Dall fl) is readily dis- tinguished when adult since the ^loridian foim is much larger, more (1). loc. eit., p. 657, pi. ?5, fi^-. 1, 1898; Bull. IT. S. Fat. Muc, no. 90, p. 121, pi. 17, fi?. 7, -ol. 21, figs. 17, 18, 1915 inflate", tn.incated posteriorly rather than acutely rotuided and the ribs, except those on the posterior slope are deeply channele:"; young individuals of the same size as inaeguilateralis are similar In a-opearance, es^cially those from the silex he's, because of their thin shells, but they always have sulcate'l ribs and are not quite as much rirodiice i and rou-~.ded posteriorly. A, gatunensis Toula (S), described fit) m Oatim, Panan;a is larger, '• : -ier, more (2). Jahrb. E. S. Geol. Reichsanstalt , vol. 61, p. 4-91^, ^dI. 50, fig. 4, 1911. convo", less produce''"' posteriorly, the anterior ribs are more deep- ly sulcate, the me'lian ribs narrower and sharper and the ribs ir.ined- iately anterior to the posterior slope are sulcated. Brov/'n and Pilsbry have described another more closely related Gatun form - - 158 - A. dariensis ; (l) it is larger, lees produced posteriorly-, tlie curve of the anterior 'THrrrin is fuller, so "ftiat the ventral margin (1). Proc. Acad. Hat. Sci., Philadelphia, vol. 63, op. 352-365 pi. ^2, fig. 10, 1911. does not descend posteriorly; the type of sculpture is the same, but neither the nodailerj or the -^onc^entric lines in the interspaces are as prominent on right valves, on left valves the nelian rihs are wider and the posterior rihs occasionallj? have tv/o rov73 of fine nodules. Guppy's description, though brief, considered most of the diagnostic features. His figure, however, was drawn from an im- perfect valve; the incision of the uppermost oortion of the antero- and postero- lateral margins is deeper than normal and the shell should be more produced posteriorly. Occurrence.- lower Miocene: Bowden beds, Bowden, Jamaica. (Guppy, 1866, 1874; Call, 1898) - l;-0 - AI^OA (3GAPEAK0A) DOIAOIA Dall. Soapharea (Soapharea) donaoia Dall, 1890, Trans. .Vagner 7ree Inst. 3ci., P iladelphia, vol. 7^ , pt. 4. p. 649, pi. 33, fig. 15. Deserj-ption.- "Shell small, donaciforra, moderately pliamp, with rather elevated orosocoelon.s be a>s at about the anterior third; valves almost similarlj; sculptiired ; left valve with ahout twentj?- fotir low, strap-like, narrow radial ribs id. th somewhat vTider inter- spaces; the ribs are plain, anooth, and entire on both valves; on the left valve the interspaces are crossed by numerous equidistant elevated lines ~;hlch do not appear on the ribs; on the right valve the interspaces are only marked by lines of grov/th; hinge-line short, cardinal area very narrow, smooth; anterior end larger, rour.ded; posterior end produced and attenuated; hinge teeth small, similar, slightly divergent; internal margin of the valves v,'ith deep short flutings. Ion. 6.8, alt. 4.5, diam. 5 ram." (Dall, 1398) T7/pe looalit;,;.- "Bowden, Jamaica. The umbones are relatively 'r-'-gh and conspicuous. On the umbo of the right valve a verj- shallow and narrow sulcus is usually present. Tov/ard the ventral narrin this sulcus broadens, but al- though slie'htly emarp-inating the me^'ian ventral nargin; it is never prominent; on the left valve the sulcus is absent or very poorly - 140 - defined. The ribs - four to six in number - in the suloiis are nar- rower and flatter than the others; this is true also of the ribs that have a corresponding position on the left valve. On imworn valves fine, evenly and closely- spaced concentric lines, usually more prominent in loft valves, appear in the intercostal spaces; the median teeth are short and vertical, vshile the anterior and posterior ones are long-er and slig-htly oblique. The deep, short crenulations of the internal nnrgin are obsolete in the melian vent- ral region, i. e., in the region of the external median sulcus. Dimensions.- Right vnlve: Lenp:th, 9 mm.; alt. 6 mm.; semi- diam. , 2.5 mm.; length of hinge 5 ram. left valve: length, 9 ram.; alt., 5.2 mm.; semidiam., 2.5 mm.; length of hinge, 1-.8 mm. Remarks.- This is a small form, but there is no doubt that it actually is adult, since it is r.'ell re-nresented by an amazing n^imber of individuals of various staR^es of grov;th. Because of its shape and relatively high urabones it is sharply set off from the ; oui g of associated Scapharcas. Occurrence.- Lower Kioeene: 3ov/den beds, Bowden, Jamaica. (Dall, 1898). - 11-1 - ARGA (S3AHL12CA) PP.EPKAim n. sp. Aroa (Scaoliarca) aiirioula ta Lamarok ?, Dall, 1898? Trasas. V/agner Free Inst. Sci., Philadelphia, vol. 5, pt. 4, p. 649. Description.- "^hell of merlitun size, decidedly inflated; post- eriorly the angle hroadly prc^ucefl and the raarrin slightly insinu- ated near the dorsal angle; anterior margin romKling by a broad curve into the gently and asyimnetrically arcimte base; both extre- mities of the" straight dorsal margin angular; umbones medium height, full, prominent, at about the anterior third of the length; poster- ior ridge strong, rounded, the posterior slope excavated; left valve slightly lar -er, ^;7ith thirty-two, shai*ply chiseled, soixare radial ribs separated by interspaces wider than the ribs in the ant- erior and meciian portions of the shell, but narrower in the poster- ior portion; in the anterior half of the shell the ribs diehotomoi:is distally, on the posterior slope flatter and broader; all the ribs except those on the posterior slope nodulated by numerous, sharp concentric raised lines that persist across the intercostal s-naces; right valve with thirty lower and broader radial ribs, the inter- spaces being of about the same vadth in the anterior half of the shell and narrower in the posterior half; only the anterior six or seven ribs diehotomous, the nodulation United to the anterior ribs, the nodules not as sharp as on the left valve; cardinal marprin of medium - 142 - width, crossed bj" three to five concentric ligament grooves; teeth numerous, strong, vertical, the series heing straight and continu- ous; inner margin of the valve v;ith short crenulati^ns. Dine ns ions .- Right valve ( ty-oe ) : Len~th, 35 mm.; alt., 24 ram.; semidiam. , 10 mm.; length of hi/ge, 22 mm. left valve: Length, 38 ram.; alt. 25 mm.; semidiam., 12.5 -^-m.; lenp-th of hinge 24 mm. Remarks.- A. prephaina is very close to the recent A. auri- cula ta lamarck (1) and undoubtedly is in the same direct genetic (1). Anim. sans Vert., vol. 6, p. 43, 1819; Reeve, Gonch. Icon,, Area, pi. 6, fig. 35, 1844*. series. The 3o™rlen form is smaller, has more numerous, usually finer, lower and more conspicuously nodulated radial ribs and much narrower interspaces. It may be distinguished from the associ- ated Scapharcas by its "auriculate "outline. The single poorly preserved valve in the National !.!useum Collection, which was doubtfully referre'I to a\\riculata by Dall, apoears to belong to this species. Occurr enc e . - ipy,- er I.'iocene: Bov;den,beris, Bowden, Jamaica. A5:3A (SOAPHAROA) V/ORLEIII n. Gp. Description.- Shell niedimn-sized, moderately inflated, hec.vy, eloiTgate; dorsal marg-in long, straight, angular at "both e--tremities ; ■ujievenly romided anteriorly, subtrmie-ated posteriorly; ventral mar- gin asyirane trie ally arcuate; umbones inflated, lor, rith a very faint median sulcus; left valve se-.ilpturs'? with thirty- tv/o clear-cut, square radial ribs of almost constant width thro^^.Q•hout, exce-ot in the ex- treme anterior and posterior regi'^ns, flattened on the posterior slope; interspaces narrov/er than the ribs; except on the posterior slope the ribs and interspaces crossed by concentric raised lines, sharp in the intersiaaces and nodulating the ribs; risTht valve vath thirty or thir'.y- one lov/er and usually narrov/er radial ribs, seoa- rated by interspaces of about the same width; concentric lines prominent in the interspaces, but nodulsting only a few anterior ribs; cardinal area narrow, with one or two liprament grooves; teeth small and straight redially, longer at both eu'^s and slightly ob- lique at the posterior end of the series; inner mar-rin with short, deep crenulations. Dimensions.- Length, 25.5 m:'.; alt., 17 •:m.; seraidiam. , 8.2 mm.; length of hinge, 18 nim. Remarks.- A. v;ordeni is characterized by its rather elongate - 1 -S ame and inflated form, thick shell and relatively high, imdivided ribs separated by deeply channeled interspaces. Yourig individuals are proporti-^nately less inflated than adTxlts and the umhonal snlciu is often more prominent. A. inaegiiilateralis is of about the ss size but Is much thinner^ more produced posteriorly, less inflated and has finer ribs; A. per-ole ura is hig-her, heavier, has fuller, more prominent beaks, wider ribs and narrower interspaces. The Ohipola A. hy come la Dall (1) has the same general form, but is much (1). Trans. .Vainer ?ree Inst. Sci,, Philadelphia, vol. 3, ot. 4, pp. 657-638, pi. 33, fig. 1, 1898. larger and has lower, deeply sulcate ribs and a wider cardinal area. This species is named for I'r. Stanley 7orden, of the Karyland Geological Survey, '"'ho gave efficient assistance in the prepara- tion and preliminary determii^iation of the material. Occurrence^. - Lower l.'iooene: Bov;den beds, Bowden, -Jamaica. - 145 - AROA (SOAPHARGA) AGHASTIIA n. sp. DesGription.- Shell an all, thin, moderately inflated, high- er posteriorly, oompressed in the posterior dorsal region; poster- ior nmrgin triuicate:!; ventral margin curving gently in the poster- ior half and more rapidly in the anterior half, anterior mar!?in carving abruptly upward; both lateral marrin Joining the dorsal mar- '^'in by sharp arigles, the posterior angle being slightly more than 90°; umbones low, relatively brosd, placed at ahont the anterior third of the length, with a very slight nsdian sulcus; e-rternal surface sculptured with forty lov;, narrow, flat radial ribs, broad- er and flatter on the posterior slope, separated by narrower inter- spaces; in the interspaces faint concentric lines, ^'^ersistent across the ribs, except those on the posterior slope, producing slight nodulations; cardinal area of me-iura width, with faint longitudinal strlations; . ;.-.je long, straight, '-.ith ntunerous fine teeth; inner margin v;ith numerous, short crenulations. Dimensions.- Length, 21.8 mm.; alt., 12.8 ram.; semidiam., 5 ram.; length of hincre, IG mm. Reracrks.- The compressed posterior dorssl region produces an auricula te effect which is more pronouncer! on yomig individuals. The ventral mar-in ascends rapidly toward the anterior end. These features, together with the numerous narrow, flattened radial ribs and small size of the shell, are distinguishing characteristics. - 146 - Youn<=r iri'^ ivi r!n als , It sides "being more auriculate, have a greater difference in altitude "between the posterior and anterior ends, i. e., the ventral niar?rin ascends core rapidly anteriorly^ and the ■am"bonal sulcation often persists to the ventral margin, thus pro- ducing an almost bilobed appearance. Considerable difficulty was experience'^- in distinguishing "between the young of ap:nastha and wordeni, those belonging to agnastha are usually more elongate, more auriculate and have more numerous and finer ribs. The adults are readily separable, since the shell of v;ordeni is heavier, larger, higher, more inflated and its ribs are coarser and high- er. ?rora the anricule te perphaina, a^nastha differs by being small- er, thinner, more elor^ate, less inflated and by having more nujn- erous and finer ribs. A, acompoa Pall (1), of the ^hipola fauna. (1). Trans, '-^agner Free Inst. 3 1., Philadelphia, vol. 3, pt, 4, p. 64S, pi. 33, fig. 15, 1898. is more produced anteriorly, has a straighter base, vidder ribs and the anterior ribs are divided. Occurrence .- lower Miocene: Bowden beds, Bowden, Jamaica. - ll-V ARGA (SOAPIIAHGA) THOMASEIISIS n. sp. Description,- Shell, s;nall, well inflated, moderately inequi- lateral, slightly produced posteriorlj-; anterior end of the dorsal mars-in rou: ded; ventral margin almost symmetrically arcuate; rourided anteriorly and posteriorly; umhones moderately high, plac- ed anterior to the me'^ian horizontal, the tip very sli.^htly impress- ed medially; e" ternal surface sculptured v;ith thirty-six narrow, square-topped, clocely set radial rihs separate! by narrower inter- spaces; the anterior seven or eight ribs and the accompanying in- ters-oaces relatively wide; the nezt eight narrow and the succeed- ing ones -oroprressively sllp-htly broader, those on the posterior slope broadest and flatest; concentric sci.ilpture of irregular, in- cons-oicuoua lines v/hich faintly and unevenly nodulate the anter- ior and median ribs; cardinal area moderately v/ide, with a single ligament groove behind the umbo; teeth numerous, vertical, except at the posterior end of the series; ini'ier m.argin of the shell or- nam.ented with numerous, deep, long crenulations ; interior of the shell mar'rer' with fine, inconspicuous radiating lines. "Dir.ensioiTS.- Length, 19.5 mm.; alt., 12 mm.; semidiam., 5.1 mm.; length of hinge, 14 ram. Hem.arks.- Phis species is re-':)resent ei^ by a left valve. It may seem unfortunate to add another species to the alreat^y long list of Bowden Scapharcas, especially the species rests on a single - 1^ valve whicli may be iri'-at-are. The curved outline at the juncture of the anterior and dorsal margins, the almost sym-etrieal curve of the base, the numerous narrow radial ribs, the long, narrow crenulations of the inner marr-in are all distinctive. -hese feat- iires, together r;ith the rather high, inflated form, distinguish A. thoniasensis. It ^oould be arlded that the posterior end of the dorsal margin of the specimen is broken off. A. agnastha has abo".t the sane number of ribs, but they are wid- er and the shell is more elongate and auricula te. A. \7o rdeni as almost the same shape, but its ribs are much coarser and the ant- erior end of the dorsal marp:-in is sharply angulated. Occurrenoe.- Io"-er Miocene: Bowden beds, Bo^rden, Janiaica. - 149 - ScGtion Argina Graj' . AROA (AI^GirA) TOIEPIA Dall var. MI3R0TERA n. var. ScaiDharea (Argina) tolepla Dall, 1B98, Trans. Wagner ?ree Inst. Sci., Philadelphia, vol. 5, pt. 4, pp. 649-650, pi. 33, figs. 7, 3. (ex parte). Description.- Shell small, well inflatecl, the greatest in- flation and greatest height of the shell behind the me-'ian horizon- tal, compressed in the distal pos tero-dor sal region; right valve smaller, more rounded, low> r posteriorly than the left; antero-dor- sal margin very short; rounded anteriorly ; "base sloping tov/ard the posterior end; posterior lateral margin scarcely rounded below, but CL-rvi^.g to meet the dorscl mar~ln; umbones tumid, broad; med- ia.lly sulcatei, placed at about the anterior third of the length; left valve sculptured with thirty-sis to thirty-eight strong radi- al ribs; anterior and median ribs subrounded, separated by narrow- er interspaces, and nodu].ated, the nodules being connected across the interspaces by raised lines; posterior ribs low^r, flatter, separated by interspaces of almost the same v/idth, and sm-ooth or inconspicuo^isly nodulsted ; right valve with twenty-eight to thirty sharply sculptured, obscurely nodulate''. ribs separated by deeply channelled interspaces of the same v/idth or slightly wider; card- - IGO - inal area as in the typical Argina; hinge with about fifteen post- erior and nine anterior teeth, the tvro aeries im interrupted; inner marsTin of the valve deeply crenulated. Siraensions.- Length, 6.1 mm.; max. alt. 5.9 mm.; semidiara., 1.8 mm. ; leng''"h of hinge, 4 mm. Remarks.- '^he descilption of the right valve niay he incorrect since the only right valves at hand are very small forms which are douhtfiilly referred to this variety. It seems iir.prohahle that only left valves of one species and rifht valves of another should aripear and therefore these right valves are considered microtera. although they display characters different from those that v/ould be expected. Right valves of the section Arjrina are smaller than left ones and usually have fev;er and lower ribs, but in this ease the flisnarity in the number of ribs is inordinate and the ribs are more sharply sculptured on the right valves, even projecting be- yond the margin in the anterior and meUan regions of the shell. In addition the right valves are more rounded aad have umbones ^hat are only obscurely suicated. This form has previously been referred to as A, tolepia, a name which Dall proposed for a species from Santo Domingo and Ou- m^na Trhich Guppy (l) erroneously identified with the recent A, (1). Geol. I'ag., Decade 2, vol. 1, p. 'AZ (check list). - ir-1 - pexata Say (-A. oampechensis Dillwyn). The Bowden specim.ns are however, muoh smaller than the typical tolepla. proportionately less inflated, slightly more romided posteriorly and have sulcated iimbones, a few more ribs and narrov/er interspaces. In view of these differences it seems advisable at the present tirnc to consider the Bowden form a depauperate variety. The yormg of A. oampe c hens is Dill^vynfl) of the same size have fl). Descr. Oat. Rec. Shells, vol. 1, p. 208, 1817. a longer postero-dorsal margin which meets the late ml margin at a sharper angle, a straighter base, shar-ner and more conspicuous- ly nodulated sculpture and unsulcated umbones. A. brightonensis Maury (2) and A. billingsiana llaury (Z), both from an Upper Oligo- (2). JouJT. Acad. Hat. Sci., Philadel"ohia, 2nd ser., vol. 15, pp. 46-47, pi. 8, figs. 4-6, 1912. (S). Idem. pp. 45-46, pi. 8, figs. 2, 5. cene horizon at Brighton, Trinidad, are more elongate, less in- flate"! and differ also in sculpture. Occurrence.- lower Miocene : Bowden be'^s, Bowden, Jamaica (Dall, 1-98)/ - If Section Ouiiearca Dall. AROA (OUITEARGA) OPTHAIJTA n. sp. De script Ion.- Shell small, cardiforni, hei.p'ht esceeclinp- the length, decidedly inflated, higher posteriorly, moderately inequi- lateral; left "valve larsrer, higher posteriorly, more inflated than the r i^-ht and having higher mnhones; riorsal margins short; rounded anteriorly and posteriorly, the curve of the anterior margin short- er and more convex than the posterior, passing mthoiit interru-ntion into the slightly curved hase; hase descending tovi^ard the posterior end; umhones high, tumid, subcentral in position, prosog^rate; ex- ternal surface sculpti^red v/ith twenty-six to twenty-eight radial ribs, conspicuously nodulated throughout on the left valve, ex- cept on the umbo, but the right iralve haviiig- only a few anterior ribs nodulated; cardinal area narrov/ behind the umbones, shorter and wider before; anterior series of teeth numbering eight or nine, vertical, forming an uninterrupted series, with the tv/elve to four- teen teeth of the posterior series; inner margin of the valve with short, deep crenulations . Dir:iensions .- length, 7.5 ::r . ; alt. 7.8 mm.; semidiam., 3.5 mm.; length of hinge, 4.5 mm. Remarks.- It is not i-nreasonable to assume that the sr:Hll valves that are fre only re-oresentatives of this form a.re immature. - 153 - Suoh a conclusion is natioral from a consideration of the charac- ters of the cardinal area which is more like that of the section Argina than would be expected in a Ounearca. The hinre and outline, however, are not arginoid, and it is probable that adult shells would have a more equilateral cardinal area. This is the only representative of the nujnerous races of high V-- Areas that have a rather inde-Tert iary distribution in the Qarib- bean ro^rion. Its cardium-li'"e form and extreme infl. ation are no tevi-orthy. Urbina (1) has described A. chavezi from the Miocene of Su- fi) . Bol. 3oc. geol. mexicane, vol. 5, iDt. 2, Top. 1?1-1?2, pi. 60, figs. 56-60, 62-65, 1910. ^Ci- ------------------------------- luzum, 3hipas, Ve-iao ; it reaches a mxieh larger size and is less roujnded, bein?' more "aroiiuced posteriorly and with a streighter base. A'oparently this species is decidedly variable, a form such as the one represented by fig. 63 closely resembling opthanta in outline; the Oaloosahatchie A. alcina Dal 1 (2) differs in a simi- (2). Trans. Wagner Jree Inst. Sei., Philadelphia, vol. 5, ^t , 4, pp. 555-656, pi. 51, fig. 5, 7, 1898. lar manner. The yomig of the recent 'Jest Indian A. cher^ni t?i - 154 - Philipioi (l) of the same size are more elongated, much less in- (1). Zeitschr. fur I.'al. , vol.. 8, p. 50, 1851, (= A. bio ops d'Orhlgny =A. orbig.^'i Zohelt). flater!, ';,'ith lar.'er and 'broader'-ambones. Occurrence.- lower Kiocene: Bowden beris, Bowden, Jamaica, - 1 Section Bathyarca Kobelt. AR3A (BATHYAR3A) H3KDERS0EI Dall. Soa-oharoa (Bathyarca) Ilendersoni Dall, 1898, Trans. I'/agner ?ree Inst. Sci., Philadelphia, vol- 3, pt. 1, p. 653, pi. 53, fif. 9. ■Qesoripti on.- "Shell very small, much inflated, the hirge-line as long as the shell, whi3h is of a roundel triangiilar form, with rather prominent prosocoelous healrs; left valve v:ith fine, elevated rounded concentric lines, crossed by closer, less prominent, and finer ra^'ial lines; in the rig-ht valve, as nsnallin this section of the genus, the radial sculpture predominates over the concentric, the latter though present heing inconspicuous; cardinal area mod- erately wide, the healcs heing nearly medial, the surface of the area longitudinally striated; hinge ^ith ahout five nearly verti- cal anterior teeth separated hy a wide unarmed gap from six or seven smaller, more ohlique posterior teeth; mar-in -^f the valves thin, entire, or microscopically crenulated; the inner edges of the ad- ductor scars slip-htly raise" above the inner surface of the valve. Lon. ?, alt. 2, diara. 2 mm." "This minute little species is obviously adult, and about ten - 156 - valves were o"btained. It resembles A. pectiinciiloides Scacchi (l) (1). Kotizie, etc., p . 25, Tab. 1, fig. 12, 181^-5. The 'Test Indian form has been separated as the variety orbiciilata Dall. (Bull. Mus. Oompt. Zool., vol. 9, p. 121, 1881; idem, vol. l.^, pp. 240-2^=1, pi. 8, fi.-r. 5, 1886. arid A. flomernTa Dall'" of the recent faima, but is sraller, more (2). loc. Git., pp. 121-122, 1.^81; loo. cit., p. S41, pi. 8, figs. 9, 9a, 1886. inflated, and more triangular than either of them." (Dall, 1898) Type loc ality.- Bow den, Jamaica. Remarks.- In the Diie rden collection there are only a few valves of this small, interesting species, but, strange enough,. a surprisingly large nimber is present in the Aldrich Collection. i'he shell is much higher posteriorly so that the anterior margin descends steeply, vrhile the posterior margin is only gently curved. The greatest inflation is in the melian posterior region. I7or the size of the shell the umbones are very broad; they are placed slirrht- ly anterior to the melian horizontal. Occasionally there is visible a very faint sulcus on the umbo, which when continued is on the anterior side of the mef^inn line of the shell and in rare cases it slightly insinuates the margin. As usual in the section, the - In? - left vglve is larger. Left valves in r)articnlar display a certain range of vcriation in convexity, the less conver fomis bavino- a narrower cardinal area and m^re o"blioiie anterior teeth. Among the specimens v/as a left valve which was quite distinct from the remainder in being more convex, in having a shorter post- erior dorsal margin and therefore a more convex posterior lateral margin, much higher and more incurved umbo and a wider cardinal area. Unfortunately the shell v/as not complete and in handling was irreparably broken. Tt is mentioned in the hope that future exploration will reveal its presence. The most closely related forms are, as noted above, recent srjecies. Occur re nce.-iorer Miocene: Bowden bC'-^-s, Bowden, Jamaica. (Ball, 1898). Section ibiadara Sraj;. ARGA (MADARA) DASEIA ,,. 30. Description.- '^hell of ms^iurasize, heavy, suTDrhornlDOiflal, elongate, much inflated, slip:htly hig-her in the posterior region, the anterior marsrin ctTrving broadly imto the gently arched ventral mar^'in; obliquely truncater! posteriorly; ixrabones high, decicle;ily inflate'!, the tip slightly Impressed medially, situated at about the anterior third of the length; left valve sculptured with twenty-six hiR-h, square radial ribs, separated by v/ider deeply chan- nellel interspaces; on the posterior slope the ribs lower and flat- ter, the anterior ribs about as wide as the interspaces; concentric sculpture of increment als, elevated at integrals, producing faint nodulations on the tops of the ribs and inconspicuous raisei lines on the sides of the ribs and in the Inters-oaces ; cardinal area impressec!, of moderate width, wider in front of the umbo, with five ligament grooves behind the umbo and five longitudinal striations before; hinge long, straight, v;ith fine numerous teeth, larger and slightly oblique distally; inner margin of the valve v;ith short, broad, deep crenulations. Pi tensions.- length, 31.5 mm.; alt., 19 mm.; seraidiam., 1'" mm. ; length of hirjge, 25 mm. - "^ "n - Remarks . - This species^ 1iie only representative of the sec- tioii Anadara, is foundefi on a single left valve. I*he elongate form, tiiick, heave shell, hip-h beaks and deeply sculptured radial ribs distinguish it from the. o ther Ar-as of the Bowden fauna. A. daseia ". s smaller than A. eampsa Dall (l) of the Ohoctawhatehie Miocene, more elongate, more oroduced posteriorly, vlth a more (1). Trans. V/acrner Free Inst. Sci., Philadelphia, vol. P, ot. 4, pp. 656-657, pi. 32, fig. SI, 1898. typical Anadara hinge. The Oaloosahatchie A. catasaroa Oall (2) is larger, more produce'!, posteriorly, with umbones that are more (2). Idem, iop. 654-655, ^] - :?2, fier. 20, 1898. anterior in position an^i sharply sulcated anterior ribs. Occurrence.- lower Ilioeene: Bowden beds, Bowden, Jamaica. - 160 - Subfamily Glj^cynierinae. Genus . .GLYGyi.SHIS Da Costa. GLYGYI'.IEHIS JAIIAIGEITSIS Dall. PectiuiGiilus pennacea Guppy, 1866, ■"v.ar't. Jour. Geol. 3oc. London, vol. 22, p. 29? (non lamarck, ISOl.). Axinea pennaoea Gabb, 137?, Trans. Am. '^riilos. Soc, nev/ ser. , vol. 15, p. 255 (non Iamaro>, 1801) ex -.xirte. Peetun cuius deoussatus Gunpy. 1874, ^-eol. ''^ag.. Decade 2, vol. 1, p. 443 (check list), ex rjarte. (non Linnaeus, 1753). Pectunoulus deoussatus Guppy, 1876, ■^-uart. Jour. Ceol. Soc. London, vol. 52, p. 552, (ex parte, non Linnaeus, 175S), Glyc:meris Jamaioensis Dall, 1898, Trans. V/agner Free Inst. Gci., Philadelphia, vol. 5, pt. 4, p. 608. Description.- " Moderate size, nearly circular, quite conve:';, externally sculptured v/ith fine, even, radiating striae, impressed at inter\'-als so as to give the effect of obsolete ribs, which are more apparent on the middle of the shell ; on the beaks some of the threads are stronger; rjnbones lov; and plump; cardinal area impressed, narrow, short, and smooth; teeth small, iminterrup- ted, about twenty-foiir in a"l, the line gently arcuate; inner r.a r- ffin flute:'., with a slight insinuation near the base in fro/it. - IGl - Long. 35, alt. 53, diam. 22 mm." (Dall, 1898). [gype local i't-y.- Bow den, t7araaica. Shell decidedly convex; umljones lov;, decidedly inflated; adults with the distal two-thirds of the posterior slope gently keeled, the point of impingraent of the keel on the posterior lateral rjarrin heiiog the dorsal termination of a trimoation extending ohliqnely dOL-mward to the postero -ventral margin, then Joining the even curve of the anterior half of the ventral mar-in; anteri^i-ly the straight dorsal margin passing rapidly into the broad curve of the azitero- lateral margin; the slope between the postero-dorsal and postero- lateral raaro-ins less abrupt; external sculpture of many very lov;, inconspicuous radiating ribs, narrowing into more prominent elevat- ed lines on the umbones and absent in the extreme antero- and post- ero- dorsal regions; fine, equally spaced radinting striae and enn- ally fi;.e, but less prominent, concentric striae superimposed on the ribs and narrower interspaces, the two producing a minutely can- cel! ated sculpture visible only on unworn valves; cardiral area very narrow; hinge-plate gently and imiformly arched; teeth relat- ively small, usually 12 before and IS behind, the umbo; buttresses of the muscle-scars not prominent, Dimensions.- Length, 55 mm.; alt., 7,^- rm. ; semidiam. , 11.5 mmi. Remarks . - iais species is most abundant of the miembers of the genus. Individuals that have assumed adult features are character- - 16;^ - ized Tdj' the imique posterior keel, which, though Slip-ht, is note- worthy, and the ooncomitant oblique truncation of tl .'-ero-lat- eral margin. Inmature forms do not display these features, "biit they may readily he distinguished froi:i the young of the other spec- ies by. ISieir erteir^al sculpture. Oompared \7ith adults, the primary radials of young shells are prominent and the secondaries sunrress- ed, Guppy referred this form to £. pennaoea (Laraarck) or G, de- -A- cui'satus f Linnaeus), hut it obviously differs from the recent, which has been given either of those names, being raore conve" , v-lth fa. more irreg^alar conton.s and weaker concentric sculpture. Most of Gabb ' s Santo Domin~ian pennaoea are neither that s-oeciss or jamaioensis ; "Siey differ from the latter by being less inflated, more elongated transversely, without the posterior keel and trun- cation, the posterior -argln being rounde' more corfvexly than the anterior, with the pri-^ary radials slightly more prominent. In addition to this form, typical speciirens of jamaicensis are present. G. carbasina Bro^'ai and Pilsbry (l) of the Gatun faixna, is smalley, (1). Proc. Acad. ITat. 3ci., Philadelphia, vol. 55, pp. 563-564, pi. S8, fig. 9, 1911. vathout the posterior keel and truncatio;., with lov.'er, bro- der vm- bones, more prominent primary radials, more conspicuous concentric - 1C7. - sculpture, fewer ard coarser teeth, deeper and sharper internal marginal crenulations. Oeourrenoe,- Upper Oligocene.- S nto Domingo (Gahb, 1873; Guppy, 1874, 1876), ?Gumana, Venezuela (''uppy, 1874). Lo'"er Miocene: Bowden beds, Bov;den, Jamaica (Gu py, 1866, 1874; Dall, 1898) - 15^ (?LY3-:f]vTERIS AOUTIGOSTATA (SoY/erlDy) Pe c tunoulns a cut 1 o os tatiis Sowerby, 1850, Quart. Jou.r. Geol. Soc . Xondon, vol. 6, p. Sr^, pi. 10, fi;-^. 15. PeGturiouliis acut loo status Sowerby, Guppj-, 1866, Quart. Jour, Cieol, Soc. lona.on, vol. 22, p. 29?, 1866. .A:Kinea aoutieostata (Sowerby) Gabb, 1875, Trar.s. Am. Philos. Soc, new ser., vol. 15, -o. 255. Peot-'jmculus aoatioostatus Sowerby, Cuppy, 1874, Geol. Mag., Decade 2, vol. 1, p. 445 (olaeck list). Peotunoulus acixtiGostus Bowerby, Guppy, 1876, Quart. Jour. Geol. Soc. London, vol. 52, p. 552. Glyoymeris acutioostata (Sowerby) Bro^'-n and Pilsbry, 1911, Proe. Aoad. Hat. Soi., Philadelphia, vol. 65, p. 564. Description.- "Testa suborbicularis, suboblioua, postiee subangulata, radiatim mult i cost at a, costis tenuibus, sulclsque ang- ulatis, area cardinali bifariam tenuiter sulcata, dentibus csrdin- alibus ad ntrumque latus nunierosis, confertis." (Sowerby, 1850). Type locality.- Santo Domingo. Shell of mediinn size, the height about equaling the length, moderately convex:, outline ova'^e-trigonal ; dorsal margins scarcely differentiated; posteriorly produce 1, subangular; broadly rounded - IC' - anteriorlv and ventrally; umoones very low; external sculpture consisting of .abo^it twentj-'-six lov/^ radiating rilos, sharply anp-ular on imv/orn shells except in the extreme antero- and postero-dorsal rep-ions, the flanlcs of the rihs sloping gently from the angular sxinniit, forming angular interspaces; concentric sculpture of fine, equcally spaced striae, usiially not overriding the summits of the radials , hut Gonspicuo^^s on their flanks; cardinal area narrow, very short, not affecting the angular outline of the dorsad marpin, Gonsnicuously marlred hy ligament grooves diverging from a median vertical line; hinge plate decidedly arcuate; teeth small, numerous, the series interrupted by the subsidence of the cardinal area, with twelve or thirteen teeth on either side; inner margin of the valve coarsely and weakly erenulated. Dimensions.- Length, 24 mm.; alt. 25.8 mm.; semidiam., 6.5 w:.. Remarlts.- The beautifully sculptured shells of this widely distributed species are almost as nimierous as jamaicensis. The low, sharply angular ribs arjd subangular posterior yroduction are the salient characters. Among immature forms the irregular outline of the oosterior margin is poorly defined or entirely lost. Young shells apparently be!J.onging to this species, present puz-ling features. Some have the typical, somewhat compressed form and char- acteristic angular scul"Dtire; others are more inflated, with high- er umbones, angiilar or subangular ribs, separated by definite in- terspaces; another group, including most of the sm.alTest shells. - l(-6 - are inflated, with more or less rounded ribs separatef] by narrovrer interspaces. Tumbers of the la. st group somewhat resemble 0. peot- inata (Gmelin) (1), bxit differ by their higher umbones, narrower (1). Srst. ITat., p..l?lJ?, 1792. ribs and interspaces. G, canal is Brovna and Pilsbry (2), described from Gatun, (2). Proc. Acad, Hat. Sci., Philadelphia, vol. 63, p. 364, pi, 28, fi?. 10, 1911. Panama, is more inflated, v/ith rounde' ribs, v:h ch may, however, be subangular. Ocourrence.- Upper Oligooene.- Santo .Dominp-o (Sowerby, 1050; Gabb, 1873; Gup^y, 1874, 1876). Gumana, Venezuela (Guppy, 1874). Gatun formation, Panama fBro?m and Pilsbry, 1911). Lov/er i'^iocene : Bowden beds, ^x-ien, Jamaica. (GuDoy, 1874; 1875; Bsll, 1808). - 1G7 - GLYGY1.TEP.I3 PSITKAOaA (lamarck) Peotm'ioulus pennaoeus Lamarok, 1019, ibiirn. sans Vert., vol« 6, p. 51; 1835, idem, 2iid ed. , p. 430. ^eotnnc-'alTTS garolinianiis Oonrarl, 1855, 'F'os, Merl. Ter. IJ-nil;ed States, no. 1, inside of 'baek cover. Pectimoijlus carolioensis Conrad, 1340, idem, p. 65, pi. 55, fig. 2. Peot jnoxi-liis cerolinensis Conrad, 1841, Am. Joi:ir. Sci., Ist ser., vol. 41, T). 346. ?e3tunG:^li:!S pennaoeas Lamarclc, Reeve, 1815, Oonoh. Icon., vol. 1, Pectiinoiilus, lol. 5, fi??. 24. rot P. carol in ens is Holmes, 1860, Post-PleiOG. I''os. South Jarolina, p. 15, pi. 3, fig. 4. Azinea oarolinensis Donrad, 1863, Proc. Acad. I.'ct. oci., Phila- delphia, vol. 14, p. 580. Azinea cerolinensis Conrad, Meek, 1854, Mioc. Check List, Smiths. IvIiSG. Coll., no. 183, p. 5. Peottmoul^s lineatus 'P'eilprin, 1887, Trans. Vagner ^ree Inst. Sci., Philadelphia, vol. 1, p. 105. (non Lamarck, 1819, non Heeve, 1845). Glycymeris pennaceus (lamarck) jjall and Simpson, 1901, Bull. U. S. Pish Comm., vol. 20, ot. 1, p. 459. ITot P. pennacea Ouripj?^ 1866, Cahh, 1873 (ex narte) = G_. ja-iaiconsis Dall . - 168 - Description.- "P. testa orlDiculari, tunida, decuEsatim striata, alba; maonlis spadioeis lon-^itudinalibus fasciculatis; natibus lira- menti extrematate antica iiifleris." (Lamarck, 1819). The Bovi'den specimens are of rnediiun size, sifocircular , the height virtually equaling the length, decidedly convex; mnbones low, mixch inflated, opisthogyrate, placed slightly behind the median horizontal, almost in contact; anterior rlorsal marp-in longer than the posterior, -//ith a more gf-ntle slope to the lateral marrin; slightly produced posteriori;;, biit rounded; evenly roimde'^. anter- iorly and ventrallj; external surface sculptured v;ith twenty-four to thirty almost equally spaced -orir.ary radiating ribs, on young shells sharply defined and narrow throu.ghout, on adults most con- spicuous on the umbonal slopes, be comiiig very lov7 and relatively broad distally, broader than the interspaces, with a median or sub- melian groove on the clistal tv/o- thirds ; Secondary radials, extend- ing about four-fifths of the distance from the margin to the ujnbo, occasionally present; concentric sculpture of fine striae impress- ed on the radials, ;rodu.eing a cancellated effect; cardinal area narrow, deenly impressed, confined to the area immediately uiider and before the imbo ; hinge plate gently arched; teeth in tv;o series, the anterior conve-, including fifteen teeth, the five nearest the umbo vertical and small, the remainder coarser and tyx)ically glycy- meroid; posterior series shorter and less convex, \7ith nine rela- - 169 - tively coarse teeth, the first three (from the imho) angular, the remainder straight and almost horizontal; musaie scars relatively Isr-e, weaklT but^:ressed; inner margin of the valve ;7ith fine crenulations. Dimensions.- Len-th. 26 nim. ; alt.. 25.8 mn. ; semidiam., 9 nm,. This interesting ai-cymcris is represented by three right valves. The smallest form has radial soulpt^j-e which differs some- what from that of the largest, the Hbs being very sharply defined and subangular, beoomiiig slightly broader distally, with faint sec- ondaries in the distal portion of some of the interspaces. On the shell of intenr.ediate size the primary ribs are relatively broad and angular distally, with secondaries of almost the same order of magnitude. Finally, on the largest individual, the ribs are flat, broad and grooved, -rom the above It is quite obvious that -oung shells display to better advantage the characteristic can- cellation. The deeply immerse.'., .nlmo;-^t i-ternal ligament, pronounced backv/ard twisting of the umbo, the strikingly different anterior and Toosterior teeth are unusual for the genus. The largest Bow- den valve bears a remarkably close resemblance to a lar-er Jest Indian v Ive in the national I.aiseum collection. It should be remembered that lamarck (1855) stated that this spe-^ies is "re- marquable surtout par les crochets qui or.t leur pointe dirigde - 170 - toat-d-fait i 1 'extr^p/.lt§ aiitdrieure (posterior) du ligament, le mani^re que le lii^ament Ost enti^rement loas de 1 'intervalle qui les s^TDare." A parently it is not "iiovm v/hether such forms actn- all^" belong to the group w'niel- usua^^.lj? receives the nane oennaoea. members of 7/hich do not have the above hinge and ligament charac- ters; and besides have a more angular posterior narf?in, b^it the same sculpture. Oonrad reported one of these from the Duplin of I^orth Carolina, although it has not appeared in siibsequent collect- ions. Because of this uucertaintj' it is do'^btful' whether all of the above citations belong in the synon^raj?. G, jamaigensis is more inflated, more angularly produced and keeled nosteriorl^", •.vith less prominent concentric sculuture, a different cardinal area and hinge. Occurrence. - lower Miocene : Bowden be^s, Bowden, Jamaica. Miocene.- Duplin formation, ITorth Jaro" ' fJonra'^-, 18S5, etc.). Pliocene.- Dominica, llest Indes (Dall, 1808); Oaloosahatchie marl, Florida ( Jail , 1890). I'ecent.- Forth Carolina to the ■"est Indes and east to Bermuda. - 171 - Super family Pteriacea. Family Pinnidae. C-en\xs ^I"T'^A (linnaeus) lamarclc. PIIIIJA HE?U?;OA n. sp. Desori'Qtion,- '^hell small, slender, moderately thicic, strongly convex; summit of the shell subangular to roiir.ded, sit- uated nearer the dorsal margin; 'dorsal surface almost flat, the ventral gently arcuate; a^pex rounded; dorsal and ventral margins straight, diver?-ing at an angle of about 25°; external surface with a well-definec'., relatively deep sulcus, beginning near the anterior end and extending posteriorly along the sumniit of the shell; dorsal region of the shell sculptured with :^lve well-de- lined longitudinal rid^^;^, excluding the ridge adjacent to the sulcus; upper half or more of the ventral portion sculptured with three more irregular, broader, lower ridges, followed (toward the ventral margin) by oblinue, obscure iindulations, diverging slightly from the margin and terminating abruptly at the longi- tudinal rid'-es; inner surface v;ith a lov7, narrow ridge corres- ponding to the external auleus. Dimensions.- Length, about 65 ram.; max. alt., 17.5 mm.; max. semidiarr.., 7.8 mm. - 172 - ;^emar''S.- This species is desoribecl from two fragments, fae median portion of a rirht valve and an immature, almost oom.- plete left valve with the er-ctreme posterior re2;ion lacking. On the larp-er fragm.ent most of the posterior muscle scar is visible, showing that it is large, longitudinally elongate, converly round- ed posteriori;/, ventral in position. The principal features are the strong, asymmetrical converity, prominent e temal sulcus and the character of the sculpture. The Oaloosahatchie P. caloosagnsis Dall (1) is heavier, more (1). Trans. Wagner Free Inst. Sci., Philadelphia, vol. Z, -ot. 4, p. 550, pi. 26, fig. 4, 18X1. symmetrical, v/ith a broader, higher internal ridge and different sculptiire. P. rudis (Linnaeus) Dillwyn (2), a recenl; West Indian (2). Linnaeus, Syst. Kat., ed. 12, no. 1159, 1766, e:c parte; Dillwyn, 'Jat. Rec. Shells, p. 522, 1817; Reeve, Conch. Icon., Pinna, "ol. 10, fig, 19, 1858. species, is thinner, with a less conspicuous external sulcus and internal ridge and differs also in sculpture; the other recent '.Vest Indian form, P. carnea C-melin f^l, differs in a simi- iZ). Syst. llat., p. 3565, 1792; Reeve, Gonch. Icon., -inna. pi. 20, fig. 18, 1858 (as P. flahellun)) . 175 - lar manner. All of the above species reach a larfrer size than the Bowden form. Ocourrenoe.- Iov;er Miocene: Bowden -be^.s. Bovvden, Jamaica. - 174 - Genus ATSIITA Graj?. ATRTI^A sp. inflet. The genus Atrlrig.. is representeil b^/ a sinp-le fragmentary right valve. The ventral r.argln, apical and extreme posterior portions are missiug, so that the outline is uncertain, although it a -pears to be elongated and slender with the dorsal margin straight and slis-htly refle3?:e5, Most of the external surface is sculpture ' ''- relati"cli' coarse oblique ru.dulations upon v.hich are superimposed finer oblique markings; but along the ventral edge, \"hich may be some distance from the ventral margin, there are indications of at least one longitudinal ridge. BecaTise of the' character of the sculpture and the feeble convexity, this frag- ment is belipved to re'oresent a di s'':inc t s-oecies. OcG_rrence. - loTj^^r Miocene; B^wden beds, 3,o\vden, Jamaica. - 175 - PemilJ^ ::elinidae. Oeiiv.s IdlEA Hetzius, KillKA sp. indet. A small fragment of an apparently aclult valve and. an almost perfect, but very j-ouno;, valve are present. She larg-er is very thielc- shell ed in the iimhonal res-ion; the hyssal notch lono;, narrow, shariDly indented; the ligament grooves long, diverging at a slight angle from the hyssal notch, the raised intervals between the grooves narrov/"er than the grooves; external sculpture feeble, consisting of numerous fine concentric striations, reinforce"! a,t intervals by incrementals. Because of the decidedly narrov,' byssal notch this fragment has an unusual aiopearance. The other extremely small valve is subquadrate in outline; anterior lateral margin flexed inv/ard, bu.t without a definite byssal notch; ligament grooves relatively wide, four in number, separated by much nar- rower tidges. Occurrence.- Lower Miocene: Bowden he's, Sowden, Jamaica. - 17 6 - Jamily Pteriidae. Genus PTSRIA Scopoli. PTERIA PEEP0G2RA n. sp. Desoription.- Shell small, moderately and "broadly inflate^^ along a rlia°"onRj^ from the vimho to the postero-ventral marrin, the greatest oonverity meciial and rising a'bruptly from the anterior lateral margin, descending more gently posteriorly and ventrally; dorsal mar?-in m.oderately long, strrip-ht; umhones lov.', scarcely rising above the dorsal r:argin; anterior auricle small, triangular, depressed, set off from the rest of the shell hy a lei'ge along the line of the narrow hyssal sinus; srirface of the shell smooth ex- cept for obscure sinuous incrementals on the anterior auricle ; cardinal area very narrow, lorn'", extending almost to the extremi- ties of the forsrl mar^i-in; '■'in-e^ -^f right valve T7ith a soclcet placed slirhtly before the umbo and a lateral lamella near the posterior end of the dorsal mar?rin. Dimensions.- Length, about -'^ ^'ii^i. ; ■-'^'"., 11 nmi. ; seraidiam. , 5.2 mm, . He marks.- 2.* prep oc era is represented by two somev/hat frag- -"-entary ri ^-ht vs.lves. -he incom'oleter.ess of the posterior r^ortion of both valves le?:^ves some doubt as to the outli: c, biit it '-^ay be Judge -1 that the shell is not much produced along either the post- - 177 - ero-dorsal or postero-ventral mar-ins. Dall (1) refe " "^o this forra as Pteria inornata Gabb (2) (1). Trails, j'ag-ner Free Inst. 3ci., Phila^^ielnhia, vol. 3, pt. 4, p. 669, 189G. from Santo Domingo, '.'/hat is evidently? intende 1 to be the type of that species is a mould impressed on a hard gray liT.estone matrix, [Z], Trails. Am. Philos. Soc, new ser., vol. 15, p. 255, 1875. altogether ^iifferent in lithological e]3.racter from the remaining Santo DominjTO material, with little of the shell rem.aining; it is more convex, more produ.ced posteriorly, with the anterior auricle narrovjer and more acuminate. The 3hipola material whio' has been described as P. (ar--entea var.?) oh i pel ana Dall (l^) is very frag- mentary; apparently the forra is less nroduced posteriorly and more abru'otly inflated. (?). loc. ci^., -0. 669, 1838. Qgcurrenoc .--r^^p^ TTinr;pnfir Bov:den bR;'!s, Bov.'den, Jamaica (Dall, 1898). - 178 - Superfamily Ostracea. family Ostreidae. Genns OSTP.SA (Linnaeus) lamarck. 0ST3SA I.3;G0D0II Hanley. Ostrea megodon Zanley, 1845, Proc. 2ool. 3oc. London for 1845, p. 106. Ostrea gallus Yalenoiennes. 1846, Yoy. Yenus , Ooquille, pi. 21. Ostrea cerrosensls Gabb, 1869, Pal. California, vol. 2, pp. 55, 106, pi. 11, fig. 61. Ostrea galliis Yalenoiennes. Gabb, 1869, "^our. 3onch., vol* 5, p. 32. Ostrea raepodon. Hanley, P^eeve, 1871, Oonch., Icon., Ostrea, pi. 12, figs. 24a-b. Ostrea gallus Yslenciennes, Heilprin, in 'kTiite, 1884, Fourth Ann. -iept. U, 3. Geal. Stirver, p. 715. Ostrea me^odon Hanley, Dsll, 1898, Trans. ,7agner free Inst. Sci., Philadelphia, vol. ?, i^t. 4, pp. 685-686. Description.- "Ost. testa falcata, glabra, solida, subaequi- valvi, pallide livido-purpurascente , marslnis versus plicata; pli- ois anticis 5 aut 6, maxirais, subangxilatis ; posticis minimis, ang- - 17;^ - "alatis, pauois, sutiobsoletis : marglne valde plicato, intusque ma,'?is miniisve scabro; natibus incizrvatis; superficie interna albo- virescente, n-amquam mar^aritaeea; cicatrice satis magna, reniforrai. Long. 5 poll." "A rare and extraordiioarj- species, \?hiG]a hears not the slii-^ht- est resemblance to any of the recent Ostraea. '^he narrow sickle- shaped contour and .Gigantic marginal tooth-like foldo form its most distinctive character. '2he adult specimens are attached by their apices only." (HanDey, 1845). Shell small, thin, sub e qui valve; both valves compressed or slightly convex:; outline variable elongate and longitudinally sub- ovate to subfalcate; left valve bearing three to five broad, ir- regular, subangular to roui'.ded plications, most prominent at the ventral mar~in and extend only a short distance from the mars-in; denressions between the plications broader, t- inner and less ang- ular than the plications; right valve v.-ith similar, b;it less promi- nent, plications or more frequently irregularly warped; both valves Tvithout definite concentric sculpture except inconspicuous, usually non-laminated incremental lines; ligament area wide, oblique in pos- ition, with, on the left valve, a broad, shallow median depression; submargins finely, but conspicuously corrugated; muscle scar rela- tively large, posterior in position, longitudinally subellintical to broadly subovate in outline, with the anterior dorsal ir.ar-^in deeply em.arginated. - 180 - Dimensions.- A longitudinally sulDOvate right valve: lat. 86.5 nim. ; alt., 40.5 nm. A subfaloate right valve: dorsal lat., 17 mm.; ventral lat. 27.5 mni. ; alt., 31.5 mm. Remarks.- The proverbial difxioiilties iiivolved in the diff- erentiation of the members of this genus are augmented in the case of the Bo'.7den osisters by the almost complete absence of lar^re in- dividuals. The s-oeoimens referred to £. me go don are b:y far the most numerous. Typically this species is subfalcate, but most of the indivirluals are only slightly curved, '.iiile many of them have an o -.tline vvhich varies from longitudinally? elongate to lo2ig- ituciinally subovate ^ith the umbo placed at or near the posterior end. The most characteristic features are the small number of broad, subrounded, short plications on the left vr.lve, the similar sculpti^re or irregular warping of the right valve, and the absence of laminatei concentric sciilpture. The somev/hat falcate 0. 'oauci- Dlicata Uall (l), described from the Oak Grove s?.nd, has a larger (l). Trans. 'Vagner 7ree Inst. Sel . , Philadelphia, vol. ?, pt. 4, p. 578, 1398. 'As _0. sellaeiormis ^onrad vsr. pauoiplieata. ) . number of radials (seven to fifteen) and regular concentric lami- nae. !^on- falcate forms of megodon som.ev/hat resemble the v/idespread - 181 - 0. trig'onalis Go rad (l) of the same size, but tri pen alls is thick- er, with more definite oonoentric laminae and a wider ligament (1). Jonrad, i'. A., Proc. Acad. L-at. Sci., Philadelphia, vol. 7, p. 259, 1855. area. Gaht (2) suggested the ici entity of his 0, oerrosensis. from f2). loc. cit., p. 106. the L'io^ene (?) of Oerros Island, off Iov7er California, with the undescrihed , but figured, recent 0. "-alius Valenciennes, but stat- ed that cerrosensis is not more than half as large as the recent f or-- . He also noted the occxirrence of an oj-ster in the late Tertiary of Payta, '^eru, which he considered identical vath gallus; in fact, later in the sa'^ie year in the Journal of ^oncholop-y he called the Peruvian form p-al lus . Reeve apparently v;as the first to recognize the identity of .callus with the previou.sly described megodon. If the above synonymy is accepted, this species is, as Dall has stated, one of those forms which formerly v/as common to the Antillean and Pacific regions, but after the senaration of the tv.'o provinces persisted only on the Pacific side, ivamples of such distribution are frequently encourtere 1 , not only among - ]. the molluscs, biit also amoA? other groups, esoeciaily the eorals. OoGu.rrence.- Oligocene.- Santo Domingo (Dall, 1898^. lower Mioeene: Bowden beds, 'Bowden, Jamaica. (Dall, 1898). T'io- cene(?).- 3erros Island, off lov/er California ("aho, 1869; Dall, 1898). Post PlioceneC?).- Parto, Peru (Gahh, 1869). Post Pliocene (?).- San Bruno, east side of peninsula of Lower Oali- forni (Gahb, 1869). Recent.- Oulf of California at Acapiilco and southv-ard (Dall, 1898). OSTREA HAITEIISIS SowerlDy. Ostrea Haitensls Sowerbj-, 1850, 'iladelphia, vol. ?: , pt. 'r, o. 685. ?Ostrea aff. vespertina Conrad, Toula, 1908, J.,.hr'o. K.-k, (Jeol. HeiGhsanstalt, vol. 58, pp. 710-711, pis. 26, fig. 1; 2 3, fiffs. 14a- c. ?Os-^rea aff. ves^oertina Conrad, Toula, 1911, idem, vol. 6?, pp. 474-475, pi. 29, fis-s. la-b. ?Ostrea ^ratunensis Brown and Pilsbr , 1911, "roc. Aca''. LTat. Sci., Philadelphia, vol. 6-'^, p. :566, pi. £9, figs. 1, 2. Description.- "Testa oblonp-a, crassa, plicata, plieic paucis (senis ad septenis), magnis, undulatis, siibsonamosis, soiiamis non- niuii'rjnain subtiibuloKis ; limbo interno onuiino glebro." (Sowcrby, 1850) Type loealit;; .- Santo T^omingo. The -^owden specimens are small (not esicee'^ing 50 mm. across), thin or slightly thickened, compressed to slightly convex; outline - ] varying from lonp-itu.dina] I3? ovate to broadlj? ovate or even suTs- oirci^lar; left valve vrith five to seven strong-, narrow, usiially sharply angular plications, some arisiiig near the umbo anrl hecom- ingr -oroffressively prominent towarci the margin; secondary? plications oe :!asiona] ly int ercalater'i "between the primaries at the margin and iTxtenrling a short distance from the margin; interspaces between the plications deep and sharpl; angitlar; concentric sculpture of laminae, superimposed on the plications and m.ost prominent near the ventral mar-In; right valve almost smooth or bearing plications similar to those on the left; submargins usually corrugated; mus- cle scar, large for the size of the shell, sube^ liptical to s:b- circular in outline, posterior in position; inner margin of the valve at times bearinr minute pustules. Dimensions.- lat. 28 mm.; alt. .'?5 ram. Remar^'cE .- O.haitensis is represented by only a few small valves. This meager representation is probably not a certain indication of its role in the composition of the- fauna, br.t, since no lar?'e oysters of any species are present, it may be explained by the fortuitous circumstances of collection. It must be rem.era- bere'l, however, that con'^itions maj have been unfavorable for the prolific growth of oysters, since in none of the collections -^o which the writer has had access, are the m.embers of this genus prominent, either in size or in number. The adult Santo Domingian 18G - speciniens are of enormous size. In the Ohipola and Oak Grove faunas of Florida _0, haitcnsis is the most widely distributer! of the- oj'Sters and is also ore sent in the Shoal ?.iver famia. (1) Here it attains a larp-e size, reaching 10 or 12 cm. across. •'hen (1), '^-ardiier, -'t.-.A., Mssv compared with specimens from either Santo Dominp-o or j'lorida the Bov/den forms are very small indeed. In the case of the large Florida forms the Ouitline is more suhcircular, the plications more persistent toward the umbo and the concentric lamellae often sub- spino.re on the crests of the plications. This species is characterized by its subcircular or broadly ovate outline and stronp-, relatively regular, sharply angular pli- catinns. Tbese feat^ires rea^^ily distinguish it from the associat- ed 0, m.egodon. vliich is more elongate, typically subfaleate, v/ith broader, fev/er, weaker and less angular plications and without pro- minent concentric laminae. The Oligocene Antip-uan 0. antiruensis BroTTn (2) is heavier than the typical haitensis ; the ^olications. (2). Proc. Acad. Eat. Sci., Philadelphia, vol. 65, totd. 60?, 614, pis. 19, fiff. 17; 20, figs. 1, 5, 6, 1915. v/hen present, although of almost the same number, are divided into 107 - tvi'o groups, one of five and the other of two, hy a posterior broad depression and, si. ce the shell is heavy, the plications soaroely affect the margins; besides, the marsin r^f the left Vr^.lve is strong- ly upturned and the right vf;lve correspondingly reflexed. The small, thin, elegantly sculptured 3o';;den forms are scarcely com- parable 7.1th this passive species, but the typical large haiten-^ sis approaches it more closely. Brovm states that "at '.Tilloughly Bay [Antigua] a much larp-er species of oyster was observed, ;oer- haps 0. haitensis Sowerby." (l) 0. rtif^ifera Sail {?.) from the (1). idem, TO. 6^:^. (2). loe. cit. , p. 687, 1898, (as 0. sellaeform.is Oonrad, var. rne-ifera. Tampa silez and Ghipola horiR;ons never attains the size of haiten- sis and may be distinguished from the yomi^ of haitensis by the coarser ribbing in the right valve and the more exfoliate" 1am-.- ellae in the left. The Oak Grove 0. pauciplicata Dall (S) has a (?), idem, (as 0. sellaeformis Ooiirad, var. pauciplicata. more falcate outline and more regular concentric lamellae. vThen C^abb described the California faimas he v/as not acquainted .':s he - 138 - later stated, vrith Sowerby's brief desGription (l), but when he (1). ^oc. cit., p. 258, 1875. prepared the Santo Dominp-o memoir he recognized the identity of his £. yeatchii ft^pe localit37, 3erros IslancI, off lo'.ver Califor- nia and oconrring also at San Bruno on the east .side of the Penin- sula of Lower Oalifornia) and 0. haitensis. The California form, apparently is comparable in size and in other features to the larpe ?loridian and Santo Dorainp-ian specimens. Ball has added to the synonymy t'-p ^ir^^i^ured 0. heerraarjii -^onrad and 0. ves oertina Conrad, both originally describee! from "Carrizo Creek", California. Accor'i- ing to the excellent figures in the ITe-ican Boundary Report, the plications of ves -^ertina are not as high or as sharp as on the typi- cal haitensi£ and the out] ine is not as rounded, but these feati^res are probably due to inmaturity. It ap-oears that the California paleontologists still consider vesnertina, veatohii and heernanni distinct species, Guppy (1866) stated that he could not consider 0. haitensis distinct from 0. virginica Gmelin, but later (137G) he recognized the fact that they are sharply differentiated, '-^oula's "Ostrea aff. yespertina Conr." 1D09, Cratun, Panama, a^mears to be the young of haiteticio; his ICll citation ( Tehu8nter)ec , l.e^ico) refers to two sr.all, rather elongate right valves, with strong concentric mark- - 139 - ings y.fcieh prolDable also are ^"oung haitensis. Brc- " ''^llsbrj plaoe'i 'loi'.la's Gati^n form in the s^/nonj^my of a new s-^ecies, £, gat- tuie lis is, of -^vhieh yonng specimens refiemTDle haitenois . but \-;ith the plications less shax'p, while the aci.ult t^/pe has low, ron.nde'^ , sorae- vrhat irregular plications tha.t produce an a-opearance different from the typical haitensis. Qcourrence.- Upoer Olierocene.- j nto Domirgo (Sowerhy, 1850; Gabh, 1875; Gupo^, 1874, 1873); Ohipolaraarl, -lorida (Dall, 1308, Gardrier, I.Ies.); Oak Grove sand, Florida (Dall, 1898; Gardner, I.Iss.); Shoal Hiver marl, Florida (Gardner, Mss.); ?Gatun formation, Pan- ama (Tonla, 190^; Brown and Pilshr';, 1911); I-ox-er I'ioeene: Bowden beds, 3o',vden, Jam.ai3a (Guopy, 1866; Dall, 1898)^ ? Oliso- cene (?).- Tehuantepec, Mexico (Toula, 1911), Miocene (?).- Oer- ros Island, off lower California ( 3ahb , 1869); Jarrizo Greek, Jali- fornia (^onrad, IS'o, 1857); other localities in California (auc^- ores). Pliocene (?).- Hoker Canyon, near Fewhall, California, (English, 1914 fl) ). Post Pliocene (?).- ■-'an Bruno, east side (1). Univ. California ^ub. , Bull. De^ot. Geol., vol. 8, ^o. 203- 218, 19^4 (as 0^ veatchii ':abb) of the peninsula of Lov/er California (Gabb, 1869). - 190 - OSTRSA FOZrJi: linnaeiis^ Ostrea foliurn Linnaeus, 1758, Syst. Fat., el. 10, r.. 699. ^strea folvura Linnaeus , Bom, 17S0, Kvs . 2,-es. '- . .,,.st. ^d. h.t ving-nette, p. IS]. Ostrea ^roliTT^ etc., Jheninitz, 1785, Conch. Cab., vol. 8, p. 21, 13I. 71, flFs. 552-666. Ostrea limaeella etc., Jhermitz, 1785, idem, p. 61, -ol. 75, fi-. 686. Cstrea loliim Linnaeus, Gmelin, 1792, 3yst. ITat., toI. 6, p. 3334. Ostrea folium linnaeus, LamarGk, 1819, Anim. sans Vert., vol. 6, p. 211. Ostrra liniaoella Lamarck^ 1819, idem, p. 211. Ostrea rubella Lcmarok, 1819, idem ^. '"'' :*^. Ostrea erucella Lamarck, 1819, idem, 0. 211. Ostrea folium Lir^aeus, d'Orbio-nj;, 1845 (?) in de la •"'---a. Hist, phys., polit. et nrtur. .-^p I'lle de Cuci., . ulluaques, p. (Spanish ed); 1855, idem, (French e^), vol. 2, , pp. 365-366. Ostrea foliuni Tinnapiis -peve, 1871, -^-:^^.^. Icon., vol. 18, Ostrea, pi. 18, fi^rs. 40a-c. Ostrea Jrons leeve, 1871, :.riem., pi. 19, fi-s. 41a-e. (as of Linnaeus) Ostrea ^ristnts ^all an^l Ti-n.son, 1901, Sul^ . . . vish Comm., vol. 20, ot. 1, -. 464, (non Born, 1730). - 101 - Description,- "Shell rather thin, brown or ''ororTiish purple, adherinf f^o msjio-rovf's y>-^' elongated lobes '^-^ "?->'^ irr'(^-r v.oiye. up_ per yslve in the middle elevate'"! into a tiihe-shajpec rib, all the sides divergently? ribbel; ribs, roimded, smooth," (Reeve, 1071). The 'Sow den -"-"- referred to this species are sniall and thin- shelled; otitline variable, long-itudinallj? subovate to elongate and narrow; left valve usually more convex than the right; longi- tudinally swollen medially; mar^-^lns of the valvep ^r,,.i:^-'-,.-r^r^r -^-i-f-v fifteen to twenty sharp, usually sub-rounde^l plications oeooming smaller dorsally and e2:tendin!? only a short distance from the margin, the central portion of the shell almost smooth or bearing cnrved clasping spines; concentric sciilpture of inconspicuous incremental lines; lip-ament area small, flattened; muscle scars small, subellip- tical to subcircxilai iix outline, usually posterior in position; inner margin of the shell, or onlj portions of the mare-in, often bearing small pustules. Dimensions.- Tat. 1] mm. ; alt. , 34 mm, Remarks . - i'hese forms are the most puzzling of this unsatis- factory assemblage of oysters. They cannot be separated from the recent ''/est Indian group which has been reported under varioiis names,- C. folium Linnaeus, 0. cristata Born and 0. narasitica Jmelin, Since this soecies has n^t been recorded in the Tertiary - 192 - and since the BoT^den fornis so closely resemble t'^e recent ones it is natural to acoe'Qt with some hesitanoi^ this ., -. ^en, pronouji- cei extension of range. 3}he s\zg~estion has "been made that these S">oeci-'-'.ens are recent shells which have been washer" n>o on the heach v/here the Borden he^^s are exposed, hut such a view uan hardl;,- be entertained since in color and te'ture these oysters are similar to the other Boc^den shells. It is extremely doubtf^il whether this s;pecies is genetlQally valid, since it may merely include forms which are abnormal because of situs. The Bowden forms, howcvr.r, are constant in the "oof'sess- ion of numberous, small, but sharp, marr-inal plications. The pli- cations of haitensis are lar^-er, sharper, fewer in number and ex- tend ^urtVer tovrard the nmbo, -.vhile the folds on me^'0^0j\ ere "ewer and broader; besides, foliian is more elongate than haitensis. of the sane size and narrower and m.ore cojivex thsji the non- falcate forms of me^ndTfi. The claspirjg processes were devel nop ' n. " ' r the "^ was attached, r>resumably to a root or so::.e other object, li':e the recent forms. In general the elongate, usually swollen form : " • -;ipr-iiif' -r-ivc-i-ftpi -^lications characterize ■^hiR f^nf^nVs 8.S here considered. 0. frons is placed in synonymy, although its pli is are acxTtely angular and th^^ r^-ell is usually e -^j^'^1'"='1- ,^ to nr—n* .-;,-• . .ansrck'fj "- •■ ... 'ed shells. - 195 - 0. paras ities. Trmelin (l), an African form, is less elon^f^ated, vatl n (1). Syst. i:at., vol. 6, p. 5336, 179S; lleeve, Oonch. Icon., Ostrea. pi. T, fig. % 1870. fewer plications that extend fiirther uuwoj.-d the njiiho. 'Bom's 0, cristata (2) is much broader, v/ith fewer and broader marginal ("). loc. ait., p. IIP, pi. 7, fig. ,'3, 1870. plications. Ainor.pr Gabb's Santo Domingian o^.sters are so ^"' "^ ^ornis v;hich probably should be referred to this species, althoiagh they are less elongate'i, with fewer lolieations that extend further toward the umbo and poorly develop^, ' olaspers. It iiia; be assLuned that ."'-.'i')b had these forms in raind when he noted the occurrence of "two or T)erhaps three other species of small orsters, amon,? which one appears to be t]':e coniraon mangrove oyster, _u. irons I. (lima- oella lam. ) " ( 3 ) . (r), Trens. Am. Philos. Soc, new ser. , vol. 15, p. 258. Occurrence.- Lower Miocene: Bowden he's, Bowden, Jamaica, decent: \7est Indies in shallow wate.-. - Ij; - Superfaraily Pectinacea. Family Pectinidae. Genus PEG TSN Kttll e r . S^^■bgemlS Peeten s. s. Section Peeten s. s. PS^TEIT fP2GTElO BAI^IiETTI n. sp. Peeten (Peoten) soror :}all, 1898, Trans. Wagner Free Inst. 3ci., Philadelphia, vol. 5, pt. 4, p. 712 (ex "oarte, non Gabb, 1875). Description.- '^hell large, sizbequilateral ; doreal margins long, slightly ooncffYe, diverging at an angle of about 95°; right valve decidedly convex, sculptured with nineteen to tv/enty-two strong, high, almost square, radial ribs, their e'lges and tops be- ing sli-htly rounded, separated by narrower, deeply chfinnelled interspaces; in the interspaces and on the flanks of the ribs ob- scure, fine slightly raise-"; concentric lines r^resent; left valve slightly concave, v/ith the same number of narrower, strong, square radial ribs, v/ith dr^ep, flat interspaces of the sarae mdth or slip-ht- ly v:i''ler; concentric lines mire irominent thfsn on the right valve and oc^easionally extending ocross the ribs, but less conspicuous on the ribs than in the intersoaces; submargins without radial - 195 - sculpture, relatively vade and forming a steep ledge on the left valve; auricles subeqnal, v;ith weak radial ribs and fine concentric lines; interior ventral marc'in deeply orentxlatea. ■Dimensions,- Left valve.- Lat. 50r:;m. ; al-^., 45 mm.; length of hinge, 25 mm.; Ii-nmature right valve.- Lat., 52 ram.; alt., 29,5 nui. ; diam. 7 "vm.; length of hinge aboixt 1!3 tmh. Remarks . - On the left valve the strong radial rihhing does not terminate abruptly dorsally, the large ribs being followe*^ by a few, weaker, closer radials, ?/hich gradually become obsolete leaving the subm.arrins without radial sculpture. The dorsal m.ar- -ins on the single m.ature left valve are proportionately shorter than on the younger ones and more concave, ~hile the fine concen- tric lines on the disk are not as prominent. ^'^■^.. ~ right valves are proportionately less convex, vath lov/er and narrower ribs and strone-er concentric sc ulpture which overrides the ribs. P. barretti is r ecor-nize'"' o^- its very convex right valve, v/ith strong, almost square radial ribs and slightly concave left valve, ?/ith equa"'ly strong, biit narrower anci square radials. It has been confused with P. soror (nabb) (1) , described from Santo L'omingo (1). Trans. Amer. Philos, Soc, newser., vol. 15, v. 257, 1^73, (as Jsnira soror). - 13: and later reported from Gatuii (1). -hat species '-as, however, more concave dorsal nar^-ins anf! v:ider auricles; left vslve with. (1). Oahh, ./. M. , Jour. Acad. Kat, Sci., Philadelphia, 2nd ser., vol. 8, p. .'547, 1881, fas Janira soror). slightly hroader and rounded rihs, narrower interspaces an-1 coars- er concentric sculpture v;hich overrides the rihs, the ''.epreasions on the inner marrin ?-/ider and the edges of the elevations more sharp- ly raised; right valve with rihs more rounded and auricles without radials. ^he Gatun P. relic n.us 3ro-;7n and Pilshry (2) has more angular rihs, vrith the concentric lines on the left valve slightly (2). Proc. Acad, ilat . Sci., Philadelphia, vol. 64, pp. 510-511, pi. 23, fiff. 3, 1912. ( -Pecten sp. (vielleicht n. so.) Toula, 1908.) vieaker, "but on the right stronger. This species is named in memory of Ivlr. Lucas Barrett, the Dir- ector of the early Jamaican Survey, whose premature death was large- ly responsible for the hopeless incoordination of the published results of that organization's investigation. Occurrence.- lower Miocene: Bowden beds, "Bowden Jamaica (Ball, 1898). - 137 - Section Euvola Dall . PEGTEIT (EUVOIA) BOV/DEITEITSIS Dall. PeGten f Uuvola) bov;'denensis Dall, 1893, Trans. '.Vagner Free Inst. Sci., Philadelphia, vol. 3, pt. 1, p. 715, -pi. 29, fip;. 1. ? Peoten (Eiivola^ b--r;rlenensis Dall. B6sr, 1905, Bol. 3oo. Geol. mexicana, vol. 1, p. 145, (oheck list]. ? Pecten (Euvola) "bo-.vdenensis Dall, BBse, 1905, Bol. Inst, s-eol. mexico, no. 22, p. 27, pi. 1, figs. "3, 10. Description.- "3hell resembling P. ziezao L. in the right valve, T;ith about twenty- three obsolete snioo''"h ribs separated by inipres^:ed lines; right valve very convex; ears snbeqnal, s-iiooth, notch narrow, deep; left velve v/ith seventeen low, rounded ribs sep- arateil by rider, squarely impressed Interspaces; subrnargins wide, smooth; disk mof^erptely concave; ears subeoual, smooth, conccvely arched; interior margin of the bsse with pairei lirse, the pairs seiDaratefi by deeper chan" els ; cardijoal ui'iira obvious. Alt. 45, let. , 44.5 mm." "The SG^il-oture of the ]eft valve definitely seriarates this species from the young of ?. zicz^c . ?. me'^ius and allie"^ forms kno'A-n from this region." (Dai:!, 1808), Type locality.- Bowden, Jamaica. - 193 Shell thin, width and. length almost equal, hinfe line aporoxi- nately equp.l to half the width of the shell; dorsal marp-invS Ion?, slightly conoave, diverging" at an angle of about 105°; ventral half of the outline forming an evenly ser.icirculQr ; on the very convex right valve the radial lines hetv/een the obsolete "ribs" but feebly iraoressed, the surface more or less polished, with very faint, ir- regularly space' incremental lines, usually slightly more conspi- cuous and more regularly dispose! on the submarrins and on certain irregiiler, somev7?:at worn areas on the disk; the concave left valve ■•:ith the umbonal portion almost smooth, the intfrsoaces between the low ribs usually slightly raised medially; the conoentric fine lines more conspicuous than on the right, though still faint, and ■:iore regularly spaced; auricles on both valves subequal an-^ smooth, except for fine incremental lines, the lines decidedly -inuous on the right anterior a-^iricle; on the interior of the left vslve the ■laired lirae visible for only a short distanse from, the mar~in, "-:e interval between the two members of a oair more deeply channel- led than the interval between two pairs, the onoosite of the condi- "^ion on the right valve, with lirae extending further up toward the vimbo. 'Dimensions.- A right valve.- lat.* 44 mm.; alt., 45 mm.; 'Ian;., 15 mm.; length of hinge, 21 mm. A left valve.- lat., 47 ^::m. ; alt., 46. S m .; :''iam. , 6 mm.; length of hinn-e, 22.5 mni. - 199 Renarks.- The almost smooth, very convex right valves and moderately concave, relatively strono-ly sculptured left valves of this species are conspicuous among the 3owden scallops. The rihs on young left valves are weaker and iiarrovier than on adults. P. "bovrdenensis is closely related to the recent ]^, ziczao Linnaeiis (1), hut the riprht valve of the recent form is not q^^ite as convex and the left valve is s';ulptured vjith more numerous rihs, separated hy narrow impressed lines. P. medius Lamarck (?) is (1). Syst. i-at., ed. 10, p. 695, 1753; Heeve, Conch. Icon, vol. 8, Pecten. pi. 6. fig. 29, 1852. more strongly rihhed. The Oosta xiican Pliocene P. limonensis Dall (5) is smaller, ~:ith less poorly defined rihs on hoth valves, (2). Anim. sans Yert,, vol. 6, p. 16,?, 1819; Ohemjiits, Jonch. Oah., vol. 7, pi. 60, figs. 585, 587, 589, 1784. (5). loc. Git., p. 717., 1898, ( = Janira laevi-^ata Gabb. Jour. Acad. Kat. Sci., Philadelphia, 2nd ser., vol. 0, p. 579 pi. 47, fie-. 84, 1881, not P. laevi^atus Goldfxiss, 18?5) Trie left valves which Bttse described from the '^liocene of Tttxteoec, I'exico may be bowdenensis. biit the interspaces seem to be too flat and deep for that species. OGCu,rrence .- Louer I.Iiocene: Bowden beds, 3ov/den, Jamaica (Dall, 1898). Pliocene.- Tuxteoec, T'exico (39.se, 1905, 3 906). PEGTEN (EUVOIA) sp. indet. The presence of a second species of the section Euvola is indieatei hj fx-agnients of a small right valve. ^'hc shell is very thin, feeblj- convex; exterior surface sc-aptured with about twenty- five very weak, rounded radials, obsolete toward the umbo, separat- ed by flattened interspaces about half as v/ide; concentrio increr.en- tals fairly prominent; interior of the valve with v;eak radials of about the sane order of magnitude as the external ones. Sxterzially this form is very ciose to P. gatimezisis Toula (l), but comparison mth material in the Philadelvohia Academy collection (1). Jahrb. Z.-k. geol. -^eichsanstal t, vol. 58, up. 711-712, pi. 26, fig. 2, 190S (Hot P. (Amunjiym) ^atunensis "^oula, idem, pp. 716-717, -ol. 26, fis. 10). from the Gatun beds shov;s that the Gatun species has external rad- ials that are slightly higher toward the ventral marp:in and inter- nally the interspaces between the radials are narrower ur.til near the margin where they suddenly become -rider and deeper, the ribs therefore becoming narrower and hip-her. It is possible, however, that these differences are due t^ the difference in characters of various growth periods, only fragments of larpe valves of p-atunen- sis being available. "^he B-^wden form is separate^! from the associate'' bowdenensis by its less conve : contour, the presence of flattened interspaces n _ between the external raclials and of internal radial ribs instead of rsaired lirae. - Occurrenoe .- lovrer riocene: Bowden beds, Bo?/den, Jamaioa. - 202 Subgenus 0Tilara3?s Bolt en. Seotion Ohlaraj?s s. s. PSGTEK (CKLAI^YS) TAGIIJUIUS Jail. Peoten / Ohlsm-'S ) ornatus lamarclc ? vfv. va?inulus Dall, 1893, Trans, ./agner ?ree Inst, ^ici., "'hilac'elphia, vol. 5, pt. 4, pp. 715-716. ? Peoten sp. (aff. P. gracilis Sov/. ' Toula, 1908, Jabrb . V. \. geol. Reiclis., vol. 58, p. 711, pi. :'o, -^i^- . 7. SesorLption.- "Seven small valves of a s'oecies closely resem- bling ^, ornatus v/ere obtained at Bowden; the form and sculpture are practically the same, but the ribs (twenty-one to twenty- five) are single, subequal, and not fasciculated, and are separated by simple narrower interspaces not radially threaded. The young of oK'^atus. as far as observed, seem to always have one or more inter- stitial riblets. I therefore propose for the present form the varietal name of vaginulus, which may be raiser! to specific rank if the difference is confirmed by the characters of ad'ilt specimens." ( Call, 1893). Type locality.- Bow den, Jamaica. Shell small, thin, subeqtti valve, suborbicnlar, the height slightly e-ceeding the width, equilateral, erceptirig the auricles. - 203 - moderately inflated; right valve usually less inflated than the left; dorsal margins divor-ing at an angle of 90° or less; both valves sculptured with tv/ent^; to twenty-five slender, square to suhroundFil radial ribs, se-of^rated "bj rsrv^vier interspaces; in the interspanes and ocoasionally overridi.vg the ribs fine, inconspicu- ous, slightly raised concentric lines present, rarely causing a few anterior anri nosterior ribs to be scabrous; subniarglns v;ithout radial sciiLpture or v/ith fine radiels, f ormiiig a continuous series with those on the r!isk; hinge long, auricles decidedly uiiequal, esoecially on the ri?ht valve; byssal notch deep and sharply sinu- ate I; both auricles sculptured with irregular radial ribs and con- centric lines,, the sculpture of the anterior auricle coarser and more decidedly imbricated. Dimensions.- A right valve: 1st. 11. 8 mm.; alt., 1? mm.; diam,, 1. 9 ram.; length of hinge, 7. 5 mm. A left valve: lat. 12 nim. ; alt., 1^. mm..; ''iam. 2.1 mm.; length of hinge, 7.2 mjn. Hema rk s . - The small, thin, delicately sculpturet^ valves of this species are very abundant and the individuals range in stages of gro77th from mature to very yoking. This abundance and the con- stancy of '"he above note1, marked differences between it and the recent P. omatus Lamarck (l) testify to the advisibility of rais- (ll. Anim. sans Vert., vol. 5, p. 176, 1819; Bruguidre, .:nc. H4thod, pi. 214. fig. 5, 1739. - 204 - ing Dall's varietal nanie to ST:eeific rsnlc. The outline of the shell is soraev/hat variable, some of the shells being more orbi- ciilar than the tyi-^ical slightly elongate form. On some valves the anterior submarrin is narrower than the posterior and is with- out radial sciilpture, while on the posterior one radial sculpture ma^" or may not be present. Tn general, this species is charac- terized by its small, thin shell, suborbicular and moderately in- flated outline and nujnerous, finely sculptured ribs. Immature right valves are especially conspicuous because of their compress- ion and unusually long anterior auricles. The few inriividiials with rounde" ribs ajid slightly scabrous anterior anrl posterior rib£> dif- fer from the yomag of the asso:7ia.ter" p. ( AequiTjecten) sumpleus n. sp. of the same size by having more numerous and more slender ribs, narrower interspaces, with at no tire all the ribs scabrous. Toula's figure reproduces an incom.plete right valve v^'hich agrees, as far as the figure is concerned, v/ith vaginulus . He notes, however, that the ribs display a tendency to berjome f^icho- tomous on the middle of the disk. Since his material furnished only two fragmentary valves it is difficult to determine whether his form is icientical. Occiirrer.ee .- Upper Oligocene : ? Gatun, Panama (To^ila, 1908), Lower Miocene: 3owden he's, Bowden, Jamaica, (Dall, 1898). - 205 - PEOTEIT (GHLAJnS) AlvIEIiiUS n. sp. "Jescript iOii.- Shell small, siilDequivalve , suborliioular, the height and v/idth virtually equal, well inflate'!, the two valves equally inflated; the dorsal half, etoluding the a^.rieles, forming a sector of rhout 95'-*, the ventral half evenlj? suhcircular ; "both valvf^s sculptured with twenty-one to twenty-three strong, suhround- ed radial rihs, separate^ by narrower interspaces; concentric sculp- ture of fine raised lines usually appearing in the interspaces and occasionall;: on the rihs ; suhmrir^ins without radial, sculptu.re; auri- cles uviecu-~l, hoth hearing inconspiciioua radials, on the posterior auricle more prominent vei-trally, hut on the anterior broader and stronger dorsally, overriden by fine conc;entriclines, coarser and more irregular on the anterior auricle. Dif.'.ensions.- '. right valve: ":t., 15 mm.; alt., 14.8 mr.i. ; diam. , ?.? ram.; length of >ii!=3-e, ^ r-m. A left valve: lat., 1^'.5 ram.; alt., IS. 2 mm.; ^iara. , 5.5 ram.; length of hinge, G.2 ram. Hemar>s.- P. an: el e us is well represented, althouf^h indivi- diials are not as numerous as those of the other member of this section. '2he characters are constant except for a slight vari- ation in outline which causes some specimens to be slightly less rounded then the typical form. G'^'-^'-^^ionally a slight sulcus ap- pears on the extreme distal portion of the ribs, but this is a min- 106 or feature, never affeotin.p- all the ri"bs. This species is reeoprni- zed "bj' its '.veil inflated, si^-borhicular outline and numerous strong, subroiinded rat^ials. It is closelj' relatea to P. vaginulus "biit is slightly larger, more inflatei, with the right valve inflated to the same degree as the left, more rou'de'^, itB rihs are hroader and never as flat as those of many soeaiens of vaginulus. Al- though end members of the two series approach each other in oxit- line or in the degree of inflation, the^; may he separated hj? one or more of the above 'differences. I-imature individuals of the two species resemble each other very closely, but usually the ensem.ble 0 ■ the charaoters is surficient to differentiate them. Ocourren/. .- lower I.Iiocene: Bov^den beds, Bo^vden, Jamaica. - 207 - PEGTEII (JKLAir/S) Ij"EA1,:01"IPKU3 n. sp. Description.- Shell anall, thin, moderately? inflated, higher than v;ide, the dorsal marsrins slor)i:'" steeply?; e-- ternal surface soulptirred vrith about t\7enty-three narrovv, prominent, rounded, un- equally spaced radial rihs of inconstant width, some extending only, a little more than half of the distance to the ixmbo and all ■becoming obsolete before the u.mbo is reached; the ribs finely/ nod- ulated along irregularly spaced concentric lines; auricles unenual, with relatively prominent ra-'iisls roughened by overriding concen- tric lines; byssal notch prominent. Dimensions.- lat. 4 mm.; alt., 5 mm.; diam., .5 mm. Remarlcs.- "^Ithough the single right valve on vvhich this species is based is doubtless very young, the narrow, irregularly spaced and nodulated radials definitely distinguish it from the other mem.bers of the section. OoQurrenoe*- j^or/er Iliocene: Bo\"den beds, Bowderi, Jamaica. - 200 - PEGTEK ( CnlillvIYS ) 3SLIIPIGTU3 n. sp. Description.- Shell small, thin, compressed, the height slip-ht- ly exceeding the width; dorsal marrrins long; external scttlpture of eleven feehle, romided rios, L;eparated b^- v/ider interspaces, becom- ing obsolete on tbe dorsal half of the shell; concentric sculptiire of fine, microscopic concentric striae over the entire snrf ace ; aur- icles siibequal , the right anterior sciilptured vrith radials, with superimposed concentric lines, scabrous along the hinge; byssal notch prominent; interior of the valve with broad rndial unriiilations cor- respondirig to the external intercostal spaces. Dimensions.- lat. 7 mm.; alt., 7.5 mm. Tie marte . - -i-'his s-pecies also is re'orenentert by a small right valve. It is distinguished by its fev;, feeble ra dials and fine con- Tentilc striae. Dall (l) has described a closely related form, ?, alumensis , from the Ohipola ; it has more numerous and more promi- nent raciials. (1). Trans. V^agner Free Iiist. Sci., Philadelphia, vol. 5, pt. 4, p. 740, pi. 34, figs. 10, 11, 1898. Ocourrenoe.- Lower Miocene: Bow den beds, Bowden, Jrmaica Section Aequipeoten Fisoher. PEOTEII (AEQUIPIGTE:") IlLyiQU/J.! S Sowerl3j^ vcr. AjUJI:?I0TU3 n. var. Peoten Inaequalis juppy, 18C6, Quart, Jour. Geol. 3oc. london, vol- 2S, p. ?94, pi. 18, fi<-. G {non ^ov/eroy, I'^oO). Peoten inaeqixalis Guppy, 1874, Geol, Mag., decacle 2, vol. 1, p. 44-5 (check list), e:: 't arte , non Sowerljy, 1850. Pecten ( Aeguipe oten) iaa. ecm.alis .i^all, 1898, 'i]rans. ./agner Pree Inst, Sci., Philadelphia, vol. 5, pt . 4, p. 714, (ex parte, non Sov/erhj', 1850). Description,- "^hell of me'i ^ , the, height and width almost erm.al, suhequilateral, with the posterior side raore produced; right valve deoiderily inflated, left vplve moderately or slight- ly inflate", compressed toward th^ ':rsl nB,r~in; dorsal margins straight or slightly conerv?, •^'■-e -^^sterior raarrin long-^r ^-^^' --i+^h a steeper slope than the anterior, the two margin " ' . rging at an angle of 90°; exterior surface of right valve sculptured with seven- teen or eighteen high, hroad, more or less polished radial ribs, their tops slightly rounded and their flanlrs excavated; intervening intercostal S"oaces narrower, deeply and squarely chpnnele''; in the interspaces fine, but distinct raised concentric liixes present. -PJC the ribs imo -.tel, but at their disbnl ends irregularly spaced, arched incremental lines usually; visible; left valve with the sa-iie number o'^ ribs, b^it lovrer, .,._e rounded and -nf.h q t n -i^ 1 v. o- si'les dis- tally, the interspaces \7ider; the concentric lines in the inter- s^^aces snd the growth lines on Hie ribs more prominent than on the Tigh^' v-ivp; r:'ubma.rgins on both valves smooth, exoe"ot for ver- fine GOiicentric lines; auricles subequal, the po sterior vj'ith two to five small radial ribs, decreasing- in prominence from the mar- gin of the di sir or absent on the dorsal -oortion, ':he entire sur- face covered with fine concentric lines; anterior auricle seulp- txired with three to five usually slightly coarser ribc of irregiil- ar vildth, slightly rourhened by the over-riding, inconspicuous con- centric lines; cardinal crura prominent; interior ventral margin deeply crenulated, with lira'"' extending toward the imbo. Dimensions ,- A right Valve: lat., 25.6 m"'.; pit., 5^5.5 mm.; diam. , 8 mm.; length of hirjge, 13 mm. A left valve: lat., 26.5 mm.; alt., 25.8 ram,; diam., 5.S mm.; length of hinge, 14 mm. HeriB, r^-^s.- ' This form is by far the most ab^^' -■''^■^t of the Borden Pectens. ^lae right valve is much inflated, whi" ■ left is less convex or even compressi , 3 eeially among young indiviiiuals. ■''he degree of inflation of both valves is subject to slight vari- ation; the most inflated forms are also less orbicular, being high- er than wide. The difference in the character of the radial sculp- « • - 211 - tn.re on the -<'''^ Tr.-iyo.q ip ^-.n^'-pri. On the left valve, since the interspaces are v/ider than on tL.e rif;^ht, the cone entrio sculpture is more lorominent and the arched, cro?;ded growth lines on the rihs are more Gonstantlj^ -o^ ^..^ ...it . Left valves are usually more inequi- lateral than right ones. The rihs of immature left valves are less rounded, almost square, distally than on adults; while young right valves differ from adults in having the ^^■'-■: i'^-,- --r and the interspaces wider. The strongly inflated right valves, with hirh, "broad, sharp- ly chiseled rihs and the decidedly less convex left valves, with lower, more rounded rihs are readily distinguishable from the assoc- iated Pectens. The Gatun F. le vice status Toula (l) reaches a lar;?- P.l 7 ize, is loR':- -^onvex, v/ith more numerous (twenty-one), slightly (1). Jahrh. K.-k. s-eol. Heichsanstalt, vol. 58, p. 71?, pi. 26, figs. 4-6, 1908. narrov/er andlov/er radialc. Right valves may be confused with the young of P. operc:-lariforrais Toula (£), from the same locality, but {2). If^em, :ji;. 712-715, pi. "■, n~. 7.. the C-atun form is less inflated, ^:ri. th more nuraerous (twenty-five) narrower radial s, narrower and shallov,-: r interspaces; since the - 215 - left valve is about ss much inflated as the rin-ht it is r' ri'TM.e'ilj/ differeiit from the left valve of the Bov/den form. i'he roce.it P. !:iayapi;sensis Dall and Simpson (1) closely resemhles the yoii-ig of (1). Bull. U. S. ?ish Comm., vol. 20, -ot. 1, ■). 4o5, pi. 55, figs, V-T, 1901. aoutiniot^is in outline and sculpture, hut the rihs are lov;er and not quite as soiiare. It was surpris in?^ to discover that the Santo ;Ooraii\!?ian form differs from the inaecualis from 3ov;den and other Antillean loc- alities. Apparently the 1 -r-.-^-ftS'^^-^hl i nhfMl oorioe-ot '^f inaec^imli s was hased on Guppy's figure, v/nich, it m^.st be remembered, repres- ents a Jamaican, nreseumahly 3o"'den, foim, and on Cur ' jpeeimens, In the case of this species, as with Sowerhy'vS otn.-^r -m-^-' -"^iired spe- cies, it is assiuned that (?abb's Santo Domins-ian foi-ms are the same as those v/hich Sowerhy described imless they obviously ~' ""^r from Sowerby's diagnosis, altT- -^--^-h '-h^t ascumption may be incorrect; at least, it seems advisable to liiiit Sowerby's names to Santo Domin- gian forms v/henevor closely related, but different, species occur elsewhere. ' The typical inaecualis, -^s h.ere restricted, reaches a larger sise than its Bowden variety and although left valves are virtiaal"'-y identical in a-roearance, the rib'o of rir-ht valves are lower, more rounder^, v.l thout the flat tops liiid e.:c'-'avate '. flanl-rs - r.is - that are so chars.oteristi t? of the variety. In this connection it is well to reiiifc'iiioer that 3ov;erby desorihed (l) both ribfe -^.j in- terspaces of whst certainly was a rijht valve f. '.imclatiis" . (l). r^^uart. JoLir. J-eol. 3oe, Lonoon, vol. G, o. 52, lo"~. Ocaurrence_. - Upper Oligocene : Jturacao (Dall, 1898); Isthnius of Darien (Dall, 1898); lower I.'iiocene : Bovjden beris,. Bov/den, Jam- aica (C-npT)^-, 1866, 1874; Ball, 1898). P2GTEII {A20.UIPEGTBIT) SUlvIPLSUS n. sp. Peoten exasre ratus Crupnj-, 18G6, luart. Jour. Geol. 3oc. london, vol. 32, p. 294 (non Sowerby, 1843). Peotfin oxygonn.m "abo, 187r^, i'rans . Am, Philos. Doc, new ser., vol. 15, p. 256, (non Sowerby, 1850). Peoten exasneratus Cupoy, 1874, Geol. Mag. Decade 2, vol. 1, p. 443 (check list), ex -oarte, non Sar.-erb3", 1845. Pecten oxyironiis Guppy,"1874, idem, (non Sowerby, 1850). Pecten ox-;,g-oniim Guppy, 1875, Quart. Jour. Geol. Soc. Lonc^on, vol. 32, p. 532, (non 3owerby, 1850). Pecten ( Ae-ui-pe oten] thetidis Dall, 1898, Trans, //agner ?ree Inst. 3ci., Philadelphia, vol. 3, pt. 4, pp. 714-715, (non Sowerby, 1850). Uot P. oxygonuDi Sowerbj', Dall, l.!98, idem, pp. 713-714. Pecten ( Aeguipecten) ox yp: onijm Brown, 1913, Proc. Acad, i'at. 3c i., Philadelphia, vol. 5 5, p. 501. Description.- Shell of mefiium size, equilateral, except for the aiiricles, subenui valve, both valves moderately convex, suborbi- cular, v/ith the height and width virtiially equal; oixtline, exclus- ive of the auricles, forming a sector of a-o-^roximately 90°; hi^ee straight, about two- thirds of the vfidth of the shell; dorsal mar- gins stra.ight, their distal ends more roiuided on the left v:lve than on the right; external SGul^ture siinilar on hoth wives, v/ith eighteen to tv/enty prominent rarHal ribs, more or less square on the dorsal half of the shell, broader and more roimded on the ven- tral half, separated bj; narrower interspaces; the ribs and inter- spaces in the ventral half of the shell orna.'.ented v/ith radial rovifs of short, blmit scales, smaller in the interspaces, inconsni- Giious on the dorsal half, reduced to a single row and often ab- sent in the interspaces; submargins so-Jlptured v/ith fine, narrov;, irregularly spaced, squamose radid ribs; auricles broad, the ant- erior longer, with a deep byssal notch, both sculptured v;ith squam- ose radial ribs of irregular width, wider and higher than those on the submargins, on the anterior auricle the ribs wider and the scales more prominent than on the posterior; interior of the shell with paired lirae separa ed by e;:cavated intervals. ■Pi" ens ions.- A right valve: lat., 7A.5 ram.; al"^., ?4.'!r mm.; diam., 3 mm.; length of hinge, ?3.5 mm. -^ left v«lv8 : lat., 35.2 mm.; alt., '^4 mm.; "liam., 8.8 vm.; length of hinge, 24.5 mm. Bemarks . - P. sumple "-S is a coraTion form in the "Bowder; fauna and is one of the most wide-spread of the mid-Tertiary Pectens in the Oaribbean region, having been reported under various names from almost all localities where deposits of that age h:^ve been explored. ■'^'he characters are fairly constant, although the degree of inflation is suliject to slight variability. Ihe scales show a tendency to alternate on adjaoei-.t rows anri except near the ventral margin of arliilt shells the rows are not seoaratecl by definite grooves, '-^he majority of the specimens have nineteen ribs* !I!he Internal lirations usually eirtend over more than half of the dis- tance to the tunbo, althoxip-h on thick shells the distance is less. Yoiing shells are less orbicular than adults, being higher than •"ide, the sculpture on the interspaces is reduced to radial, rais- ed scaly lines, the ribs are merely roughened and their distal ends squarer, ■^'his species is recop'nized by the scabrous character of the sculpture and the almost ^oristant number (nineteen) of d is tally subrounded ribs. It is closely related to the Pliocene and Recent P. exasperates Sowerby (1), v.-ith which Gu.ppy first confused it. (1). Thesaur. CJonch., vol. 1, p. 54, pi. 18, figs. 18.^, 184, 186, (=?. f us c o pn.r pur e us Oonrad, 184:9), bu.t the recent form is larger and in^iivi duals of the same size are usually less orbic:lar, more inflated, with steeper dorsal margins, the scales arranged in more definite radial series and more prominent in the interspaces. Brovm and Pilsbry have des- cribed two varieties of this species; as oxyn-onus canalis (2) from ( r: ;> Proc. Acad. I'at. 3ci., Philadelphia, vol. 64, p. 511, ol. 24, fie-. 5, 1012. - ri7 - Gatun, which is larger, "-ith subeoual raiial striae on the ribs and interspaces and the srxrface less ohviously scabrous; and 03cyg-omiFi optimum (1) , from the Oosta ^.ioan Miocene and Antigua (2), (1). idem, pp. 511-512, pi. 24, fig. 2 (- P. paranensis Cabb, Jour. Aoad. ITat. S^i., ""hiladelphia, r'nd ser., vol. 8, n. 347, pi. 45, fi??. 24, 1881, non d'Orbigny). The Antic-uan form V7hieh Dall (loc. cit., pp. 717-718, pi. 29, fig. 5, 1"^98) described as P. gabbi, as a new name for Gab'^i's P. 'oaranensis. is distinct; Gabb ' s spe c inens came from Sapote, Oosta ?.ica, not Santo Domingo. (2). Brovm, A. P., Proc. Acad. Hat. Sci., Philadelphia, vol. 65, pp. 501-602, 191.-^. which also is larger, more inequilateral, with the dorsnl half of the ribs subrounded, the ventral half -reeled, radial striae on the ribs and interspaces crossed bj' irregular inerementals, the surface roughened, but not scabrous, the submargins foiraing a high, steep ledge. Sowerbjy's failure to orovide figures for his three briefly described Santo Domine-ian Pectens (25) has caused some confusion. i^)t Sovverby, G. B., Quart. Jour. Geol. 3oc. London, vol. 5, p. 52, 1850. It is- surprising that Gabb shoixld have identified the present form as oxygonus Sowerby since it obvioiisly conflicts with Sowprby's - 218 - diagnosis an'?, it is luif ortimate that later \7orkers have accepted Gabb's determination. There is no warrant for assigning the thet- idis Sowerby tc this common Pecten, as Dall has done, since Santo Domingiai^ spe^i";ens are knovrn that agree v;ith Sov^^erby's descrip- tion and probably with one of the valves under that n^i^ie in the neniker collection at the British I'useum (1), Gi^pp^^'s earl" con- (1). Information from I'r. Held, discucsea by Dall, loc. cit., pp.. 714-715, 1898. In addition to this valve there are others which certainly are distinct. fusion of a "Jamaican" Pecten with the recent e^rasneratus . an error which he later corrected and followed Oabb s example in calling it oxyg-onus. indicated that he had the present form in mind. In this connection it is surprising that Dall iised thetidis in a manner "which would agree v/ith usage as seen in the Guppy and other collect- ions ". (n) Apparently GuTipy had this common scabrous form labell- (2), Dall, 'Jy. E., loc. cit., p. 715, 1898. ^Srt'^ "^' v.^S^"^ ed "theti^.is" when his collection was accuirel by the national llus- eum. The Santo Domingian specimens of sumpleus reach a slip'htly larger size than the Bowden ones, 7:ith the scales arranged more - 219 - definitely in linear series tovmrd the ventral maro-in, the series separatee! by shallow grooves, an arrangement VThich is conoomitant with the increase in size, as is shown hy the Sowden speciriiens. The largest Anti??uaji V5lve, larger than any from Bowden, has a na.rrow, scabrous medial rib in the intersoooes near the margin. Fo Pecten resembling theti ciis is known from the Bowdcn beds; it differs from siimpleus by its more Inequilateral outline, higher, sharper ribs, their eummits with a shallow sulcus, bounded by a narroy/ radial on either side, vn.tla another rari.ial near the base, the surface of the radials roughener? by irregular, lo?; elevations, but not definite scales, along unequally spaced co;. centric lines. Occurrence.- U-TOer Oll.eocene: S nto Domingo (oO'.vl^.l'' -, ^TO; Gabb, 1873; Guopy, 1874, 1876; L'all , 1898); Anti.c-ua (Brown, 1917); Curacao (l>all, 1898); lower Miocene: Bowden beds, Bov/den, Jamaica (C-uppy, 3866, 1874; D^'ll, 1398). - 220 - PEG TEN (ASQ'JIPEOTSlO OZYGONUS Sowerby. Peotc-n oxygom^m Sowerbs?, 1850, QiLart. Jonr. Geol. Soc. Londor:, vol. 6, p. 52. Pecten aup-ttstioostatus Gabb, 1873, Trans, Am, Philos. Soc. (new ser. ) vol. 15, p. 256. Pecten ( Aegiiipecten) oxygonu-m Sowerby, Dall, 1898, Trans, "/agner Free Inst. 3ci., Philadelphia, vol. "^ , pt. 4, pp. 713-714. I^ot P. OT^j-onxm aabb, 1873, Guppy, 1874, 1876, BroT.-n, 1915, (= P. snmpletis n. sp,). Desori'otion.- "Testa suborb ■ oialaris, subobliqua, tumida, costellis radiantibus 19, superne acutangiilis, interstitiisaue aeqiialibus lineis incrementi concinne decussatis; ai^.ribus inaequ^li- bus, laevibus, radiatlm oostellatis, costellis tenuissirais." (Sow- erby, 1850). Type locality,- Santo Domingo, "Shell ST^iall, suborbicular, ■ ith nineteen to tv/enty-one sharp- ly Keeled ribs separated by V-shaped interspaces, with little-ele- vate-^, sharp, thin, concentric linear inbrication; form, tumid, cardinal crura well marked; left valve less convex than the other. Alt, ^nd lat, abont 15 mm," (Dall, 1 18, from type of P. august i- Gostatus Gabb), ■1 - Shell small, well inflated, subequivalve, snbor'bieular, slightly more prodxiced and tuieveiily roimded posteriorly; posterior dorsal maro-in longer than the anterior; rig-ht valve sculptured with twenty- tv70 or twenty-three angulr.r radial r ibs, the summit heing slightly roimded and on adult shells the ribs roiinde-"'' at the ven- tral margin, separated by angular interspaces, vath the apices of the angles rounded; on the slopes of ^>' <^ ribs and in the bottoms of the interspaces fine, closely spaced, sharply raised concentric lines present, usually not rising above the summits of the ribs; left valve sculptured with eighteen or nineteen similar, but broad- er and more sharply angular, ribs and similar concentric lines; submargins of both valves smooth e^ccept for very fine, inconspicu- ous concentric striae; anricles subequal, "i th four or five narrov;, unetiually sr)aced radial ribs, crossed by concentric imbrications; cardinal crura conspicuoxis,. finely striated. Dimensions.- A left valve: lat., 14 ran.; alt., 14.1 nim. ; diam., 3.2 ram.; length of hinge, 8.2 mm. A right valve: lat., 12..'! mm.; alt., 12.2 leu; diam., S mm.; length of hinge,, 6 mm. Remarks . - ^e two valves are of almost eraial co.ve"ity, but the left displays a tendency to be slightly less convex and more inequilateral. The radial sculpture on the tv/o valves is quite different; on the left valve the ribs are fev7er, broarier and more sharply angular, but still very slightly rounded, especially at - S22 - the ventral marg'in and in the umbonal region. The concentric lines override the rihs hut rarel;y and then are very faint. Two large right valves, i nrc-er than "'■Iip f^ne measured, that apparently' be- long to this species, have rihs v.hich are notably rounde '^ and even flattened at the ventral margin. As usual, young shells are more rounded than adults. The angular ribs are the distinguishing fea- tiure of this species, v;hich numerically is not a conspicuous ele- ment of the Pecten fauna. As Dall pointed out, 0 abb's Santo Domingian auft-usticostatus aprrees with .Sowerby's description of ozy~oniis« '^he fact that this form 1 s not similar to eny of those under the name oxygronus in the Henilier collection, as Dr. Dall learned from Kr. Reid, should not have much weight since it is evident that labels and shells in that collection are improperly asv^oeiated, a confusion which in all probability occurred after the completion of So";erby's work. -i^he type of aup-ust i co s t at us is larger than the Bowden spec- imens, with the median and posterior ribs sharply angular, the summits of the anterior si::- or seven slightly rounded, the poster- ior submarrin bearing weak radial s. Occurrence.- UT^^^er Oligooene: Santo Domingo (Sowerby, 1850; Gabb, 1873; Dall, 1898); Lower Miocene: Bowden beds, Bowden, Jamaica (Dall, 1898). — ;Oii e_< — PSCTEiy (A3QUIPEGTEIT) ELA3HISTU3 n. sp. Sescrj-Qtion.- '^hell small, moderately inflate!, Buborbieiilar, subequllateral; rip-ht vnlve nore inflateri +>,?,n '-lie left; exterior siirfaee of right valve sculpt urer^ with tv/enty-one roimded or sub- roiiided. radial ribs, separated by slightly narrower, roimded inter- spaces; concentric sculptiire of fine, but conspicuou.s, concentric raised lines, occasinnally overriding the ribs in the distal third of the shell and in the same reg'ion rarely extended sufficiently to form continuous concentric lines of slightly projecting, incon- spicuous, thin, scales; left valve sciilpture " with seventeen or eighteen strong, square radials separated by deeply impressed in- terspaces of the same width, with the concentric lines usually prom- inent in the interspaces and occasionally appearing on the ribs; submargins , auricles and crura as in P. oxyonus. Dimensions.- A right valve: lat. , 10 mm.; alt., 10 mm.; cliam. , 1.8 mm.; length of hinp-e, 5.5 mm.; A left valve: lat., 8.7 mm.; alt., T.S ram.; '^iara., 1.4 mm.; length of hinge, 5.9 vm, Rem.ark s . - P. elachistus. represente-'' by several valves, all of which probably are not m.ature, closely resembles P. ox y genus in general features, but the sculpture is decidedly different. Right valves of elachistu:. have fewer, fone or two less) broader, more rounded ribs, with correspondingly narrower interspaces, than -224 - the yoimg of os:;-p:ontis of the same size; on left valves the 'diff- erences are even sharper, since on elaehistus the rariials are square and the interspaces almost sruarely impressed, v/hile on ox y;? onus both ra^iials and interspaces are angiO-ar. left vslves of the new s-oecies are less tumid than those of ox^^o-onus. OGCijirrence.- Lor/er i.lioeene: 3ov/den beds, 3ov.-den, Jamaica. opr PEGTEIT (ASQUIPSOTEIO OOrOILTIIATUS n. sp. Description.- Shell of mec'-itim size, slir'-htlj" ineqiailateraJ ; left valve moderately' conve?:; dorsal margins converging at an angle of slightly more than 90°, the posterior dorsal marfrin heing longer. than the anterior, caneing a slig-ht prodiiction -oosteriorly ; exterior surface sculptured v/ith seventeen strong, almost flat-top- ped, hut rounded, radial ribs, separate:^ hj? interspaces of virtually the same width; concentric sculpture of relatively cor spicuoias, fine, sharply raised concentric lines, overriding the rios e: cept in the distal half of the shell, ^he lines "being arched in the in- terspaces with the oorvfiT pi'^e tnvr-'^rd the ventral margin; siihmar- gins sculptured \"ith co::. centric lir-es, finer than those on the ^isk; auricles suhequal, with radial and concentric sculpture; car- dinal crura prominent; right valve not "i-nov^Ti. i^i tensions .- left valve: lat., 14,5 mm.; alt., 14,7 mm.; diam., 2.S ram.; length of hing-e,. 7.5 mmC?). Her-'gr>s.- This sharply defiDP^ p^ecies is reioresented in the material at hand hy a single left valve, She strong, subroimd- ed radial ribs and, above all, the conspicuous, raised concentric lines over the entire surface of t>e ^Ji bV, except on thi distal portions of the rib.T, serve to distingixish this form from the assoc- iated .'.e^uipectcns. *. c j .centric lines are actually closely spaced, but the interval "betv-een them is wider than in the case of most species. Occnrrenor-.- XQ^^er Miocene : - :n,'be''S, Bovrden, Jamaica. Subgenus Pseixdamusiiun H. aiii A. Adams. Section PseuclamusiTTm s. s. PSGTEE {PS,TJDAI>:U3IUIvI) GIT^PYI Dall , T^e:;ten -f^: . .1 ..,■ 2Z22li.-'^all, ^. ., . . ..^^..er Free Inst. Sci., Phila-^elphia, vol. 3, pt. 4, pp. 718, 755, pi. 54, figs. 12, 13. Descriotlon.- "shell G::iall , suborTDicular, moderately? convex, smooth, vath the surface oovered with microscopic 'Jamptonectes striation; ears small, the anterior slightly larger, all with very minute radiation anrl concentric lines; notch narrow, small, with no ctenolium; interior smooth, without lirae or developed crura; tr-jces of the auricular crura alone 'oerceptible; cardinal margin hearing a sharply cross-striated, very distinct provincu- lum; "basal margins flattened, posterior margin slip-htly compressed. Alt. 6, lat. G mm. "The abimdance and ujiiformity of Ihis little shell testify to its a'lult character. Occasional indivi'-"'uals shav a thickened line internally on each side, on the lower e'ges of the suhmargins, like some recent species, an-'i also traces of coloration in hlotches." (Dall, 1898). Type locality .- Bow den, Jamaica. £28 - Henarlcs .- Ivumeroiis individnals of this snail species are present in both colleotions. On all except the most opaque shells, faint, microscorjic concentric markings, due to differences in the texture of the shell rather than to sculpture, are visible, and on a few more or less translucent, polished valves thece markings are quite distinct. Rg^diating lines on the auricles are seldom observe*^ and when present thev are subordinate to the inoons-nicuous concentric lines. ■: trie anterior auricle of the right valve the concentric lines are most lorominent and are slightly roughened. ^^ypicaX individuals are of the following dimensions: A right valve: lat. 5.9 mm.; alt., 5.7 mm.; length of hinge, 2.5 mm. A left valve: lat. 5.5 ram.; alt., 5.7; mm.; length of hin^'-e, 2.3 mm. The small, thin, smooth valves of this species, v:ith the mark- ed proviuculum cannot be confused with any of the coexistent Pec- tens. Pec ten (O::olo-oe etenl oligolepis Brown and Pilsbry (1) from Gatun is smaller, with a more roxmded outline and faint soul-oture. fl). Proc. Acad. Nat. 3c i., Philadel-nhia, vol. 64, ov. 512, 513, text fig. 5, 1912. Ocourrenoe.- Upoer Oligocene: Oak Grove sand, I?lorida (Dall, 1398); Lower I.Iiocene: Bowden beds, Bowlen, ^am.aica (Dall, 1898). Pliocene: Limon, Costa Pdca (^all, 1898). — .'j (^ ;? — SulDP-enLis Anrasiun (Bolter.) Schiomacher. Section Amnsium s. s, PSGTEK (AI.IUSIUlvI) .^APYRACEUS (Gabb) ? Pleiironectia npioyvaoea Gcbb, lO?."^, i'rans. Airi. Philos. 3oe., new ser., vol. 15, p. 257. Amusium X)a^:;raoevxa (Gabb) Dall, 1898, Trans. Wap-ner Free Inst. Sci., Philadelphia, vol. '^, ^^t. ^, ~r,, vis. Peoten ( Arnus ii-^jn ) pa-n^" r ac eus .Dall, 1838, idem, p. 757. Desoription.- "Shell discoirlal, sub-cirf?!!! ar, very slip'htly longer than v/ide; sli~htly inequivalve; ears nearly equal; sur- face per'eotl.y smooth, or raarkecl only by faint lines of gror/th; in- ternal surface marked vvith small double radiating ribc. Length from beak to base 2.2 inch, ?/idth 2 inches." (Gabb, 1875). Type locality.- Santo Dominpro. Remark's . - l^he collections at hanri contain a small fra,gment of a le.rs-e Amusium and tv.o frasn^-iGntary immature valves. I'he fragment 3ho77S that the ventral portion of the e^-rternal siirface is smooth except for faixit, closely spaced concentric lines; "hile the interior is cculptiired with ^oairei radlals. Both the distatice between the radials that form a pair and that between ad,ioining - 2r:0 - pairs is greater than on the type of pap^'raoei^s, describe'' from Santo ^omingo. 'i?he immature valves are higher than v/ide; auri- cles large, suheniml; exterior smooth except for faint, micro- scopic Gsmptonectes strij-tion. Gince the ventral third of both valves has been brolren off it is difficult to determine the char- acter of the internal sculpture; iff pa.ired radials were present near the ventral mar-'^-in, they are obsolete before reac^hing the portion rrhich is preserved. The distinguishing features of pa pv race us are its somev/hat ovate form, smooth exterior and psire'i internal radials. A recent Antillean and Gulf form is referre"! to this species. I'he valii^'ity of Its sepf^ration from the I'iocene and Pliocene P. mortoni Piav- enel (l), is doubtful, but that species is, hov/ever, usually larg- fl). ProG. Acad. ITat. S^i., Philadelphia, vol. ?, p. 96, 1844; -uomey and Holmes, Pleioc. Pos. South Carolina, p. 27, pi. 10, figs. 1, 2, 1855. er and more orbiculrr; P. l-i!^ia BroMi and Pilsbry (2), from Gatun, /" h has the a"aricles depressed belo" the plane of the disk, '•^he re- (2). Proc. ACad. Hat. Sci., Philadelphia, vol. 64, p. 514, pi. 24, fig. 1, 1912 (=pGCten ( Amusium) cf. I'ortoni .-^avenel, Toula, Jahrb. K.-k. geol. Heichsanstalt, vol. 58, pp. 714- 716, pi. 26, figs. 8, 9, 1908. remaining -Tertiax-j.- Aniusiums of the Oariblaean region have some form of external sculpture cr marking. ^oourrence.- Upper Oli^p-ooene: Santo Dorainfro (Oahh, 1877-). Lov/er Miocene: ?Bo'.vden beds, Bowden, Jamaica (Dall, 1898). Recent: Gulf of Mexico to Haiti in 30 to CO fathoms, oceiirring in both shallov/ and deep water off 7/est Florida and in deep water onl?; in the 'Jest Indies. Section Propeamusiiim de G-re^^orio. PECTEL' (P?.0?::i\I-,IU3IUlvI) 3PEKDULUS n. sp. DesgriT)tion»- Shell small, thin, com-oressed, suhorbio-ular, higher than '.'.'ide ; dorsal r.iareins with a steep slope; external surface of left valve scxilptnred with very fine concentric striae, obsolete toward the ventral niarp-in, mth faint suggestions of a feV' coarser, more wideljr spaced co.icenti'ic lines near the ventral margin; dorsal Valf of the shell hearing exceedingly fine radial striae, barely visible imder the microscope; the entire surface covered with camptonectes strictions; internal lirae faintly visi- ble from the exterior; airricles small, with a median broad ridge, separate-^ from the disk by a scarcely impressed line; interior with ten prominent, relatively heavy lirae, extending about half the distance to the umbo, thickened toward the ventral mar~in, but terminating before the margin is reached; distal extremities of the lirae acute, except the two nearest the dorsal mars-in, which are roimded; right vslve not kniwn. Dimensions.- lat., 5.8 mm.; alt., 6.1 rnr:!. RemarVs . - It is somewhat surprising to fine this delicate shell in the Bov'den marl. It bears a r^-^markable close resemblance to P. pourtalesianus Dall 1), one of the most common of the deep- er water species in the G-ulf and iintill ean waters and also, re- (1). Bull. Hus. Compt. Sool., Harvard, vol. 12, pp. 211-212, pi. 4, fig. 3; pi. 5, fig. 12, 1886. ported from the Pliocene of the Tsthmns of Tehuantepec (2). i^he recent form is larger, more orbicular, '.vith larger auricles, less conspicuous external sculptnre, the internal lirae not quite (2). B8se, E., Bol. Inst. geol. Ile-ico, no. ^2 , pp. 52-55, 1906. as heavy, le.^s swollen and pointed at their distal end, and extend- ing further toward the uraho. Oeciirrer:c e.- lov/er i-.Iioc ene : Bowden heds^ Bo-den, Jamaica. Fami ly Spoiifl ;vl idae . Genus SPOITL-'LUS linnaeus. '^POICDYLUS BOSTRYGHITiiS Guppy. Spond:v-lu£ "bifrons Sowerb;,-, IHoO, -.uart. Jour. Geol. Too. Lonclon, vol. 6, p. 53. Fot S. Taifrons Goldfass, 187'5. Spond: lus bostr;. ohites Gupp;^'. 1867, Proc. Sci. Assoc. Trinidad for 1867, p. 176. Spondylus bostryehites Guppv. Gabb , 187?, Trans. Am. Philos. 3oo. new ser., vol. 15, p. 257. Spondylus bostryolxites Gupoy. 1874, Geol. Mag., decade 2, vol. 1, p. 1-4-5 ( check list). opond.ylus bostrycliites Guppj.', Dall, 1898, Trans. .«ap-rier ""ree Inst. Sci., Philadelphia, vol. 3, pt. 4. ':)-p, 758-759. ? "ponci-rlus bostr:^Ghite3 Gupp^?, Dall, 191", ^,-11. U. S. ITat. !'us., no. 90, p. 124, pi. 19, ag. 4. Description.- "Testa subregularis, rotundata, ventricoss, raargine latiusulco, valide denticalato; extus radiatim costata, costis 5 ad 6 spinif eris ; area cardinali alterius valvae ann-usti- ssina, alterius latiori." (So'-verb,-, 1.^50). T^'Pe "' ocalit;y . - oanto Domingo. "The type form of this species has a relatively: small number of spinose ri^os, the \--:''p-:"^en±n^ ones being f'^pe from spines, longitudinally finelj' striate, and ahoTsai v/hen very perfect miniite scales. -^^he adult shell is rather short and rounded and less in- flated than usual in the genus, 'i^he specr-p is remarVahle for its small hin.p-e -area." (JJall, 1898). Tvro inmcture left valves apparently? should "be assigned to this species. They are thin, slig-htly auriculate, slightly inflated, moderately ineqiiilatoral, the posterior side heing more produced; ujnbones very low, weakly inflated; external surface sculptured with a varying niimher (ten ■^'^ :^ifteen) of I'^w, primary radial ribs, bearing at irregular intervals short, relatively stout spines; second.ary radial ribs and strir:e of irregular width intercalated between the primaries, transversely roxigheioed or slightly spinose; in the interval between two primary ribs one secondcry rib Tisually more prominent and more obviously spinose than the others; auricles poorly developer!, their surface omaniente'l with a few small spines or scales; cardinal area very narrow; innfer margin of the valve ir- regul-^rly and feebly erenulated. 'Ihe dimensions ~f the lar-^er are: 1st., 1?..- :a':i. ; alt., IJ^'.l ii^m. ; '"'iam., £.5 mm..; length of hinge, 6. 5 ram. ; A very small, proriortionately mr ravey^ left vel: soubtfully referre'^ to this soecies; it has the seconc' ary rr.disls suT)pressed and the few spines near the ventral marp^in are .dorso- ventrally coraioresser! . Remarlrs ♦ - jsnto Doming-ian speciniens of this species reach an enormous size, "being as much as 115 mm. hip-h 8az' 100 Mn. vzide, r;ith t'ne primary rt dials not prominent and hearing a few spines, the whole surfsce slightly scahrous. j?orms from other localities, incln.din.?? Borrden, are never of such an iaiposing size and oerhaos should be considered a distinct variety. The Bov;den form referred to this species is characterise'^ hy its moderately inflate"!, round- el form, relatively few, lo7/, narrow, spinose orimary ribs with intervening non-ST)inose secondaries and longitudinal striae on and between the secondaries. Speci'^nens from the type locality have the primaries narrower and less spinose, but a'onarently these char- acters are susceptible to variation, for specimens from other .Int- illean localities that are com"oarable in other features to those from Bowden have the sculT^tnre of the S—nto DominglaJi form, the ribs beijig as narrow or even narrov;er. The advisibility of includ- ing the Tampa sile^ form is doubtfiil since it is narrower, more inflated, witt- « v-id.er ©nd shorter cardinal area. A very closely related form, _3. chipolan^rs Dcll,(l) occiirs (1). loo. cit., 010. '^"':-7o9, 1338; loc. cit., n. 1^5, b1. 1^, fi5-. 1, 1915. in the Ohipola and Oak Grove faunas; it is more oval and inflated, with more numerous spinose ribs ai':d concentric striations on the seoonflarieB, Th^ smaller of the tvvo immatujre left valves at hanri. displays some of the charaoters of diip Planus ; it has more numer- ous spinose ribs than the larger, '.vithout radial : '"ions on the secondaries, but, on the other hand, the outline is that o." bostryohites and there is no trace of concentric striation. Occurrenoe.- Up^er Olig'ocene: TTampa silex beds, Florida (Dall, 1898, 1915); Tlimestone of V/hite Beach, -lorida (Ball, 1898, 1915); Sr.nto ^omin^o (Sowerby, 1850; Guppy, 1867, 1874; '"xabb, 1873; Dall, 1898, 1915); Antigua (Oooke, ); Anp-uilla (Gur)ny, 1874; Dall, 1898, 1915); Lower Liocene : ■;3ov.den beds, BoTden, Jamaica (Gu^-oy, 1874; Dall, 1898, 1915U - 250 - 3P01IDYI.US GOOKII n. sp. Description.- '^hell of raedixim size, pectiniform, sutorbicu- lar, subequilateral, conspicuouslj? aurioulate for the genus ; rifrht vilve decide dlj' inflated in the umbonal reg-ion; e::terior surface sculptured v/ith five to seven primary radial ribs, in the form of very broad, lov/, anrnlar, nriniary radials occupying the entire area of the shell and separated by longitiidinal depressions, or only their crests elevated as distinct ribs; the crests of the primaries bearir^g- stout, blmit spines at irreg -lar and widely s->iac- ed intervals; on the gently sloping sides of the primaries or on the flat areas that 'vvoTold for-^i the sides of the primaries if they ¥;ere elevate^!, appear secondaries, of irregular width, faintly striate T longitudirially aad faintly scabrous, with exceedingly fine scales arranged in very narrov;-, longitudinal series; auricles S'^arp- ly differentiated from the dislr, subeoual, slip-htly rou?rhened or scabrous; concentric sculpture represented only by fsint lines on the auricles; left valve only moderately uniformly convex; primary ribs never as bro'd as on the right valve, spinose, as on the Tl^-h't; secondaries more prominent and more sharply sculptured, occasion- ally bearing very short spines; inner margin of the valves irregii- larly crenulated; interior of ri^bt valve with inconspicuous broad, undulations corresp -ending to the external intercostal depressions. Dimensions.- Right valve: lat. 24.6 mri. ; alt., 24.7 mm,.; o r70 diam. , 9 mm. ; lenp'th of hir.p-e, 12 mrn. Remarks.- A fraginent of an apparently mature left valve, tv/o immature right valves a.j ^ ounger left constitute the reoresent- ation of this sharply-defined species, ■^'he fragment presents only the n.-i:bonal and posterior dorsal portion of the shell and therefore some uncertainty attenr^s its position; "but in so far as can he de- termined, the outline, sculpture and a^^ricles testify to its place in this species. The left valve is decidedly pecteniform sin:.'e it is only moderately and uniformly inflated, while the right valve is strongly inflated in the umhonal region. In sculpture the two valves are notably different. _S. cookii is recognized by its suborbicular outline, prominent auricles, strongly inflate'^ riprht valve, sciil-otured v;ith spinose, broad primary radials and finely scabrous, longitudinally striated secondaries, and moderately inflated left valve v.dth more equally developed -nrimaries and secondaries. 3_. bostrychites is less inflat- ed, less orbicular, more inequilateral, less auriculate, \"i'"h less pronounced sculpture, the ribs being much smaller and t;:e spines shorter. This species is named fo' Dr. 0. v7ythe Jooke, " '■".e 'J. 3. Geological '"urvey, "ho is making valuable contributions to the Tertiary molluscan "oaleontolor-y of the './est In'-lios. Occurrence.- laver J.-iocene : "Bo-.vden, beds, Eov/den, Jamaica. - P40 - SPONDYIUS (SOHTrv^^'^S var?) II-OIKIiirJS n. sp.? Description.- Shell small, equilateral, well inflate"!, high- er than wide; lunho inconspicuous; right valve sculptured vi'ith ele- ven or twelve radials, bearing closely-spaced spines, the spines very long for the size of the shell and slightly ciirved, occasion- ally giving place to broad, irregularly curled, transverse scales, extending across one or more of the primary radials; between the prinsry radials poorly defined radial rov/s of small irregularly spaced scales present, the rows interrupted by the transgression of the broad scales; auricles not nrominent, their surface rough- ened or bearing a few snines; crura prominent for the size of the shell; inner surface of the valve with irregular crenulations of two orders, the lorimary ones, corresponding to the external inter- costal spaces^ extendinf? up toward the iirabo as inconspicuous im- clulations; left valve not known. Dir>iens1ons.- Lat., 10 mm.; alt., 11.8 mm.; diara., S mm.; length of hinp-e, 5.5 ram. ?emarkvq.- One of the surprising features of the fauna is the presence of this small, beatifully sculptiired valve among the many ponderous shells. Although very small, it is remarkably close to the recent Antillean 3_» eol^inatus (Liartyn) /I), which .1 - has not "been recordel from anj^ liorizoii Ibv/er than the Pleistocenef 2) . (1). Univ. 3onch., vol. 2, fig. 154, 1784 i'^,. anierioaxi-.is Lamarok, Anim. sariS Vert., vol. 5, p. 188, 1819; "?eeve, Oonch. Icon., S-oonarln.s. tdI. 14, fig. 17, 185G; 3. s-'athnlif ems lamarck. etc. (2). Ga'oh's Santo Doraingian _S. americanus (Trans, im. ^hilos. 3oG. ( new ser.4 vol. 15, p. 257, 1875) is S.* '~"iout eight teeth; interior redial]^^ feeblj" grooved, the basal raargin crenulate-^. bj- the ribs; shell moderately inflate"?. Alt. 5.5, lat. 3.^, -liam. 2.5 mm." "This little shell is related to the I. Bronniana Dall fl) of recent faii.na, but is distixiguishe'l from it by its narrower and (1). Bull. .:.^s. Gorapt. Zool., Harvard, vol. 12, -np. 226-227; 18';^5; Proo. U. S. IJat. Mus . , vol. 12, o. 251, nl. 14, fig. 9, 1889. more solid hinge, v:ith o distinctly smaller resiliary -^it and " eavi-r and more solid shell." (Dall, 1808). Type locality.- 3ov/den, Jcraaica. - F51 - Shell very small, siibovr.- e-trigonal, decidedly inflated in the Tim"bonal region, sulDequilateral; the av.we of the lov/er T!or- tion of the posterior •'-r~in slin-htlj' more conve:: than the corres- ponding part of the anteri-^r margin; base gently arcuate; iimbones relatively prominent; exterior sia-face of the disk scTilr)tnred '.vith foirteen to sixteen strong radial ribs, on immature sVjells rounded throughout, but on adults beoom.ing angular in the dis'al third of their length and at the same ti~;e bearing minute nodulations on their sides; ribs seoarated by interspases of virtually the same v/idth; thro^ighoiit almost the entire length of each inter- S"oace a smsll, median, rouridec!, minutely nodulated ridge nresent; submar~ins sculpture" with ten to fifteen concentric rn.gae, the posterior subm.argin longer and usually having the concentric rug- ae more prominent and more nLTjnerous; ligament pit small, shallow, subumbonal v.lth six to eight teeth on either side; inner margin of the portion of the shell v/ith radial sculpture deeply crenu- late "" ; in"^erior if the shell ^dth inconspicuous rrdial nodula- tions corresponding to the external radial sculpture. -^inensi "'ns.- Lt., 7j nm. ; alt., 3.2 mm.; semJ.diam., .9 mm, •'•^em.ar'rs .- ''"his interesting srnecies is wel'' re'oresente^ in the collectiOTxS at hand. Despite the sn:a.ll size of the shell the sculpture is ver: sharply chiseled. One nf the valves shows traces of ri.'^r'k: coloration. Occurrence.- lower I.Iioeene : Borden be 'Is, Sowden, Jamaica. Snperfamily A IT 0 I.! I ;. . .J A Family ilnomiclae. Genus PLACLTiJIOLTIA Broderip. PIAOUNiUTOMIA LITEOBLETA Dall . Pla.ounanomia lithobleta Dall, 18''8, Trpns. V/gn-ner Free Inst. Sci., Philadflphia, vol. ?, pt. 4, vo, 778-779. -QesGrlptior:.- "'Shell resembling ^. oil oat a [-nomey and Holmes (l)J, "but flatter; not plicate, "but gently v/aved distally; (1). Pleioc. Pes. South Carolina, p. 19, pi. 6, figs. 4-6, 1855. surface ri::dially oeulptured with minute, almost microscopic, threads, v/hich are frequently interrupted, when the termination of the nvorA'^al loart of the thread is swollen, resembling a min- ute head or pustule; interior resenbling P. plicata. but the hinge wesiker, the amorphous irregularities confined to a. very small ST^aoe near the umbo, ^nd inconspicuous; crura of the lower vnlve small, forming an acute angle, well elevated, the socket for their reception on the or^posite valve shallow, Alt. about 50, lat. 50, diam about 8 mm." "Thic form is distingi:;ishable at once by its peculiar sur- - 255 - face sci.apture." (Dall, 1-308), I'ype looslity.- Bowden, Jamaica. Shel"! I'arp'e, thin, compressed, irregulcrlj' s Tib orbicular; irregultrl- ivarped and folded, the brofid undi:' '' being most pronoimced at the ventral margin, hut not definitely plicater!; inn- honal region occacionally sv/ollen; erterior surface pr^i:! iV-ured r.-ith fine, ^' ontinuous, swollen radial striae, broken up into longer or shorter portions or interrui^ted so frequentl"; that thev produce a finely; ^up.tulose appearance; bysssl plug on right valve elongated, triangular, almost extending to the cardinal margin; internal cardinal "rugosities" verj? feeblj? developed or obsolete; ri^-^ht v^^-'e v>'ith strong cardinal or^iv.'^, diverging at an acute angle; left valve v.ath a sharply defined, large, tri- angular umbonsl depression into which the crura of the right valve are received, the anterior and posterior distal portions of the depression separated by a triangular elevated area corres- ponding to the depressed area betrvveen the crura on the right va^ve. 5emar 'cs . - Several more or less incomplete valves of this S]5ecies, of v/hich the largest is about 40 m.ra. in latitu-ie and altitude, are at h^nd. It is the only member ^-^ •'■he genus ^lacu nanomia so far recorded in the \7est Indian Tertiaries. '"he gemis at the present time occurs on t'- e Pacific coast of Central Ameri- - 254 - oa, opt evidently? did not -^-orEist on the Atlantio side,, although luoiney and '"olTnes (1) notes its -nreseno . "^he hsrh^r of Ch!=)rles- ton. South Osrolina, an oocurrence 7,t:ich is discredited (2). (1). idem. (£). DaJJ. ..•• H., loc. Git., p. 778, 1898. 'The radial sc "!._ jf the Bov.'den species is irregularly deve- loped, oome portions of the shell, especially the umbonal region, rncy he smooth or the fine, swollen radial lines may cover the entire surface. V/hen ^resent the;; are alw3,ys mor(= ^r less inter- ri5.-ited. On one left valve these radials are especially r/ell de- veloped, being more prominent than on any of the ty^oes. xinother left valve, of whiSh only the ri-rr-:-T v-i-" -ip. -.-^reserved, has only very faint concentric markings aaul the hinge "socket" is, strange- ly enough, '"ithout the median distal raised triangular area. As stp-^'^d in -^iie ^-uoted dr p. n r -;_-,-. t ion, ] ithohletg -^ry iDe re- cognized hy its radial sculpture. P« pi i cat a Tuoniey and Holmes is a. smooth, marp-inally plicated form occurring in the -^uplin formation of f'-e Oarolinas, Occurrence.- Lower I'liocene: Bov/den.heds, BoA'/den, Jamaica (Ball, 1898). Genus AlIOMIA (Llimaeus) I.;il]ler. AFOLIIA ITIO HOSiLUaLlTA Dall var. IIIDHIOISA Dall. Anomia mi c ro g r anana t a var. InfTeoisa f Gup-nj? Mss.) Dall, 18T8, Trans. 'lagner 7ree Inst. Sci., '^hiladelpl-ia, vol. .'^, pt. 4, p. 785. -Inomi.a mie rofrranimata var. incJ-eoisa Dall, Bull. U. S, ITat. Mus. , no. 90, p. 1?6. Desorl'otion.- A. Tr.icro?raniniata "Shell small, irres-ulpr, oharaoterized "bj" a fine, almost microscopic, close-set ra.'lial striation covering the v/hole surface and flaring awaj" from the medial line of the valve in a somewhat wavy manner; the two loi;?er scars on the left vslve a:i:e suhecual and side by side, the major byssal soar larger, OD-cosite the nie^lipl line between them; the beak of the left valve is some distance within the margin, and the sur- face where worn appears smooth; the striation is only visible under a lens in most cases. Alt. 17, l?.t. 25 r:\m." "This species is recognizable, by its fine, almost divari- cate striation, which does not breal^ into piistu? es near the beak, as in the larger and more coarsely sculptured A, enhippioides. "The s-recimens from Bowden have a still finer end ofton partially obsolete striation. ■'"hey form the variety inde?isa (Guwiy, Mss)" (Dall, 1398). - r.5 6 Type local it:;.- 3owden, JamaiGa. Heraarh_s.- Only a few of the Bo-.vden Anemias can "oe referred to this variety -^nd they are soniev/hat dou.htiul. Ail of them are small, none exceeclino' 16 mm. in latitude or altitude. A. micro-. ■?rammata is a v/ell-defined species which occurs in the ?amoa silex beds and Ohipola marl. ^t variety indeeisa. is. hov/ever, of douht- fiTl validity. The radial striations, which constitute the charac- teristic feature, are very fine indeed on the specimens at hand and occiir only on very lir-ited portions of the shell. They are visible only under the microscope. Most of t?ie Anomias in the Bowden fauna are here referred to A. simplex d'Orbip-ny since they are smooth except for occasional exagp-erate-'' incrementals. A-rngr- ently simples itself m.ay have suggestions of radial striae and for that reason the advisability of establishing a va.riety for the 3ov;den forms ^vith mere siiggestions of radial striation is questioned. At the present time, however, it seems advisable to retain the varietal name. A. flori dana JJall (l), of the Oak Grove fauna, is larger and (1). loc. cit., ^T. 783, pi. 55, fi'^. 7, 1898. has, in a-dltion to obsolete faint radial striations, v;ea^ pustules and obsolete, feeble radial striations. A, ixmbonata GirTo:;,'an - 257 Oligooene srecies from Trinidad (1), is mirmtely, bizt conspiciious- (1). 1396, ^roc. U. G. ITat. ITiis., vol. 19, p. 525, pi. 50, fi?r. 6, 1896. ly pustular and without radial striation. Oeoiirrenoe.- lower i.'ioeaie ; Bov;don 'be'"s, Bov/den, Jamaica (Dall, 1898, 1915). '^.nn AiroillA oII.IPLEK d'Orbig-nj/. •^nomia eleotriea Gould, 1841, Invert. Mass., p. 140 (non J--innaeus) An oral a squamella -Aould, 1841, id., p. 140 (non Linnaeus)- Anomia ephip-oium linnaeus var., ^onrad, 1845, ?os. Med. Ter. U. 3. , p. 75, pi. 45, fi-. 4. Anomia sim-plex d'Orbigny, 1845, in de la Sag-ra, Hist, fis., polit. y natur. de la Isla de Culoe , LIoluscos, p. .'^71, -ol. P8, fiffs. ''1-^7. (Spanish ed.). ilnomia aoo'^tes Gray, 1849, Proc , Zool. See. london, p. 116. Anomia 3 out a"! d'OrTDi-ny, 185.2, Prodr. ^: "i . Strat., vol. ?, p. 174. Anomia sinrolex d'Orbigny, 1853, in " '' {< Sagra, Hist, phj-s,, polit. et natur. de I'Isle de Ovgl:, ..ollu.sques, vol. 2, p. .-67, pi. 28, figs. 51-53. (French ed.). Anomia ephippium Tuomey and Holmes,^ Pleioc. Fos. South Carolina, p. 18, pi. 5, fiP-'. 4. (non linnaeus). iBsre Anomia e-nhippium riuo:^'--^ =-ii4. Holmes, ^Post-Ploioc. Fos . South Carolina, p. 11, pi. 2, lis-. ll.(-«''" L.Y^nat-os). ilnomi a Oonradi d'Orbipnj?, Gonraa, 18 65, Proc. Acad. Hat. 3^i., Philadelphia, for 1862, vol. 14, p. 582. Anomia Oonradi d'Orhigny, I'l ek, 1854, MioG. Gheclc list. Smiths. liise. Coll., no. 185, p. 4. Anomia gl^^hra Yerrill. 1872, Am. Jour. 3ci., 2rd ser., vol. "^ , p. 215. Anomia eTohJ-or^liun Crabb, 1875, I'rans. Amer. Phil. Soc . (n. s.) vol. 15, p. 257. (liOi. Linnaeiis), Anomia jrlabra Verrill. 1875, Am. Jour. 3ci., Zvn ser., toI. 10, p. ^'^2, Anomia ephi'O'pium Oabb, 1C81, '^'our. Acad. Hat. .:oi., Philadelphia, End ser., vol. S, p. 580 (non Jinnaeus). Anomia Pa^/'fini Heilprin, 1887, Trans. ?/agner Free Inst. 3ci., Philadelphia, vol. 1, p. 102 (non Jonraci). ilnomia sinrplex d'Orbienj-, Dall, 1889, Bull. U. S. ITat. llus., no. 57, p. 52, pi. 55, fi^s. 1, 2. -toomia sinnole:?: d'Orbi^-n;. , 'jUP'cj- and iJall, 1896, ?roc? . U, S, Fat. IIus., vol. 19, p. 52 6. .Inomia simple:: d'Orhigny, Dall, 1898, Trans. V/agner Free Inst. Jci., Philadelphia, vol* 5, nt. 4, p. 784. Anomia simplex d'Orhisny, Glenn, 1904, Maryland C-eol. Survey/, I.Tioo. vol., r,. 769, pi. 98, f i? . 1. Anomia simr)lex d'Orhigny, -^all and "^inpson, 1901, Bull. U. 3. ^'ish Oonm. , vol. 20, pt . 1, p. 468. Anomjg slir.plex d 'OrTDl^rnj/, B''5se, 1905, 3ol. Inst. geol. Me'-ico, no. 22, PT5. 25, 75, pi. 2, figs. 18-55; pi. ^, fig. 5. ? Anomia sp. indt., I'oula, 1908, Jahrh. ".-k. geol. Reichsr.nstalt , vol. 58, p. 711. Description.- "Shell of me-Hum size, suhorhicular, thin, of- ' 60- ten trajaslucent ; the left valve inflate'', the right- flattened; mn- "bones central, almost 'biit not quite terminal ; exterior surface usu- ally' smooth, with a fevf e" agger? -f^e " p-rov;th lines, sometimes deli- cjstely wrintlel; interior of valves possess the eharaoters of the gen-s." (Goiiia, 1841). _Hemar]£S.- Host of the Bovt'^^-'^ -^^ -"'^esentatives of this genus are, es state" ahove, referred to siraplex* Ihej' possess the accept- ed diagnostic fea^^ure oT this protean form - the smooth exterior surface. ITone of them exceed 17 nun. in latitude or altitude. As would he ex"Dected among small forms, the grov/th lines are not Gonspicuouslj? emphasized. Gupioy and Dall reporte"' this species from the "Oli-ooene of Jamaica" in 1896, but it does not apoear in the 190?) check list. At least some of C-ahh's Ganto Domingisn ephippium appear referrahle to this species. Toula has merely mentioned the presence of a "kleinen dilmisch;~ligen bltitterigen Anomia" in the Gatun fauna. Occurrence.- Oligocene: 3anto jJomingo (Gahb, 1872); lo^^er I'lioG ene : 3o',"den beds, 3owden, Jamaica ( Guppj- and Dall, 1805); Kiocene : Calvert formation, Virginia (Gardner, Hss.), St. Llary's formation, L'-aryland (Glenn, 1304), Vir^^-inia (Gardner, I.Tss.), Yorktov/n formation, Yirprinia (Gardner, lusrs.), Duplin formation, ITorth Carolina (auetores), Choctawhatchie marl, "Florida (Gardner, Hss. ) ?liocene: I-'ashua marl, i^orth Carolina, (Gardner, liic). :6i - Oroatan formation, I'orth 3r,rolina (Gardner, I,!ss.), '.Vacc^amarr form- ation, y—^'- •--"" Jouth Carolina (auctores^ Jaloosahatchie marl, Florida (-Uall, 1898, liraon, Costa Rioa (GaTDb, 1081), Santa Kosa end Santa Maria Ta'- " , Kexico (Bose, 1906). Pleistocene: Atlan- tic and Gulf coasts from South Oarolina so"-^' rd (Dall, 1898). decent: Jaue SalDle to I.-artinique in less than IS fathoms. Superfaniils/ K Y T I j- A G E A Family Llytiliclae. Gemis MODIOLUS Lamarck. Section Brachj'dontes Swains on. '■t/ MODIOLUS (BRAOHYDOIITSS) GUPPYI Dall . Modiolus (BrachTdontes) GwDpvi Dall, 189 8, Trans. V/asner ?'ree Inst. Sei., Philadelphia, vol. 5, pt. 4, p. 794, pi. 35, fiR-. 16. Desori ptior..- "Shell small, thin, delicste, radiately num- erously rllDbed, the ribs hut seldom dichotomous, general form as in n. grammatns. [Dall (l)J , hut shorter and more rounded, the surface frequently concentrically faintly undulated, inner dorsal margin shraply crenulate, the rest of the shell margin almost smooth, basal ena of the valve rounded, dorsal angle obsolete. Alt. 8.n, max. lat., 4.7, diam., 2.5 mm." "This differs from the last fn. S'rariimatus Dh1]J in its more delicate and less dichotomous ribbing, its more rounded, thirjier, and less angular shell, and in the absence of crenulations over most of the margin, due to feebleness of the sculpture." (Dall, 1898). (1). Idem, P. 794, pi. 30, fi.~. 2. Type loo ality.- Bovvden, Jamaica. Shell s;:'iall , thin, transversely elonga^-e, widest at about the middle of the shell; umbones i.^flated, almost terminal; um- bonal ridge strong, but rounded, becoming lower and broader post- eriorly; prosiimal third or more of the dorsal margin straight, forming a subrounded angle of cbout 140° with the distal portion, vrhich is gently curve'' or slightly emar^inated; ventral marp,-in usually slightl., concave; posterior margin narrow, abruptly round- ed; external surface sculptured v/ith numerous, inconspicuous, round- e'"i radial ribs, separated by interspaces of the same ?;iclth or nar- rower; r'-rdials usually obsolete on the most convex portion of the um- bonal ridge; co-centric sculpture of usually faint incremental lines, occasionally e^ ag.n-e rated; hinge often with sugp-est iont. of denti- tion, with two or three projections on the left valve and obscure sockets on the left; oroxir-al portion of the inner dorsal Diarsin con- spicuously.' crenulated, the distal portion weakly crenulate^. and the remainder of the marp-in usually axiooth or very feebly crenulat- ed. I>imensions.- Max. lat. ( do rso- ventral) 5.5 j;im. ; alt. (antero- posterior) 10.5 mm.; semidiam., 1.8 mm, 5emar-:s.- l^his solitary member of the gcmzs is well represent- ed in the material at hand. i^he width varies eo ns iderabl; , the valve measured being the widest. The angle between the two portions of the posterior margin is not sharp, but rou::ded or siibrouiided. A rather sur-orising feature is t?ie indication of hinge dentition on aiooarentl;!; adult shells. One of the left valves shows t'^ree small, but distirist, projections, viiile ciost of the others have suggestions of two or three similar processes. Sifrht valves h^-'ve Gorres"oo- i:1i ri?, but obscure, -le or ess ions. K, gu J ^y i maj." be recognize! by its nunerous v?eak radials and by the presence of de:^inite crenulations on only the dorsal por- tion of the inner mar?-in. The ciifferences betv/een this species and the Tampa silex grapiTnatus Dall are stated in the above quotat- ion. In the case of M. grariimatus var. curtulus Da3.1 (.1) , of the (1). idem. Ohipola marl, these differer.ces are even more r; renounce'^ . '^'■r.e recent Antillean M. citrinus 3olten (2) is larger, wider, more (E). i:us. Bolt., let ed., p. 137, 1798 {= lu. suleatus Lamarck). rounded anteriorly and the entire inner marc^in is orenulatei?. Occurrence.- io~er I'iocene: Bowden beds, Bowden, Jamaica. (Dall, 18 08). Family Dreisseniidae Gemis DR2I33EITA Yan Bene den. DaLTS^SI'A DOOEIEAM (Kickx) var. j;iI.:AI0J:"3 IS n. var. DeGcriotion.- Shell of nediumsize and thickness, out- line var'ing froin lonp-it-ariinally elorr-^te to subfalcate, great- est width slightly oeaiiid c.-.e ::iiddle _ u .ii ;iiell; dreicledl;;? and -unequally convex, the differential Gonve:city caused "bj? the ventral position of the iironinent, hirh, hi^t rounded, umhonal ridge, its axis beinr: ;iL"uuai:e-' elo;:e to ^he veiibral iiiarp;in throiighout; umbo acute, terminal, hent forward; dorsol margin convex, suhanprular to oroadl^v curved throixrrhout ; ventral mar- giii concave throughout r flexecl out\7ard before ;_'oiiiing the abruptly rounded posterior r.arrin; external surface sculntured •"ith irregularly dispose", oGcasi~nally eira?" ', increment- al lines, usually most conspicuous ne-^r the r.:ar;-lns, and a few, ohscure, irregular, concentric nrndulat ions ; lunbonal septum hi.p'h and v.l de for the "i-^e --^ tte chell; left vplve "1th a rel- atively large, shallow, veutrally situated 3oa.-:et, co-xei^ .'end- ing tooth in the ri^ht valve ' looed or obsolete; lig- srnent si p-roove promitient, occunyir^- more than a third of the proxinal portion of the dorsal margin. Dimensions,- lHar.. lat, ( dor so-ventral) 9.5 mm.; alt., ( antero-postero) 18 mm.; nemidia... , . ..... .:. OO !RemarkG_.- !rhe or.tline and width s-re quite variable; tlie dorsal mar ""in roay "be subangiilar , as in the c tse of the t^-pe ( with the angulation Gituated at ahout a third of the 'Hs- tance from the u ho to the pes terior inar^-in) or ahtuptly con- ve-c, in whioh oaae the shell is wider. In a similar manner the ventral margin varies from decide''' concave throughout to concavo- convex, the latter outline "being caused ■"■ '-he reflection of the posterior portion. The socket on the hirjge of the left valve ir? pronouncerl, hut none of the rirht valves. have a "-ell-develoo- ed corresr)ondiiTg toot: . Jor 3o-ventrall;>- the shell "- ost eon- vex near the ventral mar^:"in, while in an ant ero- posterior line the greatest convexitj^ i s at about the middle of the shell. The Pleistocene (1) and Recent D. cochleata Eickx (2), from the east coast of the Panama region, is so close that (1). Brown, A. P. and Pilshr^-, '-I, A., Proc. Acad. Lat. Sci. Philadelphia,, vol. 63, p. 497, 1913. (E). the tv;o forms can hardly he separated; the Bov/den form, is, hovr- ever, smaller, more slender and in general more abruptly convex. Occurrence.- lower Kiocene ; Bov/den beds, Bowden, Jamaica. - S67 - Pam i 1 5' Jul i i d ^ e . Genus JULIA Gould. ^ A JULIA GA.JKSRAE n. sp, Desortptio-'..- ..hell small, t r.^nsverselj- elongated, \7ell- inflated; dorsal margin arouate; roujided r- " iorlj?, base sloping toward the posterior end; rmho prominent, placed at the anterior end, strongly hent doTrn~-; rd over the xiciiro.;, 'deeply impressed limiile the margin oelow the Innule sloping do\'7nv/ard to the prominently procliif^ed antero-ventral angle; anteriorly with a suh-roimderl ridge curving from the umhc to the produced angle, the area het^veen the ridge, and the margin flattened; exterior s:irface smooth, escept for irregular incrementals ; hin^re e'^'entulou;: ; on the right valve the inner edse of the luxiule flattened and extended the martrin he- low the lunule orodixce'' outward by '''he thickene' ventral edge of the lunii-le; on the left valve the inner edj?e of the lunule thickened . Di-.ensions.- Lat., 8 ram.; alt., 6," i-x:» ; semicHam., 2.2 m;::. Remarks.- A number of valves, of v/hich t-o are ?dult, of this interestiiiir sToecieQ are at hand. The genus is at the present time confine"! to the ludo-x'acif ic region. One species haf. ' r. describ- ed from the American Tertiary deposits, the Ohipola J. floridar.a Dall (1); it is less elongate, smaller, v;ith more flattener! and less strongly curved umbones, smaller and shallower Irmule and inore 'oronoiuioe'l anterior carina. fl). Trans. Wagner Free Inst, Sci,, ?hiladelx)hia, vol. ,?, ot . 4, p. 811, -ol. 35, figs. 1-3, 1898. This species is narae'^ -^"■"^ '!> ss J. A. Gardr^er of the Johns Hopkins University, "/ho is malcing notev/orthy contributions to the Tertiary paleontology of the Atlantic Coastal orovince. Oociirrence .- lov^er Miocer^ : B-^v/den heds, Bov;den, Jamaica. Orrler A II 0 K A I 0 D 2 S M A 0 E A . Superfamily P 0 H 0 I.I Y A 0 E A . Family Verticordiidae . Genus VSI^TIOOHijIA 7ood. Subfrenus Trigonulina d'Orbipnj?. VEHTIOORDIA ( THIGOITUIIIJA) BOV/DEITSITSIS Dall. . Yertioordia (trigonulina) bowde... ..^is Dall, 1903, Trans. ;/a-~ner Free Inst. Sci.. Philadelphia, vol. 5, nt. G, p. 1512. Desoription.- "Shell snail, rotund, rather convey-, v,-ith eighi or nine anterior radial ribs v/ith deep, sube^ual interspaces, then a wide spaoe f ollcve 1 by tv7o ad.-aoent ribs, then a much wider space with another ad.lace-it pair beyond it seoarate^. by a sm::oth area, lar-er in the left than in the ri-ht valve, from the posterior margin; the surface when intect is covered -ith minute granules arranP-e'-i in rows harmoni,^ino- va th the ribs; lunul e very deeply im- pressed in the left valve, less so in the ripht; tooth of the ricrht valve large and strong, the posterior marp-in of the left valve mod- ified to form a lamina or lateral tooth received in a groove of the o-oT^osite valves. Lon. 2.?, alt. 2.6, diam. 2.0 mm." "Very similar to V. Gossiranni [ball fl), Jackson and Jhipola] (1). idem. - 270 - iDut more x)lump and orbicular." ( iJall, IQOo). '■J^ype looaJit^.- Bowden, Jamaica. Remarks.- iY^t small valves of this species are alDundant in the Aldrich collection but much lesy numerous in the Duerden col- lection, -^'he largest valve has the following- dimensions: la.t. 5.5 mm.; alt. S.5 mm.; diam. 1.5 ram. -^all has noted tr.at this form was labelled "V. ornata d'Orbign;-" (1) in '^upp^'s collection; (l). In rie la. Safrra, Hist. Ph;,s. jJolit. et natur. de I'lle de Ouba, Hollusques, vol. 2, p. 292, pi. 27, figs. 39-53, 1055 (French ed. ) . that recent species has fe;"er, broader ribs and broader interspaces. Aldrich (2) has described V. dalliana from the Oligocene of -^ed Bluff, Mississippi; it is small' r, more compressed and with sharp- er ribs. 2cG_urr_en£e_. - lower Miocene: Bow/den befis, Bowden, Jamaica. (Dall. 1905). (2). Nautilus, vol. 16, no. 9, p. 100, pi. 4, fi?;. 18, 1905. - 2 71 - Subgenus Hal iris Dall. 'o TSRTlQOliDll (HiI.I::lS) JAIvIAIOEIISIS Dall. Yertjg ordia (Haliris ) ja-iaicenc-is Dall, 190?, Trans. '.Vagner "^ree Inst. 3c i., Philadelphia, vol. 5, pt . 6, p. 1511. Desoription.- "Shell small, thin, subouacirate, inflated, with strong-ly prosocoelus bea>:s; sculpturtd. with about tv;ent^- seven radial close- set ribs with narrower interspaces; a smooth, deep lunar impression in fro.;t of, and a narrow, oscutcheon-like smooth area behind them, the whole surface mimztely grcnulose; basal mar- gin angularly produced near the middle, internally minutely fluted in harmony with ribs; hinge normal; Alt. 4.75, locir . 4.5, diara. 4.6 mjn." "This has a s-eneral resemblsnce to 7, mississir)"oiensis .all. (1) Eocene , but is smaller,, thinner, proportionately shor^'-er, (1). Idrm, -gv, 1510-1511, pi. 42. fig. 1. and more inflated." (Dall, 1905). ■'•'ype locality.- Bowden, Jamaica. Remarks.- Some of the valves at hand are larger than the :"ational Museum speci- ens, one being especially large, with the follov/ing dimensions: lat., 1?,.5 mm.; alt., 12 mm.; diara., 5.5 mm. ^ome soall riffht valves are decide^'^ly more convex and hip-her than the averf-^e form. Adult EhollE arc hesvier, r.lth the internal flutings iiieonspic ous and the baual angle niore or less straight- ened. In view of the la r~e size of some of the va?i.ves in the Gollections '"hioh hsve furnished the inaterial for this at:-'!;;:, it is evident that jamaieensis is larger than nii s s i s s i p;oi ens i s . The Bowden form is closer to V. c uad ranc-^-.l ar is Aldrieh (1), from the (1). Nautilus, vol. 16, no. 9, p. lOl, :ol. 4, figs. 22, 2?, 1903. siej 31ufi Oli'^ocene, but that species is heavier, ?vith a more decided ventral angle on adult shells, fewer and voider ribs and narrower intersoaces. Ocourrence.- Lower Miocene : Bowdon beds, Bowden, Jamaica (Dall, 1905). Parail^' Poromyacidae. Genus POHOMYA Forbes. POHOMYA JiI','IAI OiiKS IS Dall . Poromya jgnigiQensis Dall, 1903, Trans. vVagne r Free Inst. 3ei., Philadel^ohia, vol. F, pt. 6, p. 1309, pi. 55, fi?. 23. Desoription.- "Shell anall; hinge. Interior and surface sculpture Hire those of P. rranulata !"yst {and V/estendorp (l)J, but differing from it by the absence of rostration at the post- erior end, which is evenly rouiided thoiigh more attenuated than the anterior end. Length 5.5, height 4.7, diameter 3.0 nm. " "All of the s-oeciiTiens found agree in snail cize, absence of rostration, and closeness of the granular surface sculpture, which (1). JTouvelles 2es» dc s Oog. Foss. d'Aavers, p. C, pi. 2", fig. -, 1839. (as Corbula ?ranulata) ; H. and A. Adams, (Jen. Piec. Moll. vol. 2, p. 257, pi. 97, figs. 2a, b (as Thetis .g-rsnu- . , lata. ) , . , . , is dispose'? in radial linns." (Dall, 1903). ■i-^yoe locality.- 3o«'den, Jamaica. Shell small, subequilateral , being more produced posteriorly, decidp'^'ly inflate'"!, cnm'nressed toward the t>o _, jr end; antero- dorsal marsrin excavate", roux^ding into the broadly curve-^- anterior - 274 - end; postero-dorsal margin longer, straight or slightly convex, with a steeper slope; posterior end more attenuated than the ant- erior, rotuidp'^ ■'■0 p-'T^-^-'^imoated ; hp^'^' -\-^^r. ^ slight posterior eraar- gination on valves v/ith a de:?ided posterior production; umhones tumid, high, prosog;;rate , area in front of the umbo slightly ex- cavated; external surface v;ith conspicuous granules, ohscurely arranged in radial seri , -ranules finer toward the poster- ior end; ligament area opisthodetic, narrow, flattened, extending throu-^i.-j-.u the length of the posterior dorsal margin, poorly de- fined on the left valve; chondrophore conspicuoiTS, placed "behind the irmbo, directed towsrd the loosterior end, almost external on the left valve; hinge with an obtuse rip-ht cardinal before the chondrophore, a corresponding left deep, triangular soclret and a long left posterior lateral, form.ed by the compression of the mar- gin; interior of the valve subnacreous, v/ith obscure radii, the ventrsl margin finely crenulated and the margin at the nosterior end compressed. I)ir^:ensions.- Lat. V.5 mm.; alt., o.5 mm.; semidiam., S.5 mm. P^emarlrs.- -^'his species, which is v;eir i^esented, is recog- nized by its outline and granulation. Variation in outline is apparent, come of the valves being slightly produced and roimded posteriorly and others decidedly produced and subtruncated. ^he YPlves that are most decidedly roiT'-de'" "oos'^^eriorly are us'zally right valves and a concomitant feature is the lower and broader - 275 OTitline of '"he P-rnbones. The granules inay he ohviousl^' arranrred along- radial lix/ufe, o.-t; such arranffment is often ohscr.re or even ah sent. Oceij.rrenoe .- lower Miocene ; Bowden heds. Bow den, Jamaica* (Dall, 1907,). - -276 ]?amilj/ Gnsr)iclariidae. GrenvB OU^^riiJArilA IJardO'. Subgenus Gardiomya A. Adams. GUSPIDAEIA (OARilOMYA) ORASPEDOIIIA Dall. GiT spiel aria ( Gai-dioin:;a) oraspedonia Dall, 1905, Trans. V/agner Free Inst. Sci., Philadelphia, vol* .? , pt. 6, p. 1506, pi. 57, fie. 17. Desori potion.- "Shell small, plump, rostrate, the disk sculptured \vith numerous elevated, si'^vole, radial threads, with, in the interspaces, from one to three much finer sube- ual threads, the whole crossed by fine concentric lines of growth;- the major radials increase somewhat in prominence nea.r the posterior end; bea"ks low, submeiian, inconspicuous; rostrum small, short, slight- 15^ recurve'l, subtruncate terminallj', scul'otured concentrically with a single feeble thread extending from the besks to the lower posterior extremity; hinge normal, rosette ver^- small; interior b" sal margin fringed by small projections corresponding to the major radial sculpture, length 4.0, height 2.5, diam. 2.0 m.m. " "This sr;ecies is nrobably the one referred by Guppy to G. alt- _ cry _ ernsi'^a OrTDigny (1), a recent form Tvhieh it receniTDles, but vvhich (1). In de la Sagra, Hist, ph'-s., polit. et natur. de la lie de Cuba, Lioiliisques, vol. 2, p. 286, pi. 27, figs. 17-20, 1853 ( French ed. ) . is "i-^r ^r an:''- has the rostrujii radially sciilpiaired with niuiierous threads." (D&ll. 190?). •'•'ype locality-.- Bowden, Jamaica. Remar'TS.- 'fhis species is represented "by only a few valves. The Santo Domin?rian form '.vhich Gahb (2) designate;"! G. alternata (2). Titans. Am. Philos. Soc, nev/ ser., vol. 15, '. -^j, 1375, (ae ITeaera alternata). is larger, more eloi'igatei, with a higher rostr-um and no secondary radials on the anterior half of the shell; his (5) G_. ornatissima {7), Idem. is also larger, v/ith fe7/er radials, as in the recent omatissina d'Orhigny (?>). ("). loc. cit., p. 2go, j1. 27, figs. IS-IC, 1667.-, - 2 70 - The suggestion mar'.e 'oy Dall concerning Giipp;;. presumably re- fers -^0 Cupp2,^'s (l) 1874 check-list where "ITeaera costellata Lesh." is re"oorted from "Jamaica." (1). 3eol. ;.:a,q-. , decade 2, vol. 1, p. 441. Occ^gr rencs .- Lower Kioeene: Sodden "beds, Bowden, Jamaica (Dall. 190.^). _ ?^ 9 _ Subp- enx:is Bo~;denia ^all. OUSPIDARIA (BO..VDEi:iA) DI3TIRA Dall. Ji-apidaria f Bcvcleuia) distlra Da.ll, 190,?, Iran3 , V/agner ?ree Iiist. Sci., Philadelphia, vol. 5, pt. 6, p. 1506, pi. 57, fie. 16. Desoi-ip"^ion.- "Shell small, plump, v;ith elevated iDe'aks nearly centrally cit -ated, attenuated, rostrate, and conroressed 'behlnc!; sculptured 7;ith t-.70 strong threa.ds, one on the anterior dorsal slope ?,nd the other near the posterior "border of the disk, which "by its projection angulates the hasal ras-r-; ; 'itv-ieen these tv.-o the surface is finely, radially striate,, and a few nearly obsolete stria tions occur "behind the posterior thread; rostrnm compressed, straight or a little ^Tno'irve', nprrl;: snooth, ' ■"ar'ip.l striae on its hasal aspect, roundel terminally; hi. p-e as descrilDe- in the diagnosis of the subgenus; basal marp-in entire er^cept Khere the rar'ial ■^■'-rerr' forfss s n^'pll -n-^o -ection. T,prn=-th '^, hnirht S, diameter 2 nnn." "This li'-tle shells recalls Luzonia rnonosteira [Dall (l)j of the (1). Proc. U. 3. i;at. Mus., vol. 12, p. "1, pi. 8, fig. o, 1889. ^ O '"*, ree-ent f amm , "but b? s a different hiiige." T;/pe local i t_v . _ B ow d en , Jam ai ca . "\eTTiarlrs«- The . ./_- - .,j of this s-^en-'fis, the t^'^p ^f the siil)- geniTS are abiuidaait , Taut, as v;ith thie otl'^r Ju8-oidarif. , all of the specimens are from the Aldrich eolleetion. Drll (1) Pave the follow ing -"liapiiosis of the RuhTomis : "Sculpture like ^!prr!i om^'g ; hinpe (1). loG. cit., p. 1504, 1905. vath a posterior left and anterior right cardinal, the resilium "between them, but no laterals; the raarp-ins of -the right valire ^.-roovr. (=!^ 1-0 receive the e:T[. _.. ,._' the valve o-or,o?^ltr. 'a -^Vo right valves .at hand, however,- there is a very prominexit posterior card- inal and the edge of the mar.rin immediately behind the chondro- phore i8 ■.i-r,ini;ne''' en-'i- '^>1.^>ened for a short dis'-ance so ^^s "^^o produce aii incipient anterior oarcTinal ; on the left valve the hinge line is ahru-ntl: arched post eri oris? to receive the posterior right cardinal, vfeile "behind this emargination the •-■:•-'■ ^:V,i r-'Vpr.rrT - -d produce'"": to form a weak posterior cardinal. Jhe doy^l mar -ins of the right valve are grooved, the posterior raoi'e deeply than the anterior. Tae largest valve has the followin" "'I -^"sions ; ■'^-r-^Tn^ 4 mm.; alt., 3.S rara. ; diam. , g mm. 0_. fX'USonia) monosteir:., occurring' o-^f "^■--■^■■i, -i- r-i.-f-Vo^Tf- laterals or left cardinals, the right valve having an anterior _ O O -I _ oardinal arA is without the feehle external radials, viith the rost- rum ahruptly truncated. Ccourreiiae.- Lower Iliocene : Bov/den beds, Bowden, JaQiaica (Dall, 1905). order T I] I -. 0 D S S M .A 3 E A . Superfaraili^ A3 _ .-^ ?. T A G S A . Pamily Orassatellitidae. Genus aH-'VoSATELLI TLS Krttger. Subgenus Grassatellites s. s. Section Scara'bula (Gonrad) Dall. ■0HA3SATSLIIT3S (SGAI.IBUM) JAI^IGEIISIS Dall. Grassr.tellites ( Seainl)ula ] J ana io en sis Sail, 19b3, T ans. .'/a-^ner ITree Inst. 3ci., Philadelphia, vol. 5, pt. 5, op. 1471- 1472, pi. ^.n, fio-. 15. Description.- "Shell solid, nearly equilateral, suhtrigonal, rounder! "below and in front r;ith posterior end obliquely SLih truncate and a feeble carina bou..ding the posterior dorsal area; lunule end escutcheon subeoual, moderately impressed; nepionic shell flattened, with seven or eiP'ht concentric Io'n umdula tions, which extend, down about one-fourth of the way to the basal ruarrin mesial - ly, and on the anterior slope are continuous, though the greater part of the dislr and the v;hole of the -nosterior dorsal ar:a are smooth except for incremental lines; hinge norraal, the posterior right cardinal nearly obliterated; laminar grooves deep; internal rr.arrrins of the valves smooth. Ton. at ^ o--^. -v ^ ,--5,-,,. -r, r^im." (Dall, i9or:). Type locality.- Bowden, Jamaica. RerBr''S .- Several vnlves bel orio-ing to this species are in the oollections at hand, the largest having the follovTinn rliTnen- sions: length 47.5 nmi. ; "1~., ^8 nim. ; ;-'"rniaiam. , 11.8 ma. i'he shell is slightlv depressed in front of the posterior carina, hut not enoiieh to affect the margin. 3etv.-een the carina and the es- cutcheon is another fainter carina; midway oetween the tv70 carinae is a faint, shallow sul n the ventral half of the shell. The relative v/idth of the limnle and esoiitcheon is inconstant, hut in length they are snbequal and the Iminle is usually more deeply ipresse"!, On the. largest valve the concentric undulations are somewhat irrogiils r on the ventral half of the anterior slope. 2. :amaicen!jis is disting-iished "by its sub equilateral outline and the presence of concentric undulations in the umhonal region and on the anterior slope. D^]l has f'escrihed a very closely re- lated s-oecies from the Ohipola r.iarl- J_« chipolanus il]i The typi- (1). loc. cit., p. 147?;, pi. 49, fi?-. 1?,, 190."^. eal Ohipola form -differs in having fine coii-^entric undulations on the entire snvzi _, ----ce-ot on the posterior slope. This con- centric sculptiire niay be obsolete or may be "present on only the anterior third or less of the shell. 3uch forrns are "Ufr'erentiat- ed from j ama i c e ri o i p. b ' "i-nvT- c- fT^.m ^~"^ ^'^ -f'liri- yc.-r-^- n'-i'^r-ce undula— tions 8 short distar.ce from the tip of the "01111)0, which may be smooth ebly iindulated, while the imdula tions down the anter- ior slope, if present, are finer than those on ■'■>i'' lov.-den species; in addition ^he umhones are slightly lower, the limiile narrov.'er and the hinge not as be.'"vy. "^peci^'ens of this species in ^ai-^n'-'s collections ■-' -^e labell- ed "0_. mar:; land icus Conrad" fl), but that form is obviously differ- (1). Dall, v7. H., in Cu^ny and -11, Troc . U. S. Tini-. -^is., vol. 19, p. 529, 1896. ent. OcQ-grrenoe.- lower I.Iiocene : Bov.'den beds, 3ov/den Jamaica (Dall, 1902). 3HA33.VTELLI J^o i .->^.„,^uxiii , ^tLMoPIoSUS n. sp* Descri-^ti ' ...- Shell of mediimi size, hecvj-^, de^idedlv con- vex, t ■." rnclj? elong-ate, rno derate Ij? ineoiiilateral ; posterior dorsal mare-in eTioavated, abruptly ro\mded anteriorly, obliquely truTiCTte-l T^osteri orly, base slightl y emarginptf-^ri before the car- ina; imbones high, decidedly incurved, the apes flattened; es- cutcheon slightly vrfLder and longer than the limule, both moder- ately impresre''. ; poBtr--"!-;!- carina v/eal-r; running from the umbo to the upoer edge of the posterior trimcation a second, lov;er and broad- er carina present; sculpture of niiie concentric ujadulations in the umbonal region, "f^bp v^^ntrel few slightly crowded; on th'= anterior slope finer concentric undulations continuous almost half of the distance from the umbo to the ventral margin, the remainder of the shell smooth except for incremental lines; hinge "-^'^'^^ '^as::ive, the right posterior cardinal relatively conspicuous; inner margin of the VHlve smooth. ■Qinensions.- length 61 mm.; al-f-., '5 mm.; seraidiam., 18 mm. iAemarlrs_.- i'his species^ which is based on a single adult right valve and a very young right valve_, is very closely relcted to the Oak Grove 2* densus Pall (1), bi,it differs by bring propor- (1). Trans. V/agner ?ree Inst. Soi., Philadelt)hia, vol. ?, vit, 5, pl. 59, figs. 9-lf^, 1900; idem, nt. 6, p. 1472, 1905." tionately higher, more convex with higher and more incr^ryed iim- bones, more ercavate'l posterior dorsal marg'in, longer posterior trivficatiou, ricler posterior slope, more nxinierous and finer um- honal concentric undulations, \-hile the tmdulstions on the anter- ior slope are coarser, there "being no ahrupt change from one ser- ies to the other, such ts is very prominent on densus. 'the pres- ent form is readily distinguished from the associated lamaicensis by its rreater thielcness, more elongate OTitline, greater convexity, more escavated posterior dorsal margin, more incurve' umbo, the presence of concentric undulations on only the upner half or less of the anterior slope and the greater prominence of the right posterior cardinal. Occu.rrence»~ lower Kiocene : "Rowden beds, "Bovi'den, Jamaica. - 287 - Subgenus Orassinella Guppy. GRASS ATELIITE3 ( GRilSSIKELLA) GUPPYI Hall. Grasslnclla I'lsrtiniQensis Gmip-:, 1874, ^-eol. Hag. deeacle 2, vol, 1, p. 442, (oheok list), ex ;:Erte, non d ' Orb i p/ny , 1845. Grassatellltes (Grassinella) Gup-pyi Dall , in Gtip-,-)y and Dall, 1896, Proo. U. '3. I'at. Hub., vol. 19, p. 32 5, pi. f.O, fig. 5. Grassatellites (Grassinella) Guppyi Dall, 1903, 'Trans. V/agner ?ree Inst. 3ei., Philadelphia, vol* 3, pt. 6, p. 1476. Sesoripti jn.- "Hounded trigonal, flattish, concentrically costate, v.lth 10 to 12 lamellar ribs, much narrower than the in-, terstices. 'T-. 4.5, Ion. 1-.6 rn." (Dall, 1896). Tyoe locality .- Jamaica. Shell small, compressed or slightly inflated, outline irreg- ularly rounde-^ -triangular, moderately iziequilateral; posterior dorsal margin usually slightly longer than the anterior and sli=rht- ly e::Gavate', esrie daily ■:; ri o-ht valve, meeting the ventral margin at a sharp or subrounded angle; aiiterior dorsal margin straighter or slightly conve::, riutiding into the usually asymmet- ricelly arcuate base; lunbones relatively high, apically acute and compressed, slightly opisthogyrate ; escutcheon usually --^vider and more de^-ply i--pressed than the lunule; external surface of the ariult valve sculptured vath eight to sixteen sharp concentric lam- -280 - ellae, near the ventral mar.p-in are orowfled and occasionally? in- terrupted r '-olov/ the sharp edge of the lamella a lov; roxiy.ded un- diilation usually developed; hinge normal. Dimensions,- length, 4.8 mm.; alt., 4.5 mm.; semidiam., 1 mm. l^emarlrs . - '^n right valves the greater length and excava- tion of the v- ior dorsal raarrin is deoir^ed; some left valves are almost equilateral, but on the majority of them also the T)0st- erior dorssl mar,frin is longer and more angular at its distal end. The e^fre of the concentric laraell-e on the ventral half of the shell is usually more or less croder\ so that the lamellae have an irregular outline and may even he diseontinuo-. . "ear -^he vent- ral m.ar~in "ortuitous sma" ler lamellae are not Infreouently inter- calated hetvreen the larger ones. A slin-ht 'iepression is someti^f.es present in front of the posterior "liarrin, rarely causing the vent- ral marrln to he feehly insim^ateri. The Isr-e t valve has the fol- lowing dimensions: length, 6 mm.; alt., 5.6 :: . ; semidiam.., l.S mm. The recent West Indian 0_. gi^adalupens 11: d ' Gr"bi?"ny (1; is very (1). In de la Sagra, ^-Tist. phvs., polit. et natur. de I'Isle de Ouha, ITollusques, vol. 2, ^. ?-t, ^1. ?7, figs. 24-S6, 1855 ( ITrench ed, ) . close, hsving the same outline and the same type of sciilpture; the only differences seem to lie in the tendency for the recent - 289 •- form to he l^rp-er, more comnresser! and to hove hif^-her umlDones, fewer and more regularly spaced conoentric lamellae, il 'OrTDip-ny 's snecies ma 'he the sei-s as 2* l''''-malatug {0O''<-'^ ' "^1 ^"^ ) , "•'•icli occurs (1). -"-rrr. Acad. Pat. Sci., Philadelphia, vol. 7, v. 1?5, lOr^d; Pos. Kedial Ter. , IT. S., p. 44, pi. SI, fi^. '\ 1Q40 (as Astarte lunulata). in the Iliocene and '^liocene as v;ell as in the recent fauiia. '''he differences "between gupnyi and gaadalupensis hold for lunulatixs . The dorsal marrrins of the Oaloosahatchie "!. aou'-us Ball (?.) meet (2). loc. cit., p. 1479, pi. 50, figs. 1, '. , 1903. at a more acute angle and therefore the umbo is more acute; he- sides the shell is more compressed and the concentric lamellae more rounden. According to Dsll (190."^), Giippy's 0_. martinicensis d'Orhigny from the "Pliocene" of Matura, Trinidad (3) is gur^pyi . (?■!. loc. cit., 1874; Oeol. Kep-. , decade 2, vol. 2, p. 42, 1875. Occurrence.- Io'"er T.'iocene : Bo'.vrien he's, Bo\7den, Jamaica (Gup-ny and Ball, 1896; Dall , 1903). Pliocene (?). i:atura , Trini- dad (Guppy, 1874, 1375; Dell, 190:^). 01^.1 .::it::3 (33;. .;ia) 30:,.. . ^ :;aii. 3rasgatellites ( Jrassinella^ -oo^-denensis Dall, 1907-, 3. I7s,r;rner ]?ree Inst. Sci., Philadelphia, vol. 5, nt . 6, p. 1476, pi. 30, figs. 2, 7. Beseription.- "Shell small, thick and solid, -oltunp, sub equi- lateral, the aiiterior side a little shorter, "bea'is small, acute, reo-arved; liiniile and escutcheon lanceolate, subequal, veil impress- ed, smooth; valves with suhequal dorsal slOToes and -orominently arcu- cte "base, sculptured with concentric, Glo£e-;jet, flattened threads , which near the urabones are less crov^ded and slightly sharper; hinge solid, stron?-, normal. Hei^-ht, 7.5, lenp-th '^.'', ^lianeter 2.':' mm." This io readilj dis tinguiehed from J. . 'iixo; i b; its more con- 1. n , vex form, heavy jet smaller shell, and finer sculpture." (Dall, 1903 T^pe locality.- "Bov/den, Jama.ica, ■Jc 'n:ar>s.- ^'he characters of this species displ- "ir.ite' range of variability. She typical form is almost eoui!l 1 , the riorspl margins slorie r'irectl-" from t? e Timbc '" ■■;-!lri~ure c nsists of rather fine concentric r^v^&a. :'ii ■- ' "or^^is the post- erior dors'T.l raarc-in shows a tendency to be slightly concave and at the same time the umbo is not as full. I^he soi:ilptT:re may resolve itself into rather distaait, sharp rug'ae, thas a ?hing the sculpture of guppyi, but it 1 -er as coarse as in that species. Thr-re is also slight variatiiri r-i ;- ^ to ^': r. -^-f i_',--n ^■_ tion. ;9i - 2. bowdenr-nsic is chavactr-rized "bj^ ^' 11 size, convesitj;, suhequila-' ' "' ' ■ " ■■ - '- - . . ^ eparate it from the associate ^ p: irp'o^/i . The Qhipola 0. triangulatus j-.ll (l) is less inflated, hig-her, and its sonlp- (1). lo.G. ait., pv, 1476-1477, pi. 49, fig. 16, 1905. tiire is weaker an'"! more irregular, while on, 0_. tanious .Dall (2) of the Oak C-rove fauna, the low ooncentric undulations are obsolete (2). I ^ ::-;;, p. 1477, pi. 49, fi". 11. on the ventr^J. half of fm- ohell. Trpioal forms of the recent West Indian 0_. niartinicensis rVOrbigny (5) are snaller, more (P). loo. cit., . '38, pi. ."7, figs. 21-23, 1853. compressed and the sculpture more uniform. Occurrenoe. - L a:? e r M io c ene : 3 ow d en h e d s , 3 o w^ en. Jama i ca (Dan , 1903). - P-92 - OHAoSATELLir^S ( OrvA.JSIIIIiLLA) -ZEITUS n. sp. Sov'ldis- martinioensis Gabb, 1875, Trans , Am. Philos, 3oc., new !er., vol. 15, p. "52 (non cl 'Orbiprny, 1845). ■Description.- '^hell small, sli.'rhtly inequilateral, obliqiielj- rounded-tri angular , well inflated; posterior dorsal margin relative- ly short, slightly concave, aiterior dorsal margin longer, slight- ly convex, meeting the broadly arcuate ventral margin less abrupt- ly; umbones full, acute, slightly opisthop-yrate; escu.tcheon slip-ht- ly broader and shorter than the limule, both moderately im'oress- ed; advilt shell sculptured with fifteen to eighteen prominent evenly spaced rounded rugae, seuarated by narrower intersrjaces ; hinge normal. Dimensions.- Lenrrth 2.8 mm.; alt., 2,6 mm.; semidiam. , .9 mm. ^Remarks.- *his well-defined species is based on a number of valves. It is characterized by the longer antero-dorsal mar-in and the numerous, prominent, regular concentric rugae. In size nnd eonvezity it resembles bowdpnensis, but the oi^.tline is diff- erent and the sculpture more prominent and more regi-.lar. ^>. few of *:he valves are slightly larger than the measured type. Dall has describe'' a very closely related form, from the i>aplin and Vaccamaw, 2* dii-'olinian-.s (1) , but it is sm.aller, less iuflat- (l). Trans. 'Jarmer "^ree In.:. 3ci., Philadelphia, vol. '^ , -.it. 6, np. 1478-1479, ol. 50, f i rs . 5, 6, 190?. ed, proportionately GliP'htly lonrrer and 1->«r more .^'Ciite unilDGnes. Gabb's Santo Domingian martinicensis appears to ■belong- to this sneoies. QcourrenGe.- Upper Olip-ocene: Santo Donin.o-o (Gab-o, 1S7S), Lower Lliooene : Bov/den be Is, Bowden, Jamaiea. Superfamil;- 0 A R D I T A 0 E A . Familj? Jarditidae. Gemis VEIiSRIOAHDIA Lamarck. Subgenus Venericarciia s. -. YEKSRIGAHDIA SGABPJGOSTATA (Gu^p^:') Qardita soabrieostata ''uppy, 1866, Qiiart, .Jour. Geol. Soo. London, vol. S2, p. 29?„ pi. 18, fip. 10. Qardita soahricostata Suppy, C-a"bb, 187,5, Trans. Am. Philos. Soc, new ser., vol. 15, p. 252. Oerdita sosbrieog'I'gta Ouripy, 1374, Ceol. Mag,, ^^'^'^^'^ "^ , -"-ol. 1, p« 442 (check list) . 3ardita scabricostata Guppy, 1876, Quart, Jour. Geol. Soc. London, vol. 2S, p. 571, 7e:-.e ricarflia scabricostata (Guooy), Lall , 1907;, Tr . ;agner ?ree liost. 3ci,, Philadel :ohia, vol. 5, pt . 6, p. 1428. Description.- "Shell suborbicular, nearlj' as hi ' v/ide, Vv'ith about 18 regularly nodoselj/ muric>':te inipressed ribs; post- erior mar^rin nearlj/ straig;:t, forming an angle \7ith the ventral ma.r?in, vi^ich is rouMed; anterior raar?-ih rouided; umbones promi- .ent ; mar-ins strongly crenate, hinf^e irith tv:o teeth, of which the posterior one is long and narrov;." ' "■ , 1366). Tyoe local it:;- »- Jamaica. - 295 - --. Jhell small, moderatelj' inflcitel, decidedly' inequilateral, sixbquadtate ; anterior margin rounding "broadly into the base, base slightly curved and subpara'' "lei to the gently curved posterior dorsal margin; posterior lateral margin scarcely roimded to obli- quely subtruncate, joining the dorsal margin by a broad ciirve and -leetiiig the ventral margin more abruptly; i:anbones almost anterior in "Dosition, viell inflate'""', moderately.vn.de and high; limule small, •^eeply im-nressed; external siirface sculptured with nineteen to twenty-tv.'o ribs bearing strong rounde'" -f-^"= ■'■t.^'^ e •-'^'^'ii°s; the first few anterior ribs separateri by wider interspaces; the suc- ceeding :•'■ p to the posterior slope terraced on either side, the nodulated -oortion formi.xg a rounded keel, -"'" '^ interspaces being slightly narrov/er, beyond the T)OSterior slope tlie lov;er, terraced portion of the rib becoming obsolete, the ribs reluced in ;vidth and the interspaces co rresr)ond.ingly vrider; the last three poster- ior ribs suddenly wider and bear nodules that are more compressed at "^heir ends or even spinose and directed toward the posterior srgin; on the terrace:' ribs the nodii.les continuing across the terraces as obscure \mdulations; very fine concentric st: ' -nd coarser, irregular concentric elevations also - resent on the terr- :ces and in the interspaces; inner margin of the valve with very short, coarse crenulations. Mrienfe i oas . - lat. 19 mm.; alt. 19. E mm.; serai dia^.., 6.2 mm. - 206 - Reraarlrs«- -^'he small -valves of this stron^-lj- sculptured form are numerous. Ouppy proTDa-Qly did not .include the fir'"+^ ---' teriir and the last posterior rihs in his enumeration, for none of the valves at hand have less than nineteen ribs and the common nujnher is twenty or twenty-one. Occasionally a much smc'' " ■ '"^' rihs is inter- calated in one of the interspaces near the posterior margin. Young valves are more orbicular than adults, the terrace on the mediaji ribs is obsolete and the nodules on the ventral portions of the "oosterior ribs display a tendency to be m.ore scabrous. A- mong^ adult shells the characters are decidedly constant, except for a slight shift in either direction ?ith regard to the number of ribs. This S'oecies is characterized by its small size, subquad- rate outline, with stroi^ sculpture of the V. a"! ticoste.t-'^ ^-I'VQ, the terraces being prominent on the median "portion of the shell and the norlulations strong. Dall has described a Ohi^' Prm., Y. hadra (l), '"hich is larger, less quadrate, with more prominent 4 — — — — — — — — — — — — — — ___^__ __ _______ ____ (1). loc. Git., -op. 1429-1450, pi. 53, figs. i:j., IS, 190?. umbones, wider and less strongly nodula tei? ribs and the terraces, if present, wealc. The Tampa silex and Oak Grove V. him.erta Dall (2) (21. Id m, p. 1430, pi. 53, fi-. 1?. - S-">7- is larger, v.l fh fe'.ver, less oonspicnoiislj^ nodulated ribs and wider intersnaces. The Santo Dominp-ian specimens reach a size lar^^er th-sn. an 2,' of the _;o\vden ones. Oahh has criticized Gnppy's figure because of the pos ' of the va^ve anc. use the 'iro-oer number of ribe is not shown. It should be added that the up-^er anterior r:arf-i-. ' lically not as angular as is indicated on the figure, and since, on the figure, the terraces of the ribs are not differentiated from the nodulated keel, '■' :'ibi3 are v^rider than they should be. Occurrence.- Upoer Oligocene : Santo Doninp-o (Gabb, 1873; ^ruppy, 1874, 1076; D?ll, 1905)', Lower i.Iiooene: Bov;den beds. Bow den, Jamaica (Guppy, 1866, 1874; Ball, 1961.'?), - 298 - Subgenus Pteromeris Gonrad. Y-^V.-^RldAEDlA (PT. .- -13) AOAZ^IS Dall. Ymc-ricarclia ( Ptr-romeris } a carls Dall, 190r'', ^rans. ' — ■.ler ?vee Inst. Soi., Philadelphia, vol. ?, pt. G, p. 14:^4, pi. - ^6, ■--. 4. Desc^ription.- "Shell : , plump, inequilateral, the full "out rather low beaks situated near the posterior third; anterior end lonp-er, ohliquely produeecl, roujade'", posterior dorsal border descending' iiaiieh more steeply, subangular at the lower posterior termination; sculpture of about eighteen broad, flattene'l r^/lial ribs sei.iarated by narrow sulci and arossei by small, arctrnte, rais- ed threads, eonves' dorsal ly, the ends of these threads ■■-'ro.-ecti- • sometimes gives a punctate eff e :• ' ' " '"' -i; there is a small, narroY/ luuule and escutcheon anparently quite smooth; hinge normal, the lateral distinct; the inner margins sharply orenvl^fe , the ligament and resilium v/holly external. Length 2.5, f-^-^-i-ght 2.5, diameter 2.0 mm." "This little shell is '-p rdly 3 tyriic -9I ?t'-rom.pris, bi:it is poesesse -; of all the essential characters and nv ' regarde'"; a.s the precursor of the group. L^he posterior bea)rs are very oharac- t^rip.tic ■PpntT-'^s as v/ell as the -^ist^-ict latpmlF;-. ^t is the earliest knovm ancl smallest of the species." l-Jall, l^C"^), oi~\ q 'lype locality-.- ^':' -^en, Jamaica. Reroarlrs.- V. acaris is represented by a rather larrre num- ber of inrt-ivi duals. i?he sculptiire ooiosists of eighteen to t\^enty ■."•ell-def iner' ribs, ornamented vath lov; nodules, the r - ■'' '^^ <- s sepa- rated by narrow impressed lines. In addition to these ribs there is adjacent to the mars'in of the Innule a short row of re.^-nlar, ob- lique rugae that represent the nodules of the adjoining ribs. At the margin of the escutoheon a similar but shorter series is u.su- ally developed snd first fe^-' r)osterior ribs ere weak with the nodules somewhat roux-ded. ■'■'he lunule Is sharrjlj' set off from the sculptured portion, but the escutcheon, which is longer and narrow- er than the luiuile, is usuallj? less distinctly defiried; both are elevated toward the hinge in consequence of the decir'' '' Ickening of ■" ;;.rtn.ns, especially on the right valve. The hinge is strong, the ri?-ht valve v:ith an elonrated anterior and shorter posterior cardinal and a posterior lateral; the left v,'ith a broad, obt^ase, median cardinal and anterior lateral. 'Ihe height of the shell usu- a"^, ly e-TC eds the width. -i^his small, aberrsnt form is ou.ite riistinct, Occurrence .- T,ower Pliocene : Bowden beds, "Bov-'den, Jamaica. - 300 - Superfanily 0 ri a i,. a j ^ ,1 i J 'anii 1 J J h ami cl a e . Creniie Jn.i^.A (Linnaei's) Bnigui^re. j£x^.A Iirv''GLUTA Guppy. Ghana naoro-oh- 11a Oabb, 187", Trans. Am. Philos. Soo. now scr. , vol. 15, p. 251 ( as of Ohermiitz) ex parte, non Sroelin. Oha^:ia involP-ta '^uppy, IS 74, Geol. Kag, decade S, vol. 1, p. ".-36, pi. 17, f ip . 5a-o; p. 44S (chf-ck list). ?OhsTna involii'';a Gupp^", 1375, "^^tart. Joiir. 5eol. 3oc . London, vol. ?'2, p. 5?1. Ohana involnta Ouppy, Dall, igo.^i. Trans. V/ap-ner ?ree Inst. Sci,, Philadelphia, v^l. 5, pt. 6, p. 17-98. Descnl ption.- "Left (attached) va""'^ " "eep internally-, very convex e"^ternally, often spiral, completing a tnrn and a half, covered externallj? with r! istant lar?e foliaceoiis scalft-s more or less erect, Toetv-'een which are Bmall irregi''/' " ■^ ^^ -.rr-^.-r-- -.. granose ridges. Pdght v^lve patiiloi^is, ornamented with nunieroas close concentric sim-'oiis foliaoeous laminae. Umbones larpe, -Trorainerit, spiral, i.^arpin and laminar cardinal tooth erenate." (G-u-^py, 1874) T'-pe localit:;.- Jamaica. - 5C1 - "•This is a small S"OfOirs, attachr". 'by ^"^ -^ left vrlve, — Ith the scalpti^re of velves d isc;re-.x- r,t. I'he attached ve.l" ver:':iiciTl-ately verrucose surface with a few distaiit " low, radial spines, sotnetines oosolete; the free valve has lov;, flute :\ GO na en trio lamellae." (Dall, 19C:~). Shell SEE 11, thin to moderately heavy, outline variable, u;:ually suborbioiilar or elongate -siibovate ; left vrlve ^bed, irrc-ular, deeidedlj convex, with prominent, S'crong.'l; te um- bones; external sttrface soiilpture'^ vjith relatively coarse, slight- ly i::ibri(3atine' on -centric Isr.iellae, at intervals -orndroed and ele- vated into sl'ort scales arranged in more or less obscure radial series; irregular, interrupted, sv/ollen radial lines also present; right v-"^^."e conpresse'"' ^^t •'i-.^-T'p'^f^Ty ^-r.-^ir-^r-^ 1- t'" e -.'l re- gion; sculptured with usually closely-set, orojecting, crenulate^' lamellae; inner margin of right valve with fine, short r ions; on the left velve the ro"" o-^ R-f:--i c,f:i i p np.'^fiT ;;- remove'^ from the raarc-in, except on t e upoer posterior mar~in, and faint radial lines sometimes visible on the interior surface. Dimensions.- A left vslve : la'f^., 1*^ "T'i. ; r.lt., 14 ram.; diam. , 5.'^- mm. A right vslve; lat., 11 . 7 mm.; s.lt., 12.5 . m. ; diam. , 4.8 mm. Re'sr^'S,- Amonrr ^-"'''^ ^- ■ n-^-,--" v-i ir,-->r; o-p ■f:'!-i t =; prn^-^'-r: there are many that are la.r'~er than the t^. pi sculptu^ t were S02 - ":cL. V ", "^lie lar-est loft vclve Ik ' -^he foil ^: ■• : lit., 18 !:]iii., alt,, >-0,5 nr...; diani., 10 up. i'he sciilptT-U-e oi' z.c attache- , in this case, the left, vrlve is, as usual, irren:- ;il9.r, Ihe raclial scales, vrhich rarelj- vre of sr,oh ire aG ^~ be ternie'' spiiies, are often partially or completerlj obsolete, out the peculiar, irregularis? radial, int errupte^l , pxzstular sculpture Is usxially persistent. Gn ri.;rht valves, althouo-h the ornsmertati ->r. is rela"tivel;,' constant, the nunber of concentric lamellae, L.r.d there- Tore the spacing, varies, as well as the relative coarseness of the creniil atioiis , ~hich in a fe?/ exceptional casps are a.rranged in regular radial series. The nepionic shell is preserve'! on a few of the valves; it is minute, subquadrate, ":ith the umbo at the anterior enn, snd sculp- tured with sis or seven distant, regularly spaced, sharol;; raised and slightly recurved ooncentrie lamellae with intervening obscure, fine concetitric striae. The small size, "vermicular" and radially scabrous or spiny s ■Gulpture of the attache'', left valve and the numerous finely crenii- late*^ lamellae O"^ ^"'^'^ i-- -v-f: -r^i vo r.-re characteris-^i '^ -^r-t-^-'es of oecies. ihe Jhipolan J_. draoonis Dall (l) i£ lar;;-er and J-U^ . - . , • , • , ' • . • - • attached by the right valve; the sc \ e ::ielin, 1"9?, S^st. ^'^t., y-ii. ', . 3?G4. Qhama gitrea Crmelin, 1792, idem, p. 5305. ^liay.a niaorophylla Gi^iclin, Hanley, 1843, Descr, Gat. Rec. 3xv, Shells, p. H26. Oh ama ma o i-- o -oh .y 11 a. Gmelin, d'Orhigny, 1845 (?), in de la Oagra, Hist. -^is. , polit. y natur. de la Isla de Otiha, I-Ollusoos, p. , ( Spaxiish £••;' . ) . 0 h ar.i a ::ia c r o pli y 1 1 a Graelin, Reeve, 1846-1847, Gonoh. Icon., vol. 4, Qhama. pi. 2, fig. 6, pi. 8, Tip-. 6b. Qhama maei-ophylla Gmelin. d'Orbi,-.ny, 185-, -c- ._ ' ?. -'"^-^a, ''''2-^. ■ph:s., polit. et natur. de I'lle de Qiioa, I.olliisqxies, vol. 2, p. 565. (French ed .). Qhama macrophrlla Qhemnitz, Gahh, 187"^, ''^Jr-^r.s, Am. P'rilos. Soc, new ser., vol. 15, p. 251 fex parte). Ghama maoro-phi'lla Qhemnitz, Gahh, 1881, Jonr. Acad, Hat. Sci., Philadelphia, '"•'■"' —r., vol. ■-., ^j. 375, Qhama r;iacerophylla Gmelin, Dall, 1905, Trans. V/agner .Free Inst. Sci., Philadelpiiia, vol. 3, pt . 6, pp. 1405-1404. Description.- "Oh. testa rottxndata seriatim lamellata; - ?06 - raargine interno crenulata." (Gmelin, 1792, p. .'^504), Shell of ■'■■"^ ■''■ ' nm size, irregularly; traxisverselr '"^'bovate; at- tached hj- left valve; right valve moderately convex posteriorly-, compressed toward the anterior niar^'in; umhones large for the sise of the shell, prosogj^rate , foi-rning about one and a half whorls; external sciilp-ture consisting of irregiolar, more or less over- lapping concentric lamellae, crenu" . and pro'"^. at irregular intervals, sculptured with fine obsolete radial striae. Dimensions.- Right valve; lat., 27 mm.; alt., 23 mm.; di sri . , 8 mm . Remarks.- The collections at hand have furnished a single right valve that h?.s the characteristic features of the recent forms assignee" : ..pecies. Its occurrence in the Bowden be^s would be received with suspicion if the shell '^id not have the characteristic appearance of other Bowden specimens. Because of its much larger size, larger umbo, more foliaceous and "spinose" Ismellee bearing fine radisl striae, this valve is sharply differ- entiated from right valves of the ascociated involuta. As noted above, at least some of Gabb's Santo Domingian Ohamas are similar to this Bowden forsi. Occurrence.- Uprier Oli^^o'^ene: . ..':o Do (Gabb, in72) Lower Kioeeiie : Bowden -jt ;j, ^owden, Jamaica. Pliocene: li- mon, Costa ?dca (Gabb, 1881). Pleistocene: The Antilles and Oiiraoao (Dall, igc^). Recent; Tampa to Gur.-:c' / c :^ rta, /" '^:^azil in 0 to r87 fathoms. r?; ; '\ n Genus JrJEIITOO'-AI.LA Fischer. 3GHIi:0GHAi.ii ^ ..i^iUATA uall. Ghsma aroinella Guppy, 18,6, Q.iiart. Jour. Geol. Soc . Londoi-:, vol. 22, p. 204. (non linnaeus, 1767). Ghana aroinella C-abb, 1875, Trans. Am. Philos. Soo . , nev: ser., vol. "! " , . Pol (non r.innaei''S, 1767). Ohama aroinella S-uppj', 1874, Geol. i--ag. , decade £, vol. 1, ■!. 442 (checli: list), e" parte, non linnaeus, 1767. '-'hama aroinella Gu-^pjz, 1876, f^-'^a.rt. Jour. -eol. Soc. london, vol. r.':, p. 531 (non linnaeus, 1767), 1] oh i n 0 c har.i a an t i n ua t a Dall, 1903, Trnns. '.Tagner Free Inst. v'5ci., Philadelphia, vo^ . "^ ■■it. , m. 1^0^-1405, pi. 54, fip-. 9. "DescriotioTi.- ''Shell lar^-e, subquadrat-^ ^ vl th an almost ob- soletel^' rectilinear base, sli^c-htly arche'-"- posterir: " "-srsal edges, and excavate' anterior end; valves less oonver- in 22* aroin'lla an''' with less ■orominer'f^ " • ■-i i.-cn.o-^^ ^ impressed lunule; the nu-vher ' "rom t -tvvo to thirt^'-one, low with subequal ii.' , ' . very short and f^cslp-like eTrce-^-'" (^^^ -■:■' - •■.-.-.■i ^ r^<=-'^>ian rib; where thej" are tri- _ 308 - angular an'''' sorrir- ' ■' -'" t ■--■■- '--■•>- thai, ^jix tlie rest; '■-■^-""'^-: - more pustular and less regiilar t?ian in S. aroinel la. T'enc;th 50, hei,o:bt 48, '"liameter alDont 40 rm, exclii.sive '^f tl"ie spines." "Sh" o t;-'t.-ul._o '.;. cii oomparei is seen ' ^•■f-"/: 3t. from the t;rpe of the geniis with which it was confused by " " is reallj" more like the Pacific er^eci , Q, californica DallJ '-'hich has nearly as many ^lju ;j-.'' ' ^ -• . ._ ^ ,. .. ii.; ' ule and long, cylindrical spines." ■'All species have occasional individuals which have the spines and even the rihs nearly ohsolete. Guppy's "'^''■^ian speci- men, and a valve collected in the Pliocene o:^ ., Jost? Tiica, hy Oahh, are of this character, hixt as it is more an individu.al mutation than -j. urue variety I shall not ap :;1„ an„ iistixictive name ' t o i t . " ( D^jU , 1 9 O5 ) . Type locality.- Bor:den, Jamaica. Shell larre, .:iai;aive, equivalve, decidecf" ilafceral, outline subquadrate ; dorss" in scarcely curved, rou.-d.ino- into the fently curved "posterior margin, ''.'hi eh passes m.ore abruptly into the truncate:' base; anterior marjin oolique across the 1" "''■ ' insinuated tt the base of '' " le and then abruptly flexe(! ou-t7;ard; umbones anterior in -vosition, m.oc'erately inflated ai-id modera'^ely high; lunule large, deeply impressed, its \ " ' ' ' ^"'- tlon raised toward the margin; e temal sitrface soiilptured with - T09 - tweiitj; to thirty lov/, roixi^ded ribs, separate"! by intersoaees of v-.j- +;-j^g .,c;.i;ie \7idth; on tu" osterior half of the shell the rihs small, hnt increasing in width toward the center of the shell where there is a single prominent rih; on the anterior h:^if the ribs fe!7er wider an?. "— •~^'-- -nd decreasing in size anterior- ly, bixt near the marp-in of the Irnule again becoraing larger; on the dorsal marp-in of the right valve one or tv/o more or less irregular ribs, rnn.ch more ororninent than those i. my lately suc- ceeding, present; ribs ornamented vath short, spines, most promi- nent - lar^e meciisn rib and on the posterior ribs often teJcing the form of small irregular nodules; ii.'';tT;:3;juoes and lun- ule irregularly pitted; concentric sculpture of irregularly dis- posed, slia-T^-tly imbricating lamellae near the m.argins, the lam- ellae continuing across the limule; inner ventral mar ""in of the chell slightly undulate "" by the anterior ribs. Dimensions.- Lat. , 52.5 mm.; alt., 5S mm.; semidiam, , ,"^1 nim.. Puemarks.- ihe large, massive shel?.s of this species are a very conspicuous element in the fa.u.na, bein<^- equalle''. in sise only by some of the larf^er snccimens of Area halidonata. b^it in '.veness xmsur'^assed. x'he prominent irregularly spinose rib, or ribs, adjacent to the dorsal In is a constant feature on right valves, but is not -oresen'. ';he other valve. Som.e dist- ance from the dorsal m.argin there is often present a shallow, but well-defined, groove. The portion of the shell betv/een this - ."^10 - groove and 'iie prominent median rib is slip'litly raised. 'i'racGS of reddish brown ooloration are visible. ,,.,. .'..^. l..;'-pvT-,r sixrface of one of the valves. E. arcinella li. '• fl) o?oiirs in the 'Jest Indian waters (1). Linnaeus, Syst. Hat., e"^. IS, v, 11?9, 1757; Reeve, Oonoh. Icon., vol. 4, -'^1. 5, "^■~. rea, b. in depths up to twenty-six fathoms and is also fo^md in tbe Oal- oosahatchie aiid V.'acoainaw Pliocene. In a:''diti'^n to the differences discussed above, arcinella has fewer, broader :•' "^ eh larg- er spines and the ventral margin is decidedly affected by the ribs. T'^e yoimg of antiouata have f ewi r ribs than the adult and relatively longer spines, so that they more closely resemble the recent snecies. It is an interesting fact that, as mention- ed above, the 3ov;den form is more closely related to the Lovver Oalifornian E. calif omica Call (2) than to the recent V.'est Indi- (-). an form. The Santo Domlnp^ian s-necimons have in general less promi- nent radiale ''— entire t; iu-;ace iwjre deeply pit'i'e-. It £should be stated that Iiall'c figure does not present the shell in its -oro-er -oosition. - 511 - Occu.rrer.ce»- Upper Oli^'ocene: Santo Domingo (Gup-oj/, 1866, 137-1-, 1375; Gabt, 1873, Dall , 190?:). Lov7er T'locene : Bow- den beds, SO'^den, Janaica (Guppj-, loo6, 1874; Dall, 190S). Superfamilj^ I U 3 I i: A 0 2 A . ?ami 1;,' Luc ini 'i ae . Genus ^ODAI-IIA ooopoli. Section Godakia s. s. OODAKIA SPIITUIOSA Dall. Godalria spiniilosa Ball. 1905, Trans. 'Jagner ?ree Inst. Jci., Philadelphia, vol. ."^ , pt. 5, pp. 154G-1S47, pi. 5S, fig. 19. .Description.- "Shell iiearly orhiciiLar, moderately and regulai"- ly conve:-:, solid, v;ith pointed, low, ^-'rosog;.' rate beaks; lunule sr.iall, deep, cordifomi; sculpture of sms" : , low, fla"^tish, indis- tinct radials with slirhtly excavated, narrower interspaces; these are crosse^T by iixlistinct concentric threads, incremental lines, and occasional ridges due to restii:g stages; at vv'hat would he the intersections, if the concentric sculpture were better developed, the shell shows snail, S'^uarish nodulatiori:- -'^ich towards the ends and dorsal margins become minutely spinulose; the right valve has the hinge well developed, the anterior lateral large and strong, the -oosterior obsolete; the posterior cardinal slightly groov' ' • margin with traces of crenul ati on anteriorly ; scars normal. -'eight 27.0, length ?9.0, diameter 12.0 mti." (Dall, 1905). Jy-pe loealit;;.- -SovTden, Jamaica. ?.en£r::s.~ This species is imrepr esentecl in the material at hand. The concentric sciilptirre is recog-nisahle p.s noclnJes, erod- ed from much of the surface of the type, '"hich are most -nrominent anteriorl5? and tov/ard the margi_ ^omes pustulose, hut r , ]- spinose. The radials are >'->.-'a-!^ -...- -eii defined as is shown on the figure. The elm racteri Stic features are the pustulose sculpture aiid sr.iall deep lunule. 'Tl^.ere is no ■'" —iaility of ^-^^ ■^■^'^•i-- -^-i-^*- species v/ii3i the recent .Vest Indian 0, orhlc:iLaris 'Linnaeus) (1), which ran5-9S hack to the Pliocene, hecause of its much smaller (1), '];,':5i;. Tat., aa. 10, p. ooc, 175S, (as Venus or oicularis) ; -Luc in a ti;?srina I^eeve . Oonch. Icon,, vol. 6, Luc iiia . :~1. 1, fio,'- ^, IS 50 (non Linnaeus), size, more rouixled outline and less pronoxmced radials. Dall (2) has suA'gested that Guo-n^/'s citation of L. tip-erina from the"MioGe:"ie" ("). loc. cit.. of Jamaica mav refer to a large species of Jodakia from a limestone at Olairnont, St. Ann's Parish, Suppy, however, ;loes not seem to have recorded ti ^erina from Jamaica, although in IGV-l (5) he cited - 514 - that species from Haiti Santo Domingo and Humana, and ap:ain in 1876 (4) from the former locality; Gabb also recorded it from Santo Domingo. Co). (5). Geol. Hag-., decade 2, vol. 1, p. 44S. (4). Quart. Jotir. Geol. Soc . London, vol. 32, p. 550. (5). Trans. Am. Philos. Soc, new ser,, vol. 15, p. 251, 1873. QcoTirrence .- loxver Miocene : Bo-;den beds, Bowden, Jamaica. (Dall, 1903). - ^_- - 00-ui\KIA LOIuOlTLA n. sp» Desorj-ption.- Shell soall, suborbicixlar, weakly inflated; more produced siid more convesly roimded anteriorly"; lunlDO Ioy/, acube; limule narrov;, moderatels? impressed; external siirface seulptitred with about thirt37-t:vo strong radials of inconstant r:idfh, separat- ed "by narrov/er interspaces; the rihs vath relatively coarse nod- ules arranged along usually eq^ially spaced con-:? entric lines, the nodules heconing compressed .■^•i''.d sharker toward either end; right valve 'vTith tro cardinals, the posterior larger and obscurely bifid, and an anterior and posterior lateral, the posterior somewhat obscured by the lig-ament ; inner margin of the valve feebly crenu- laterl; the interior with obscure radial markings. D intensions .- Lat., 14 ram.; aLt., 13 mm.; semidiam., 2,5 rr.i. Remarks.- G_. lo^nonea is known from a single ri ^'>t v-^ve. It is characterized by its strong sailptTire, both the radial and the concentric nodules beiag sharply chiseled. The radials pre slightly inconstant in width, osriecially tn ■■■■•rd either end, The sculpture is unsually strong for the section Jodakia s. s , , but the shell is larger and more cora^jressed than the average Jagonia. Occurrence.- Lower Iliocene : Bowden beds, Bowden, Jamaica. Section Jagonia R^aliiz. OODAEIA (JA&OITIA) PERTEKLHA Dall. Godaliia ( Jagonia) pertenera Dall, 1903, Trans. Wagner Free Inst. 3ci., Philadelphia, vol. 5, pt. 5, p. iri?, pi. 51, fig. 4. Description.- "Shell rather large, very thin, v/ith the surface more or less irregiils rl^- indented, as if from nestling; anterior end larger, attenuate!, posterior end more plump, ob- scurely yertically truncate, beaks low; lunule lorig and very narrow, not deeply impressed; surface finely, cloeely, concen- trically, and radially striated, but so feebly that no obvious cancellation results; hinc-e-nargin narrow, hinge-teeth feeble, "-Aie laterals in the left vsl^re obsolete or absent; scars lucinoid; margins sometimes obsoletely flutedi Heigl': 32.5, length 35. (, diameter 13.5 mm." "This S"oecies is not a characteristic Jar-onia, but ' ^ lear- er to this group than to any other." (Dall, 1903). Type locality.- Bow den, Jamaica. .\:e marks.- J_. pertenera is represented by a niunber --^ valves, the lar?rest being more or less fragmentary. It is recog- nize'^ b:^7 its somewhat elongate outline, feeble inflation and ir- regular surface v/ith v/eak sculpture. - 517 - Ocourre:-ioe.~Iov7er riooene: Bo^vrien beds, 3ov;den. Jamaica (Dall, 1905). - ?]_8 - aODAIQA (JAGOillA) OUPPYI n. noni. Lucina tey:tilis Gupp-;, in Gupp^- and Dall, 18 9o, Proo. U. 3. L^at. Hiis., vol. 19, p. 225, pi. 50, fig. 1. Oc^-akia ( Jagonia) testilis Guppy, Dall, 1905, Trans. V/agner Free Inst. 3ci., Philadelphia, vol. 5, pt. 6, p. 1548. Eot Incina te:--tills Philippi (= QodaJ^ia ( Jagonia) te:-tilis) . 1850. Description.- "Orbictilar, occasionall-; a little irregular in outline; decussate by somewhat irregular fine radiating and con- centric lines; mar^-ins dentate. Diameter, 11 nmi." (Guppj?, 189G). Type localit: . - 3ov.-den, Jamaica. Shell snail, thin, surface usually irregular, v/ell inflated, width exceeding the height, slightly ineauii ateral, being more produced anteriorly; anterior dorsal margin short, direct or slightly concave, posterior dorsal riBrn-in longer, straight or slightly conve::c; broadly rounded anteriorly, vertically subtrun- cated posteriorly; iimbones tumid, moderately high; Imiule small, narrow, moderately impressed; aiaterior dorsal area poorly defined, posterior dorsal area depressed, noi'^etirfi s causing a slight sin-n- ation of the niargin of the valve; external sculpture of numerous vreafc radials of irregular v/idth, crossed by lov;, concentric lines of various v;idth and irregularly s'oaoed increraentals ; on the dor- sal areas the radials absent or pocrrly developed; cardinal teeth 719 - weak; on the left valve the posterior lateral or both posterior and anterior sometimes absent; ri??ht laterals usfially present, but sometimes wefsk; inner nBr.^ln of the va]ve finely crentilated. Dimensions.- Lat., 14.2 mm.; a3.t., 12.5 mm.; semidiamx., 3.8 nffii. Remarks . - The concentric sculpture as preserved is irregul- '■■vli; developed since most of the valves are v/orn; there are present however, irregularly spaced concentric lines of varying width and sharpness, usually absent on the median dorscl rep-ion, as v.-ell as incremental lines. xhe fine radials are usually preseiit over the entire disk, ezcept in the umbonal region; they too are of varying v^idth and -^Tom.inence. Bo:".: . ''S of scul-^oture are usually conspicuous enough to produce a reticulated effec'-. Some varia- tion is noticeable v/ith regard to aonvesity, but in general the craracters are quite constant. This is an abundant form and various gro7rfch stages are repre- sent e'', the valve measured being one of the largest . The small size, slig"-tly elongate outline and fine rariial sculpture are characteristic features. Dall noted the fact that Guppy's name was pre-ocGupied, but hesitated to propose a st^ecific name since he doubted whether the "r^~ro^ oouJJ-d "'-'-• ^'^^ -^if ically differentiated from pertenera. The present form is, however, mxioh more abundant than pertenera and presents constant 'Tifferenoes in being decid- e-^ly small, more inflated, less ..1 .^ated, with more cons^:'icuous scu-lpture and definitelj? erentilated internal raarg'in, Tae name is 3'iven in honor of I'r. 3, J. lecheraere Ouppy, of Port - of - Spain, Drinio...:-'. , vhan \~hom there has been a no more orolifio contrihutor to the oaleontolog-;- of the V/est Indian Tertiary terra.'. CGcnrrenoe«- lower I'locene : - , Ten, Jamaica f&uppy and Dall, 1896; Dall, 1903). '21 GODAZIA (JA.^rriA) YZIIDHYESI Dall . Jolalcia ( Ja.^onia) Yen drye si Da 11 . 190?, Trsus. V/g-gner Free Inst . Sci., Philadelphia, vol. ?, :. 3, p. ISdG, pi. 52, -p^ r. ( Sun- tiTre , \-i th finer and more thread-li"'-e radials, plumpc"' ^"' ' ^\ --in_,,, o]-,g]_i^ j-t j_o a'biindant in the 3ov ' arl, fro; ^r/hich it was collected by Henrj' Yendryes, I^sq . , v/ho sent it to Kr. _ _rad suhseqnently hj' Messrs. '-Tr-nderson and Simpson." 'Dall, 190"). T;; -J looality.- Eo7.-^en, Jamaica. Shell small, veil iriflated, ineaui"'.ateral, the lower portion of the anterior margin ohli-^uel;" — ^uccd; ;imbones tiiniid, mod- erately prominent; lunule smal^J-, deep; dorsal areas poorly defin- ed e-'cept for the diffe-; 'n ce^" ; 1 sculpture of numerous, fine, sharply dexi^ied radial;.; u^pically several fas- cicles, including iisually t'.70, but soreti es three radials, pasn- in^r :^rom the umbo to the margin, v.l th finer, lo"'er radials inter- calated between the fascicles; the more prominent radials forming the fascicles oceaslonally toward the nB.rjin ■becoming less promi- nent ar.^. '^■i^'h"-"--] ■'•--> ■^'•-1'- .-^fv- C---0 . gometir'--^ r^^ "•■""■ ^les present, with some rao.ials merely more prominent than others or all suh- equal; the ra^lials hear' jntinuous rows of :- , prominent nodules, continuing acrose ■^'-'^ Interspace; . " -"^'?.s as raised concentric lines; anterior dorsal area bearing a few v/eak radials; anterior portion of pos^terior dorsal area withont radials, the remainder w-ith ' ■^''' "--■■■'ialo .cu :':.:! .-.1--.^ -t.^.-,,,,,-: .- ^ i^arrin, a very narrow area adjacent to the nar,?-in being almost or entirely" smooth, hut not depressed; hirjge strong-; inner narg-in of the valve finelj' cremilateu. Dii?. ens ions,- Lat., 8,2 mm.; alt., 9 mm.; semidiam., 5 mm. I? esnr '-•:■.- This species is the most ahim'^ant of the Iticinoid for^'iG, a;:iOii^; v-^iiuL it it: ooiicspicuoac;, Liespite i r^ .^..icll size, be- cause of its sharply reticulater) , strong sculpt . ." e sculpture is, hov/ever, very variable, v;ith almost all r: ^^ ■'""'' at io"'£! from fas- cicles of prominent radials, separated b;^" ii:.ier ones, uo oubcqvial radials. On young shells that have fascicles, the individual radials constitutinp- them are fused for a consifJerable 'Tistance to":ard the umbo and the finer int er^/ening radis.ls are more often absent than on adults, 'Ihere is some variation in the dec inflation and in the coiweitlt;; of the aiiterior margin. The Ip.r^- est valve at hand has the follov.ang dimensions: lat., 9 nan.. alt., 9,1 cmi., cliam. 2.9 mm. Yoxaig valves on which, the radi.?.!?' are siiheqiial rm;,- possibly ■"0 9 confused with certain form^.^ oJ :.::« .-GconiiDani^ing- jhacoides (Be71ucina) act inns Dall, bxit that species is 1- nilateral, with friller imihones, coarser and more regi^lar radials, concentric sculp- tx-ire consisting of sharp, thin lai^iellae, a wider limule, an es- cntcheon, weaker cardinals and more elongate laterals, especially the posterior, Dall notes that this species in the Guppy collection core the label "Liicina -ecten var. antillarum." 5-a,bb's (l) Santo Domingian. lucina antillariun P.eeve. which ^1), Trails, iim, Philos. Soc, new ser., vol, lo, p. 251, 1873. Dall placed in synonymy, is more like the recent arxt illariim. being more roimde'', more imiformly -:, with broader mibones and weaker sculpture. Occurrenoc- Lov/er r.ioeene: Bowden beds, Bov.den, Jamaica (Dall, 1903). -■?A - Genus I^'!^TA:]A TTirton. Sectioi- Lyrtaea s. s. ■'-':TAEA LILIOICI Dall. "::-rtaea linionlg-ga Dall. lOn."^ Trans. V/agner ?ro^ ^.-... b. Sei., Philadelphia, vol. S, Tot. 6, p. 1358, pi. 52, fig. 10. SeF^oription.- "Shell small,, thin, suh equilateral, somewhat longer than high, only moderately convex, though hardly com- pressed; healcs snBll and low; liinule depressed, narrow, suhlance- olate, small; surface gov ere "^ v^ith fine, sharp, thin, elevated, concentric lamellae, separated "by wid r interspaces and m.ore elevated near the dorsal margins, eSTeoiallj; behind the beats, where in ■'Terfect specimens five or six of them are --■-'^-■'— q-"' ■^ s small leaflets, "rhich, however, are usua'^ly broken off; hinge with a single rig^'t am t\70 left cardinal teeth, the laterals obsolete; sop'^^ r-^rmal; the margin of' the valves entire. Alt. 8, Ion. 9, diam. 4 mm." "This species, thouQ-h very similar, is more elongated, less elevated, and more densely lamellose than "". carta [ponr^d (l)- (1). Am. Jour. Gonch., vol. 1, pp. 8, 139, 212, pi. 20, fi:^. l--f, 1865. Eocene and Vioksbui', j , ?rom the II, -oristiphora Dall and Sinip- son fl), the recent representative of the group in the V/est (1). Bull. U. S. Pish Oonm., vol. 20, "ot . 1, p. 495, ^^1. 55, figs. 4, 5, 1901. Indies, it di"^"" ""- by its more quadrEite-elongate form, thinner shell, and more delicate and sparser ooncentrie lamellae." (Ball, 1905). '?^:-pe_ looalitv.- Boi^rien, Jsrcaica. The anterior dorsal marp-in ort, straight or slightly excavate:', direct or with a ^ ' . slope and aoru-otly Joining tlie ohliquely suhtrinic ated upoer anterior lateral margin; while the posterior dorsal marrin is longer, direct or slightly; con- vex and passes ahruptlj' into the vertically tnmcated posterior end. Her!sr"'rs.- This species is quite abundant in the material at hand, the largest valve measaring 11.9 niri. in latitude, 11 mm. in altitude and 2.2 inm. in diameter. Variation in inflation is displayed, some of the valves heinr more than moderately convex. There are also contrasts in the concentric sciz!J.pture , vrhich ranges from hTit slightly elevaterl lamellae to much more consnicuox^s lam- ellar fring-es; m.uch of this is, however, due to erosion. The lamellae are always sharp atid closely siaaced. Some valves from •iiio - which the lamellae have "been removed show miGroscooie vermiciila- tions, like the eanrotonectes striation of certain 2ectens, v&ich reflect li?-ht hrilliantly. ■2'ae s pe ciiiiens from limon, Josta .-tica, are not cuite as larrre as th^se from "Bov^den and the sciilptiire is slightly finer than on the average 3oi"den form. Oecurrence«- lov/er Miocene: Bow den beds. Bow den, Jamaica (Dall, 19C3^. Pliocene: Limon, Oosta Rica (Dall, 1905). - 3?. 7 - MYRTAx... ^i:OLA n. sp» De script ion .- Shell of medium sizp, tli'..., , .,..^^ .,. 1.., .,i. ^T , sutiorbicular; anterior dorsal margin short, slifAtlj^ e::cavaterl, upper portion of the anterior lateral marsrin obliquely truj-^catecl; pop-^'^-r-im- rf,",roc,-i margin higher than the anterior, longer and slightl^^" convex,, posterior lateral marn-in suhtruncated in the region of the dorsal area; umhones "broad, lov/; Ituiule linear, mod- eratel;.' i "^"■-'e'^^ed; anterior dorsal area poorlv define:., j^^osterior area more prominent; external surface scnlptured with nuxaerous, fine, unequally space- and often obsolete, weaklj' elevated con- centric lines, becoming more prominent and sublamellose "- "^he posterior area, between the concentric lines over the entire sur- face of the shell obscure vermicular radial markin 'esent; hirjge of left valve edentulous except ■^■^v a faint suggestion of a single cardinal; rirht valve not known. Din^ensions.- "^ t., R4.5 mm.; alt,, S2.g mm.; semidiam. , 6.3 mm. Remarks.- I'his species is described from a single left It is readily distinguished' from ]^, limoniana by its mixch larger size, greater convexitv s.n -: 1«6S lar.ellar concentric sculpture. Occurrence .- x-ower Eiocene : j^ '-en beds, Bo^vden, Jamaica. - 520 - Section I'lulopia Dall. ITRTAiiA { jjUlO-^.-x; . -.i-li^ L„-i-^x ^all. llyrtaea (Eulonia. ) verralciTlata 'npll^ 19^5^ Tra-.s. Tagner ?ree Inst. 3c i., Philadelphia, vol. 3, pt. 6, p, " ', pi. 52, fig. 5. ^^yrtaea (2ulonia) Termicnlata Call, 1915, "^:ill. U. . . 3., :.o. 90, pp. 15C-ir7, pi. -^, ■■_ ■ . -' ' . Descrlpti on.- "ohell rosemhlinp- !;^. s.g.f-rinata '^gll. hiit shorter and more rounded; moderately convez, suh equilateral, the anterior end slightlj^ longer; healrs Ioa'/ and inconspicuous; lunule narrow, eoncaveljT e* ''ja.vateri ; the esortC'ieon l1:-.-.^.r, lo-.-.n-j both houjiided externally by a serrate carina; 1 i gauient ai-y £:roove about half as lo.g- as the escutcheon; surface ' ' slir-htly ele- vated, thin, concentric lamellae, the in''-prpr,r.?eF' -"adially sculp- tured v/ith close-set vsrmiculate threads; hinje v;ith the normal cardinal dentition and distinct right laterals; adductor scars rather small, the interpallial ar.. ^ .luiotat . .'/' . .o, low-. 7.5, iiam. 3.5 ram." ( Jell, 1905). Type locality.- low den, Jamaica. The anterior and posterior rinr<^:r.i v,,,-,-c-ins are of vi rt" '■"'■' : the same length; b'lt the anterior is oioderately to decirledly con- cave, v.hile the posterior is slightly- convex and steeper. "29 ?.er:iar--s,- The disti:: ing features of this species, which d- .. epreseritation, are the relativel;' ■'' ^ .■-^^-rh -^--^-r-^li' r ised concentric laniella.e and the somewhat ir , :■]?: rad- ial-s in the inters^naces. Some of the valves are "roportionatelj" '1 "^he one figured hy Dall. ?!:? ' ' ' ' -"-^ •■^onee heti^/een this form and the relate" H. sa.firinata Dall (1^ . res- ent inhahitant of the 'i7est Indian waters, is pointed out above. (1). "Biill. LIus. Gompt. Zool., vol. 12, pp. 255-2G6, 1886; Proc. IT. S. ITat. Kus., vol. 12, -. "^5?, pi. 14, ^ - . ^1, 138-9, ( as Iiioina sagririat a ) . The single Tampa silex Sulopia that v/as re 1 to this species is no longer in t-n-^ T^ational K-nseiun and therefore no material is avails'-'' jr u j..:-c.ri;;;'ju. Occurrence .- r Oligoct ,, : ? Tampa silx •, Jloriua (]Jd.ll, 1903, 191'^.); Lower I.'iocene: a^Ov.a'-ii □elu, jqv, aen, Jamaica (Dall, 1905, 1915). - 7^Z0 - UYRTA^A (iULOPIA) li'UI^CATA Jail. Itl.yrtaea (.EiUlopia) f lu-eaba Dall, 1903^ 'Iraiis. iVagner Free Inst, 3ci., Philadelphia, vol. 3, pt. 5, o. ]' ' , 1. 5?., Desoription.- "Shell thin, rotuided, moderately eonve-, suhequiT.ateral; "beaks Icy;, inconspiouous; lunula loi ^ rrow, moderately irjpresscd, esoutcheon almost linear, oordered outward- ly carina; surface near '-he "beaks with delicate, ;;, sli'yi:bl^ '-rlevated concentric linec --•■'■> he cone alr.io " '-c over the middle and hssal portions of the disk; radial "" ''vj:e of f:' , lo°e-set, rather flattish threads, w'ich t j the n:""" ■ _ ■ ' _ '" -" ■" ■ . ci rather widely divaricate and some- what irregular sculpture; hinge delicate, the rin'ht ~ Is feehle, li-arientary p:roove r^istinct, rather short; the adductor sears Icu-ge, nor;:ial ; the .nargins of the valves entire. Alt. 11.5, Ion. 17', dian. 5 mm." "Thi'' is larger, more delicate, and thinner than if the group." (Jall, 19Q3). Typo 1 0 "■ al i t ;: . - Bowden, Jsnaica. The si: ell is "broad' r than high; the antero-dorsal niargin concave, the postero-dorsal mar?;in straight, Ic- •, " 1th a steeper slope, so "^hat the anterior lateral ore con- - 7>7'1 - vei- than the posterior. Remarks.- A few valves of this readily reoopnize^, 'fomi ere present. I' ' jharacterized "by its delicv' , 'Lstaat son- centric seulptiire aad weak, niinerous radial s that rather abrupt- ly '^-'.''-e"''0-'^.or sal rnargin excavated, po;/ - lorsal almost straight, sloping gently, meeting the vertically trimcat- ?■■! postero-latersi margin at an angle of abont 1"0*^; roimcTed ventrally and anteriorly: nmhohes low; Ivinule small, feebly im- pressed, cordate; posterior area poorly define':''; e"ternaj sur- - face sculptured with fine, thin, elevated concentrio lines, erod- ed from much of the surface, and faint su^ges-^-^' '-^ • ^' o-^ -^ine radials ' of varying width; hinge weak; inner margin of the v-lve entire. Dimensions.- lat., 8 mm.; alt., 7,5 ram.; semidiam. , 2 rnn, Hemarj:o.- -i^^is species is described from one ri^ht valve. The radial sculpture is very feeble and toward either end is ob- scurely divergent in a mar^ rmewhat similar to 1.. furcata. From that species oronta differs by its — "--J^er cor-vesity, closer con- centric lines, weaker and finer radials, wider but shorter lunula and the absence of an escutcheon. Because of the feebleness of the radial sculpture oronta may be confused with ^. limoniana, but the new species is more inflate"', with a wider and shallower luji- ule and much less conspicuous concentric scTilpture. Occurrenc" .- lov/er I'.iocene : Bowden beds. Bo. ' , Jamaica. Genus PHAGOIDi;S Blainville. SulDf enus ?hae nid.es s. s. PHAOOID::3 DOMIKGEKSIS Dall ? Liio ina ' j ama 1 3 e n s 1 s Cabb, IS?'^, Tran^:^. Ar.:er. ?hilos. Soc, ne?/ 3er. , vol. 15, p. £51 (non ^======.: , ==!i=F: ) . Phaoolcles domingexisis Dall, 1905, Trsus. V/agner ITree Inst. Sci., Philadelphia, vol. r^ , pt. 5, p. \7J.? , -1. 50, fir. 11. t Phaocides aorriin°rensis iJall, 1915, 3ull. u. ii. icat. I.jj.s . , i. u no. 90, p. 137. Desori-Q'-i-n.- "Shell closely reserchling 2, peotinat'ds ( for which it has oeen tal^en by Guppy), but smaller, more inflate", with the Aotch in front of the anterior dorsal area rinre indent- ed and angular, '':' ^nc entric lamellation mo/e distant and more evenl" spaced, and the -nosterior dorsal area shorter in propor- tion and more triangul;::^ . .».lt. "1, Ion. 54, diam. "! '^ -^n." . "This is V7i th little doubt the Oligocene precursor of P. pectinatua (pmelin (l)J , and was regarded as identical with it (1). Syst. I.'at., vol. 6, p. 5256, 1792, (As Tel'^ina peotinata) = I'j-cina namaicensis lamarck, 1313. by Gabb and Guppy." (Dall, 1905). "■'^4 - 2ype local it: »- Isl&nd in Lake Henri quillo, :5anto l;omincro. Hemarks.- This species is not represente^-l in the collec- tions at hanrl. The type is silicifierl and has scni ■■-'*: -re con- sisting of rather riistant more or less lamellar coneentric ru.gae with finer, somewhat irregular intercalated secondary rugae. The single, badly worn fragment from 3ov:den in the i^ational r.-useum collection that has heen referred to this ; ' -s lias no indication of secondary concentric sculpture and the primary rnc-"e are closer and not as lamellose, probahly ''^■^^^ to C'^osion. I'l.e primary concentric rugae are further apart than, on the assoc- iate? P. hrowni n. sp. The Tampa siles form is hardly identical with one from Santo Domingo; being smaller with a less prominent posterior dorsal area, more numero^is concentric rugae, without secondary concentric sculpture except near the umbo, v/ith obsolete radial sculpture and finely crenulated inner margins. Occiirrence.- Up-ier Oligo^ene: Santo Domingo (&abb, 1''73; Dall, 1905); Lower !:iocene : ?Bov/den he's, Bowden, Jamaica (Dall, 1905). - 355 - Sub senilis Here GalDb. Seotion Here s. s. PHACOIDSS (E^-^) .:.^.x.;-;i!TUS Lall. luc ina ' ■'^crjis : Ivsiii oa Gtippy, 1866, Quart. Jonr. Geol. Soc, lon- rlon, y^l. '^2, -p. ""'^P (non I-innaeus, 1758). I'iic!l:na Penns^/lvsniea Guppj'-, 1874, C-eol. I.Iag. , dfcade ?, vol. 1, p. 44S , (check list), ex parte, non linnaeus, 1758. Lug ina r'ennsylvanica Guppy, 1876, '^/jart. Jour. Geol. 3og. Ion- don, vol. '^2, p. 550 (non linnaeus, 1758). Phannjdes (Here ) pocJaFrinus Ball, 1905, Trans. Wagner Free Inst. 3ei., Philadelphia, vol. 3, pt . , o. 1365-1?65, pi. 50, fi'ts. IS, IS. 3e script ion.- "Shell v;hen 2/Oxm.g moderately convex, when senile having an exaggerated thickness and almost spherical con- vexity. It belorigs to the group of P. penns;, Ivani cus I., of which species it is doubtless - precursor, smd the mention of that species by "abb and Guppy in the "Miocene" (=01igocene) of 3t. Domingo and Jamaica doubtless refers to ^lie "oresent fossil. For this reason it is best described by eo!:i,Jux'ic.'jn with ?. -oenn- sylvanicns. from which it differs by its smaller size and great- er inflation at maturity, its finer and closer concentric sciMu- - c\-^o - J± t"re, its :=;'h-r-'r anr"' hr _. -i-n--- '^-r ■'' ->rr.--'l -rf-r^^ its less elevate"^ 'beaks, ito sj ' ' " ,■ Si:3al].er and more dlsoinctlj liniit- efi anterior dorsal area, and its more nearly cin- ;line. It. £8, lOii. , '. ... 'T' rnrn. The lar--"sf: r-r^r^-' 'bserve-'' has a length of 42 anl a diameter of '35 uuu. , Vvliil pecirrien of _?• 0 enns '"Ivani ous of the sarae size has a diameter of onlj? ^5 mm." .\ J cardinal "'.__:.. -^^ -f^he fossil are ■-'"'r- r^^ie'r^ r-.i^ve -^i^-'^r- out than in the recent shell, in which t>:e tv.o a mall ex" cardinal teeth are ns-ually very ohscure or even ohsolete Xla. adult speoi- •ens." (Dall, 190.?) ~:;ve locality.- 30Y;den, Jamaica. Shell of moderate sizu, outline nearly circular; immature v-''.ves strongly ".T.nrrt-- oo-,- •-! .-, shell thiolrenc^, v--.oessively con- vex and suhspherical; omhones of adult shells relatively broad and low, on ;o "" liigh'-r and narmwer; posterior area "broad; \7el1-def inf^'" , :■■.+■ ^---^v rSorsar- - ' ■ ''- "broad; ex- ternal surface sculptured with regular, closely-spaced concen- tric rugae, continuous across the posterior bh ' -r areas and on the largest shells crowded tovrar-'"' -'■ L.tr^.l . argin; hinge strong; inner margin of the valve often "bearing obscure, minut e ere nula t i o ns . j^ema rlrs . - Althou-"!^ -^^-;o specie: ' '- represented "by a lt'-'^~° num"ber of individn.als, there is a rather ' - the ser- ies "between the few excessively convex, largest forms end. the - T^Zl - snail er, less Gonver> speoiraens, uhich also have more prominent umlDones. The lar.p-est oi '" 'ore normal she]"' ..ollow- vcr- di, Clio J.O..D :- I^-oi:., . .; :'1/-., ., ocrnidiam. , 10 vwx, -' c • lallest of fhe inordinately'" conver forms fiirnishes those measurements:- lat., ?E ram., alt., 55. 5 nm., '/ '• .,15 m:'. Dall has fi — - ' -■-- -^"'e -----ptlj^ convex .<),l.:.. . ^^ shells have a decidedly different aspect heoause of their narrower and ■-■fjher ujnhones, as well as because of the no'^^ehle '■" -'c in convexity?. The strong eonvexit- •^-" even ..ij-'-'L'.l J ' '■ "Is the rather fine concentric ri\q;ae are the characteristic fea- trires of this species. The Tampa silex P. v/acissantis Dall (1) (1). loo.,--it., p* 15 65, pi. 50, fig. 15, 1905. is smaller, less convex with a steeper and longer anterior --^or- sal mar -in. The adult P. -leraii Dall [2] from the Ohipola marl, (2). idem, p. 1566, pi. 50, fig. 17. is ^ I'Onvex, with smaller rnhoues and coarst-r nor.np-^tric sculpture. P. densatus Jonrad (r), r.hich occurs in ti:e OaJc (5). Am. Jo'zr. Oonch., vol. 5, p. 15, 1867 ( =L . pennsvlvani ca Tuomey ^: Holm.es, Pleioc. IPos. 3, Gar., p. oC, pi. 18, fi 5, 1856; non Linnaeus). Grove fawaa as well as ' '-"■ e i>uplin, is also less convex, lar,?- er and with lov/er uralDones than the normal 3orden " , a steeper and longer anterior dorsal marg-in and a longer -nosterior area. To statement is made in '[Jahb's Saiito jomingo niemoir concern- ing the I.Iiooene occixrrence of Luoina pe rm e.^' 1 vani o a and there are >i>-cr speci'-^ens in hi?5 col'' ection that mi.^ht have "been referred to that soecies. ^■'^V'P^J » however, listed it from that island and also from Oujnana; if these forms are identical with the Bowden one, -nodagrinus has a v:16.e distrihution. Occurrence.- Upoer Olig-ocene: CJ-aracao (Dall, 1905); Ou- mana f'-Ttro-n;:^ 1874); Santo Domingo (Suppj-, 187"-, 1876); lovrer Miocene: Bov/den he's, Bowden „ Jamaica (Giippy, 1856, 1G74; Dall, 1905). - 359 PKiaOIDSS (EEHE) POMaHIITUS var. AL ^.^ .--o n. var. DescriT)tlon.- Shell reseniTDlirio- the trnir^al normal pofla- g-rinus, "but smaller and less infli::jKa; nuboiieti ' ^ ' '- ; and slig-ht- ly less tiunid; posterior area lono-er and narrower; ; '.or dor- sal area slir'htly wider. .Ji.,.ei.iaio-,s.- lat., 26.5 an;:.; alt., 27.5 r;ii;:. ; . .lidiani. , S mm, Renarlrs .- To P. podagrini"'.s is referred a p:To-cro of s"oeGi- mens that are readil^^ recognizee' since the characters of indi- viduals of the same stage of growth are constant. "The present variety is established for certain forras that are immediately recognizable, although the individual differences that sepa- rate them from podagriniis s. s. are not very pronoimoe"!, ex- cept for the disparity in inflation. The variety resembles more closely the forras discussed under podagrinus than the typical form, since it is smaller and less inflaterl; hn.t the other riifferences pointed oht^^in al-so for the var--'=tr. Occurrence.- Lov/er TCiocene : Bowden beds, Bowden, Jamaica. - 7'%0 - PHAOOiDrs ivzn::.) 3i^ov^i:i n. sp. Oescrj-otion*- Shell of me^lium size, moderately inflaterl, saborbicular, the posterior dorsal margin being long and only slightly curved a: ? posterior lateral marrin obscurely sub- truricateri; anterior florsal margin with a very gentle slope; ma- bones lov/; posterior area v/ide, not deeply imprescpd; anterior dorsal area sharply impressed; external sculpture of prominent, evenly s'^^^'Cti^^ oo".'^ entric mgae over the entire surface of tl^e shell. Dimensions.- lat., 37 mm.; alt,, 35.5 mm.; semidiara. , 9.5 mm. Remarks.- Tv/o valves, one of which is adult, form the ^as- is of this species. It is characterized by its gently curved pos tero-dor sal margin, lov; umbo •^^•"■' ■':'rominer:t , regular concentric? sculpture; these features se^oarate it from po-lagrinus and the forms with which podagrinus is compare^!. Superficially it resembles more closely the recent './est Indian P. pe nnsy 1 vani c us (Linnaeus), (1) (1). Syst. rat., eri. 10, d. 688, 1758; Reeve, Oonch. Icon., vol. 6, lucina, pi. 6, fig. S9, 1850. which ranges back to the Plioceti.:;, uhan the other Bow den forms, but it is less inflated, less orbicular and has a shorter antero- dorsal margin and finer sculpture . 1-here is a possibility that this is the form v/hich Crup-ny designated pemisylvani oum ; the uneommon occurrence, hc-ever, militates againt the supposition. Here, as elsewhere in the r^roper placing- of Guppy's erroneoiTSly determined S;-)ecies, Dall ' s state- ments are followed since he had access to original labels in Guppy's collection. This S'^ecies is named for Dr. Amos ?. Brown, of the Univer- sity of Peniiaylva-ciia, v/ho has made several cont:.'ibutioxio bo the paleontology of tropical Am.erica. Occurrence.- lower 1.1 ioc ene : ''owden bed^i, _^ov;den, Jamaica. - 7A2 ~ PIIAOOIDSS (HUIS) TITHOniS Dall. Phaeoiges (Here) tit^.onis Dall, 1905, Trans. ,7agner Pree Inst. Sci., Philadelphia, vol. 5, pt . 6, p-g, 1566-1567, pi. 50, fig. 10. Sesorigtion.- "Shell small, rotimd, \7ith rather prominent beaks, the rlorsal areas not distinguished hy s culpture and indi- cated onlj^ hy faint, broar!, radial sulci; lunule small and deep, no escutcheon visible; surface with -nrofuse, elevate'\ rather mievenly spaoe:"^, ooicentric lamellae; hinre well '"^ eveloiDer" ; mar- s-ins minutely c-enulate-. Alt. 4.0, Ion. 4.5, di- ,. ~, i nmi." "This little shell, represented only by a single valve, is apparently the precursor of ^. sombrerensis .DpII Cl), a recent species from :intillean waters, which is, ho\"ever, larger, v/ith (1). Bull. I 'us. OomT)t. 3ool. Harvard, vol. 12, p. 264, 1886; Proc. U. S. llat. ITus., vol. 12, it. 255, r,l. 14, fig. 15, 1339. more regi^lar concentric sculptu.re, m.o ~e delicate hiri^p, . near- ly obsolete lunule. A:- -i e radial impression, which v/as at first taken to be pathological, e^rtends on the fossil towards the anterior base. The ■-•■?■ ■■^n-^. -^--rr-Q show faint tr^ce"^- •'■-^ ^ similar sulcation. In them the anterior rlorsal area is not visihle de- limiter! and the creniilation of the r:s.rr-ins is more feeble." (Dall, 1905). '^\y'pe loealiti-.-. Ba7den, Jamaica . Rerrar>:s.- Tv/o valves of this snail form are present. It is at once distinguished from the young of associated species hy its prominent, lamellose consentric sctilptiire. OcQurrenco .- Lower Miocene : Bovrden hec^s, Bowden, Jamaica (Dall, 1903). - 744 - SeotiDn Pleuroluc ina Dall. PMOoiDES (pi;:ui^oiuaii:fl.) quadhioos'^^.: : jjaii. Phaeoides (Pleurol-'aoina) qiiadrl cost atiis Dall, 1905, Trans. Ta.'jner :?ree Inst. Sci., " ' ^ iclelphia, vol. C, pt. u, p. 1368, pi. 50, fig. 7. Descrlr^tlon.- "Shell snail, plump, olDliciue, high, short, with strong Ij-' ir'pressed large dorsal areas; bea'^rs small, -orosogy- rate, overhanging a very snHll cavernous luii' "" _ ; lic^'s.-- p-nt short; surface densely covered T7ith high, concentric larnellc.e slightly wider interspaces, the d.istal edges of the lamellae wider and re f le "- f-^ '"'' 'lorsally; radial sculpture of four rapidly dis- tally widening broad ribs separated by narrow sulci, the two inner ribs wider than the outer pair; hinge normal, strong; scars normal; Inner margins of the valves crenate. Alt. ■', lOi.. 5, diara. 7 ram." "This is doubtless the orecursor of the following species r^. aTiiabilis T)ai:| and of the .^.^ent v. leucooyma Oall." (Dall, 1305). Type looalit;.".- Eov^/den, Jamaica. Remar^.- Two -'^•i ^'•■-c- ^ ri-.-.a. •- either collc^-'-" ■^••\ are the only representatives of this interesting species. It stands imiqiie a'^.ong- the Bov^den lucinoiA forms. P. qiisaricos"! ■lioeene P. aniaTjilis TJall (1) anfl the ^.ecent ./est Indian P. le neo- oyma Dal 1 (r' jinogeneoi;^ group. The Pliocene form is fl^. "^rans . 7a;^Tier "^ree Irist. Sci., -hilar'elphia, vol. .^, —'-. . 4, ol. 25, fiirrs. 9, 9a, 1898; idem, i3t . 6, on. l?on-:i.:^69, 1903. f?1. "nil. !ais. Oorirot. .^ool. Harvard, vol. 12, ^ro. 264-2^5 / l'^R6 ^roe. TJ. S. I^at. Mus., ^^1. 12, p. 26.'5, -ol.'l' , " . S, 7, 1889. Isrc-er than oTiacl-rloo static's r/ith :fi. ner pnri less lamello ture; while on leucoc~-r.B the sulci on defined and the scnl-oture is also less lamellose. Ocourrenee.- Lower Miocene : Bov/den "beds, Jiowden, Janaica (jjLll, 1905). ^ ^^Jkf'" Section Oaviluoina Fischer, PHAGOI^SS (GAVILUGIM) RECURRSITS Dall. Phaooio.es (Oaviluoina) reci-U--rens Dall, 1903, Trans. Wagner iPree Inst. Sci., Phils delphia, vol. S, pt. G, r,. "), -ol. 52, fiC". 11. Phaooides ( Oaviluoina ) reoiirrens Dall, 1915, Bull. U. i3, liat. I'ais., no. 90, o. l'?8, pi. 24, fig'. S. Desoription.- "Shell small, flattish or only ::ioderately convex, ohlique, ine';:i"'i')ater8l, the dorsal areas hardly indicated; hea'-a s;:e,11, lov:, pr'j;='j-- rate over a sniall., moderately impressed rather narrow .1 mi ule; posterior dorsal margin eonvexlj? arched, as high as the "beaks ; sxirface finely, concentrically rather close- ly .Trooved, "i."':h, towards the "base, -^vjo """ ■'-''---- deep, concentric sulci indicating resting stages; hirre-teeth s:te1] hut distinct; inner marn-ins of the valves minutely crenulated. Alt. o.5. Ion. 5,7, d ia.i:u 4.0 mm. " "This little species is more like the re' st Indian P. hlanrius Dall than the intervening cold vrater llioeeiie forms." (Dell, 1903). Type locality.- Bowden, Jamaica. Remarks .- This s 'p-' '^ '--■ p , vhioh ' -^ ^■'•"••f^ vr.-r-- -.> ^ in con- spiciious for its smell size, decidedly inequilateral outline and prominent um"bon:s. The fine Goneentric sciilpture is obsolete or entirely/ absent on most of the specimens at hand, the surface beiiip- smooth except for the often deep, irre"-^"'i'~ '■'I;" ^''■'.sposed siil- (5'i, vhieh may be nresent on any portion of the srirface or alto- gether absent. The Recent P. tris'i] oatiis fOonrad) var. blandns Jail (1) is narrower, v;ith prominent, fine regular ooncentrio sculpture; the (l). In Dall and Simpson, Bull. U. 3. I?ish Gonna., vol. "0, -ot . 1, pp. 493-494, pi. 58, fig. l,'^, 1901. Duplin P. trisulcatus (Oonrad) {?.) and its varieties multisirtia- tus (Oonrad) (5) fDuplin) and whitfieldi Dall (4) (Oak Grove, r.iocene and 'Jaccamaw) are distii:g' i.^iB ;;ad by their uiirrower uxiibones. (2). Trans. Am. Assoc, li'at . and Geol., vol. 1, p. 110, 1841; ?os. Ked. Ter. U. 3., p. 71, nl. 40, fig. 5, 1845 (as Lueivig trisulcatus) . (?). Proc. Acad. lat. 3c i., Philadelphia, vol. 1, p. ?07, 1843; 70S. lie'., Ter. U. 3., p. 71, pi. 40, fi,-. 6, 1845. (4). loc. cit., p. 1370, 1903 ( = ?Lucina tris-'ilcata ..'hitfield. Mon. U. S. Geol. Survey, no. 24, p. G4, pi'. IC , ^"'-3. 1-4, 1895. deeper lunule and coarse concentric sculpture, ^'any of the Tampa silex recurrenn are narrovxer than the average Bow den form, whil( the Ohipolan specircns reach a larger size. OcQurrence.- Upper Oligoc ene : 3ile; "beds, Miami, Florida (Dall, 1905, 1915); Ohipola marl, Florida (i(^ein); lower Mio- cene: "^ovrden beds, 3owden, Jamaica (idem^. - 549 - Sii"bgenus 'Pseudomiltha Fischer. PH-4GOI]3E3 (P3EUJ)0MIIT^--^A) . n. sp- Sesorirition.- Shell large, relatively tliin, suIdo" ', well-inflatecl- ; dorsal margins siihequal, diverging at an angle of about 120°, rounding into ^■"'^•'^ lateral marf^'r'-:' ; i-'i-^n low, flat; external surface sculptured with concentric v/r inkle:; " irregular striae, unequally emphasized and irregularly disposed; hinge eden- tulous; li,p;araent -'V'^v-f:^ ^^r^o--^l-■ inset. Diniensions.- T; '. , i-£.5 r:im. ; alt., 42 mra. ; semidiam., 11 mm. Remark s . - ?. ■^-lijjiiindus is described from several more or less fragmentary valves, on most of which tht _Lii.:.eri-:' ' inacces- sible. That it reaches a larn-e size is indicated by a fragment which, if complete, would have approximately- the following dimen- sions:- lat., "n -n.; alt., "^ --■ . ; -•omidic::;;. , Iv ::;;-. The char- acteristic feat-jres are the thinness and convexity of the shell and the larre size. Toula's Gatuji "Lucina (Lorl^.y-d) f.oec. ' . .^'' -'"' . Torijoes_ edentula limie" (l) is "oerha-os identic?" ■ ' / Jahrb. K.-k. ?eol. -vfiohsanc ::-' "-, "ol. oS, j. 7::u, ol. fig. 3, 1908. higher umbones and shorter anc less steeply sic dorsal mar- - 550- gins. ihe Lliocene P. f ore man 1 (Ooiiracl) (l) acialler, j.ess (1). Jour. Acacl. ilat. Sei., xhllaclelpliia, vol* 8, p. 18-1, 1842; ?os. Ilea, Ter. U. S. , . "1, pi. 40, "■ . 4, 1345 fas Liioiija foreripiii) roimde.d and hecvier and ?. anodonta (Say) (2) is much heavier. (2), Jour. Acad. Nat. Sol., Philauel-ohia, vol. 4, p. 146, -nl. 10, fi£:'. 0, ■13S4, fas Luoina ano^Q-ita). more eom'oressed and less orbicular. Oecurrenoe.- lov/er lliocene : liov/den oeds, Bov/den, Jamaica. - 551 - Subgenus Oalluoi^^a Dall, PnAGOIDJSS (GALLUai::^) PAUPEHATUS ( Guppy ) Luoins -paiiperata Gupp^-, in Guppy and Dall, 189G, Proc. U. o. Hat. ilua., vol. 19? -. _, -1. ^0, -' . Z, ?h a GO ides ( Oalluoiaa) pauperatus ( Guopj ) Dall, 19 OS, Trans. V/agner S'ree Inst. 3si., Philadelphia, vol. 5, pt. 6, p. izao. Description.- "Suh orbicular,, not very convex, with faint, broad radiatiri^ {ray-lilce) grooves and sublainellar concentric ridges. Diameter, 11,5 ran. The radiating ornament looks li^re color, but it is really faint, shallov/ f lutings," (Guppy, 1896) Shell of medinjn size, v/ell inflateiT, suborbicoJ] ar, being slight- ly Ciore produced anteriorly; ant ero-dorsal margin verv short, slightly excav-tea, upper portion of the antero-lateral margin ob- licjuely subtruncated; posteriorly almost' vertically subtruncated; umbones tumid, but lov7; anterior and posterior dorsal areas poor- ly defined; lunule narrow, shallow, of variable length, often- absent or poorly developed on the left valve; external sculpture of fine, often unequally emphasized, closely spaced concentric rugae, becoming sharp and sublamelloEe to?:ard the raargins aiid on adult shells not infrequently obsolete on. the dorsal r;iediaja portion of the shell, in whiel. case the concentric sc^ilpture consists of onl^- irrecrviiarlj- ST'Scecl inorementals ; -.-'> ^ " ^-f-'r,.- from f'^^^ .--^o over the disk numerous verv obscure rat^ial elevations arid wider' depressions of varj'ing width, occasionally entirel;^ absent; hing-e •"*i;> one right and two left vardinals; inner margin of the valve finely ereniilaterl. Dimen.- ioiia.- lat., 16.5 mm.; alt., 16.5 mrn. ; semidiam. , S.n mm.' Remarks.- 'Ihis is one of the most abundant of the lueinidae. The largest individual has the following dimensions: lat., 18.5 mm.; alt., 18 mm.; semidiam., 4.6 mm. The diagnostic feat^jres are the obscure radials, the fine concentric rugae, which become slightly raised and sharp toward the margins, both vent rally and on the dorsal areas, and the c renulatioiis on the inner margin. 'I'he radials are always weak, but occasionally they are sufficiently emphasized to cause the edge of the ventral concentric ru„gae t5 be slightly unrlulated. In addition to these relatively coarse radials, very fine and obscure radial lines may be present on the me'iian portion of adult shells. Yoimg valves which have the radials obsolete and ■■■'^'-' concen- tric sculpture emphasized may be confused with the associate'' i:yrtaea limoniana of the same' size' and this resemblance is aug- rjsnted by the similarity of the "uij.ige. In general the ^jruaent form is slightly more convex, with more prominent nmbones and a - 355 - stronger hinge; these differences are, hov/ever, slip-ht and v/hen thej? fail the crenu^ati'" ' ~ ' " ^:l:e inner margin of paupers viio . which on young valves is xi.sually more prominent than on adults, serve as an infallible criterior for separation. P. radians (Gonracl) (1), v/hich ranges from the Duplin I.Iio- fl). Trans. Amer, Assoc. Eat. and Geol., vol. 1, p. 110, 1840; Tuomey and Holmes Pleioc. Pos. 3. Oar., p. 57, pi. 13, figs. 4, 5, 1857 (as Luc ina radians) . cene to the Recent, is very closely related, hut is in general slightly more convex, not as v/ide nor as compressed toward the margins, with a relatively long, sloping anterior dorsal margin, which rather abruptly joins the lateral ::;argin, a no"r'e ronnded posterior margin, hig>ier narror/er and more strongly gyrate umbones, stronger sculpture and a decidedly heavier hinge. Occurrence.- lower ?:ioGene : Bowden beds, Bowden, Jamaica (Guppy, and Dall, 1896; Dal.l, 1903). - P"54 - PHAOOIDES (GALLUGirA) PATTP^II^ATTJS ' var . OLIGOGOSTAruS n. var. Desoi-jption.- Shell resembling the t^-pical pauperatus. but more ror-nr^ed, Ti.'3'u.all37 more inflated, especially' toward the margins; xjinbones tending to be slightly higher; dorsal areas less well define'; radial sciilptixre weak or obsolete; concentric sculpture coarser, heavier, more regular and ^resent over the entire disk. Sir-, en si Oils.- lat. 17.8 mm.; alt., 16.8 mm.; semidiam. , 4.5 mm, P.emarVs.- This variety is proposed for a number of valves, that are conspiciioxis becap.se of the their prominent concentric sculpture. Variation affects the convexity and the outline, some of the specimens having a longer anterior dorsal margin and a proportionately greater v.'idth than the t;-oe. ..'hen compared with the typical pauper.g.ta. tbese valves form a rather corapa'?t groap, the most obvious difference lying in the coarseness and prominene of the concentric scr.lpture of the variety. P. radians (Gonrad ] (1) is separated by its narrower umbones, longer anterior dorsal raa.r- (1). discussed above. gin and stronger hir^e. Occurrence.-- lower lliocene : 3owden,beds, Bowden, Jamaica. - 25 5 - PKA0OIDS3 (OALLUOirA) SURUGOSTATUS n. sp. Sesorl i-'tion.- 3hell small, decidedly inflated^ suborTDicular ; antero-dorsrl mar grin short, deeplj' excavated; posteriorly culstrun- cated , proluoed and. roiiiided anteriorly; ui./ ' aid, ..arrow, relative- ly hig-b; limnle :.te, deeply inroressed; dorsal areas o'bSGure; external surface scalptnred with rela"^ively rhoad _. ^ j radials and fine, closely and evenly spaced low, concentric lamellae, poor- ly defined in the median dorsal region; left ynlve with two cardi- nal; inner marpln of the valve with obscure fine crennlations and broader tmditlations- the -undulations conforming to the external radials and extending up toward the umbo posteriorly; right valve not laio^Tn, I'i^gnsions.- lat., 8 can.; alt., 7,5 mn. ; semidiam. , 1.8 mm. ?.emar>s . -. This sipecies is represented by one left valve. It is disting-iishe'i? from the i-n-^n-^n- of -oaimeratus and its variety of the same size by the greater conve: ity, deeper lunule and much broader, more oronounced radials. Occurrence.- lower Lliocene: Bowden beds, Bowden, Jamaica. Subgenus Parvilucina Dall. Section Parvllucina s. s. PEAO?ID-:S (PARVILUGirA) YAQUEirSIS ( C-ebl) ) . Lucina Yaouensis C-abb, 187?, Trans. Am. Philos, 3oc., nevj ser., vol. 15, p. 251. Phaooides (Parvi lucina) 3'aquensis (G-abb) Dall, 1903, Trans. 'Jagner Free Inat. Sci. , Philadelphia, vol. 5, pt. 6, p. ir-82. Descriptio" .- "Shell minute, convex, sub-trar.slueent; bea>s central, prominent; hinge line deeply excavated under the beaks, sloping, slightly oonve:-; behind; base and ends regularly rounded; hinge thin, teeth \7ell develope". ; mal mar-in minute- ly crenulated. Surface m.arJred by small concentric lines." (Cabb, 137Z). Type localit;;.- Santo Domingo. "This species differs from thr Chipolan form, P. s-phaeriolus -sll ^1) , in being much more delicate, rather smaller, v;ith fl). loo. cit., p. 1582, -11. rp_, ^i ~. 13, 1905. almost obsolete radial soulptixre, much smaller lunule, and strong- -\ more ro-nded, aiid cloce-set concentric sci\lpture; the largest valve is about four millimeters in Icng'^h." (Dall, 1T:^'3). - r^s? - Shell snail, subequilateral, v.-ell-inflate'^l ; antero-clorsal mar- gin eTcavatecl, postero-iorssl nln-'.oF;"^ stral ', ;lo-nin."-, meeting the lateral niargin at a subrouiide ^ le ; aritcro- lateral margin longer and less ciirvei than the postero- , the base sloping to- ward the rlor end; ur^ho-es relati- [■ ^ '; ; Imiule small, cordate, moderatelj^ iraprcoocd; esoutoheon v^r^- narrov/, scarcely; differentiated; dorsal areas p-^orl^;^ defiiied; e-'; ' -"face sculpt-'u-'ed v;ith nl-: '^ . \ thin connfi:-t-io 1 a-^,- llae and nar- rov;, obsolete radials, separated b;- iiarrov/er intei'spaees; occas- ionally the radials strong en- ';o slightly erenulate the lam- ellae; i"adials absent on th'- ""'ir.^l „roas; hir.re noi-nal, the lat- erals, especially the posterior, elongated; inner margin of the valve finely and wealrly oreniilated. Di ■^'nniO'-'^.- lat., 5 ''■"':'.; ^T""., 1-." .; ^' ^ '■:^ "■''•■ ?.ra. , 1 • " -i': a . - rhis species is fairly I'lrell repr esente'^ . It i: recognized by. its small size, close, "■ ^entric sculpture •rr"' obsolete radials. Occurrence.- U~0T)er Oligocene : Santo Domingo fGabb, 187?; Dall, 190?); Lower I.'ioc e.;-c : '^■'^'"-■'en be(^s, Bor/rlen, Jamaica (Dall, 1903). - 358 - PHAOGIDi.S (PA::7IIU3II:A) 22Q72Ti)U6 n. sp. Desorlptlon.- Shell small, v: ' ely inflaterl, wider than '-ig-h; antero-dorBal marp'in. nl^.'^htl^' er-'cave ' ■ , '7t?ro-''lors'^:l longer, al:nost straight, jainij.. '■" ^joo ueri.'r ^ :io-triu:.cation by a roiu^de"! angle; anteriorly? pro ', ; s low; limtile cordate, moderately ir.rnressed; dorsal areas poorl'- defined; external surface scr.! ' " ith numerous, fi. , : "^ jss olDSolete radials, separatee by slightly narrower i.. aces; the radials absent from the f^orsal areas; entire surface v/ith thin, fine concentric lamellae, sli:~htly crenulated by the ra^lials, often eroded; inner -margin of the valve finely erenxilatc:! . Di-'nensions.- I8t. , 7.0 ram..; p"^'"., '".5 :n. ; JcmAfHam.., 1.3 rm. Remarks.- jj.pical form.s '^ '^ • . ■ ^.re rather ra.re and are characterized by the niimerous weak radials and thin concentric lam.ellae. They are separated from ?. yanu;. by their larger size, less inflated ajid less ro ""^ , more obvious radials, thinner and more vridely spaced concentric lamellae. In addition to the typical valves, from v:hioh the desc i-otion is drav/n, a large iiumber of 'oiizzli' " '"•as are doubtfully referred to this sx)ecies. They "orobably should constitute at least a sepa- rate variety, biit, appearently, they are nestlers, a bewildering arrcy of variation is -rresented. All have in general the same type of sculpture, narro^v, v/eaJc radials and thin concentric lam- - 559 - ellae, both " often 'ber'l; ^ni, >>-'''t tl'' e ovf-l' l.y':- ion is deeldedl;, inc'ons l. .-,■.: li . .jux ji..^,l„ i.uJlL-jt- rj \ small YO.lves of tills group differ from ?. aetinus hy their narrov/or and v;eai-:er radials and thinner lamellae. Oooiirrenoe.- Lower I-Iiocene : Bowden "beds, 3ov/d.en, Jamaioa. ,^60 - PilAOOI.DiS (PA:r7ILU0i'.i. ) LIMKLIi/U3 n. sp. Description.- Shell small, sub orbicular, dcoidedly inflated; more evenl;: rounded anteriorly?; umbo tixmid, high, broad; lunule relatively large and rleeply ir-pressed; dorsal areas poorly defined; external surface sculpture'-'' '"Ith numerous, vzealc, narrow radlals, separated by interspaces of about the same width and crossed by irregularly disposed concentric wrinltles and low lamellae; hinge with a single cardinal and the laterals, the posterior more elon- gated and comoressed; inner margin of the valve weakly crenulated. Dimensions.- lat,, 5.5 mm.; alt., 5.5 mm.; semidiara. , 2 mm, ?.erna r]: s . - This species is described from a single valve. The siiBll convex forms discussed imdcr the preceeding species are intermediate between -oroteidus and linneidTis; from these varieties limneidus differs by its greater convexity, more tumid and high- umbo, slightly coarser sculpture, larger and deeper lunule. 0 ccurrence.- Lower Kiocene: Bowden beds, Bowden, Jamaica. - 561 - Section. Bellucina Dsll* PI-IA00IK;S tBEILUOi:.A) AOTinUS Dall. Phacoicles (Bellucina) actinus Dall, 1903, i'raus. V/agner Free liist. 3ei., Philadelphia, vol. 3, pt. o, p. 1385, pi. 52, fi^^. 3. Dc script ion.- "Shell small, pluiap, somewliat inequilateral, with moderately prominent, slightly decurved. he airs; smterior end larger and more inflated; lijnule lanoeolate, somev/hat longer and narrower iii the right valve, distinctly impressed; esciitcheon impressed., almost lin^pr; disk VTith sixteen to cx^'^ctne-p roi^nded radial ribs, entire and wider towards the hase, v.lth narrower deep interspaces; co2icentrio sculpture of thin lamellae, v/ith much wider interspaces, w'-^'ch are sopiewhat crenulate'^ or wave'5 by over- ridi.iig the ribs and nipping into the radial interspaces; riorsal areas large, sli?-htly impressed, with no radial sculntiire, the concentric lam.ellae on ti-o nri,q-*:.=>rior area close-set, low, hnt on the bounding rib and on a radial line near " " -aal margin slightly elevated; hinge normal, delicate, internal margins minute- ly crenulate. Alt. 4.5, " . "^.i", .-'am. -"^.O mm." "This little shell is near the typical Parvilx7.cina, but be- gins to show the Bellucina characteristics i. its sculpt -.ire. - 762 - which in Si-^eoies of later horizons we fiwi -FijUv nevelO'^p''-'' . 'The chief variations are in o^itline, sons being roimder or higher and shorter than other spe cimens." (jjhll, 1905). Ty-oe locality-.- 3ov;clen, Jamaica. Reimrks.- Ths small valves of this spe- ' j.re very abuiid- cnt. The nrunoer of radial ribs maj? be as high as twenty- two; the escutcheon is not as deeply impresccd as the Ixmule and the poster- ior dorsal area is more conspicxTOus than the anterior. The degree of inflation is subject to decidea variation. Either the radial or eonoentric sculpture, or "ooth, may be weak. Valves with sup- pressed radials closely approach P. yaguensis. froi.. which they may in general be distingixished by their coarser concentric scuJp- tvve , more pronomicec! -:)osterior dorsal area, more deeply impress- ed lunula, slightly heavier hinge and deeper and coarser inter;aal crenulations ; the typical actinus is, of course, readily distinguish, ed beoaxise of its more prominent radials. ?. actinus is soBller, more rounded and more inflated than P. proteidus, besides having coarser sculpture. 0 0 G u rr e n ce . - 1' o '•'•' Q ^ Iliocene: Sowden beds, Bowden, Jamaica. (Dall, 1905). i -. r; *, rz _ PHA00ID..O ( .i_.a.x-uji..A) ABGHOIrx'^..L'o n. sp. Pescrlptl on.- Shell small, sub orbicular, Tno^erately iiiflat- e "^ ; : ' --dorsal niarf-in short, slightly excavated; slightly more prorli^ced anteriorly; tmibones relatively low; lunule small, mocier- atelj' in-presse'' ; ri.orsal areas iiff e rent i ate r1 hy the absence of radial sculpture but rhe pos'; ' ; area obscurely raised, only a radial line near the margin; radial sculpture coiisi sting of about e"- . . radial ribs, poorly 'defined on the I'ledia.. -'tion of the shell and near the niargins, separated by narrower, relative- ly shallow interspaces; concentric sculpture of prominent, regul- arly spaced ribs separated by interspaces of the sane width, fail- ing to override the radials on the most convex portion of the disk; hiixge heavy; inte: ' :f the valve obscurely undulatec! near the rip->"^-" -'-. « in conformity with the e:.ternal radials; injaer ■'•-^-tral m?rgin finely crenulated. Dimensions.- Lat. , 7 ram.; alt., 7 nm. ; semidiam., 2.5 mm.' Remarks.- T>it^ characteristically sc^il-otured "3ell'ioina is represented by a single valve. Because of its larger size and more typical sculpture it is sharply (differentiated from ?. actin ■! On the c-^-'-^v hand, the sculpture is not as -■"^^<'< -■^^'^velo-pe'^ -9 on the Duplin P. tuomeyi Dall (1) and its ■.Vaccamavv and 3aloosahatchie (1). Trans. V/agner Tree Inst. 3ci., Philadelphia, •'"^^ . '" , 6, pp. 1305-1386, pi. 52, fig. 1, 1903. - 564 - variety/ waGcama7.''ensis D?!ll (l) and ^-^ '-- Pleistoc-pi' '^-i :pce-''t ^. (1). idem, p* 1586, pi. 52, fig.- 2. aniientiis Dall (2), all of v/liich are closelj" related. ("). Proc. U. S. Hat. Hus., vol. 25, -o. 826, rii. 39, fir-. 10, 1901. QgQurrenoe.-T.owfir IIIol : 3o¥/den beds, 3ov;den, Jaraaica, GerLi.'ib ^x V _v. . ;..^JILA von Ivlartena. DIVAHIGELIA PlSYAPiIOAM "u-op.?. ?Luoina dent at a '■^abb, 1873, Trans. Am. Philos. Soc, nevr sor., vol. 13,^ p. 251 (non "./ood 1815) e:-: parte. Divarioella -orevaricata QuTJp.y. in Guppy and Dall, 1896, Proo. U. 3. ITat. rais., vol. 19, p. 727, pi. 1^0, fi^. 1-. ■Pi varicella ^orevarloata Gn^^py, Dall, 1905, Trans. .7ag.xer ITree Inst. Sci., Philadelphia, vol, 5, pt. 6, p. 1339. Sesoription.- "Suborhi cellar, inflated, niarcrins minutely dentiotilate, snrf, ^e divaricately seulptiire ''. Length of shell, 8 rira." ^'ype locality.- Jamaica. Shell of medium size, thin, sixlDorbioalar, well inflated; posterior dorssl '^v^i-n ~11 c-T-itl-- longer and st'-'pifrT^ter than the anterior; more eonvexly rounded anteriorly; luabones tumid, relative- ly prominent; lunule small, feebly impressed, almost or entirely confine'' -o -^.he ri'"h"f: v. ~. , : ; the characteristic pnr.-il ti^.-.tp rcaltive- ly fine; incremental lines irregularly spaces and uiieui'.&lly : phasized; hinge strong, the rirht posterior cardino.l sometimes obscurely bifid; both posterior and anterior laterals relatively '.veil developed; inner dorsal margin feebly serrate- by ^' ^ - ture, the remainder of the r.argin non-serrate'', but finely crenu- - y Ob - lated on its iruier e '^ ; . Dlmensloris.- ' -., 1- . :" ;.i .; „1^-, "".1 .; . nniTipr-i. ^ 5.9 rani, Remark s.- Tliis species is a "bunclant ly represented and the characters are very constant esoe'ot that one or . ..„ \- "'.'.- viduals :, ave slightly coarser sculpture than the typical rorm, ■The rather small size, convexity and relatively fine sc ^ "e are -•'••^ ^^- aracteristic features. In outline and convexity pre- varioa'"a closely resemhles the co-e>:istent guadri sulcata, hut it never attains tlie size of that species and inc^ivifluals of the same si^:-^ •'■ --^■^ '"^ * '■-'tinguishe "" by the coar^^-^"'^ "--ciilptu •■"'^: - " - ,iad- ri .sulcata; in audition, pua'o.risulcata has a smaller, l>u' deeply impressed lunule, slightly stronger cer-linal tee V coniev,-''--- '• ' er laterals. The you: g of hoth speci j'", '-o'-'- ever, to be variable in the strength of the 1' ' in the Gi5;e .'-oth of the lunule. Dall has described a Ooi t- chie species, _. ■^■-.j. .osa ^j\ ■■'-ich is also very '^■'■^=- jev^ri- (1). loc. cit., 0. l-^-^l, pi. 51, fig. 5, 190?. cata. but has slightly finer scu'^. ^ture. Gabb's Santo DominP'ian T'l^oina rJensQta inolucie no. that perhaps should be referred co •,:reva- i.a: -v, . -.i.ie others seem '67 - more closely rel'^tetl to '''uadri '•r^l-^ata. Ocourrenoe.- Upper Oligooene : TSanto Dornin'-^o ':'b, l'''-7"1 lower Miocene : "^■■->~'^_en iD'ens, ^o^'e-, ^ ( _, ^:_ ;: ^all, 1896; Dall, 19C5;. » - 5 68 _ ..X .^LLA QUADPJSIILOATA ( - 'Orbigny ) . ■t'ellina "livarloafca Dillw;vn, 1817, vat. '^ec. Shells, vol. 1, . "I -'^ ( ex parte ) . I-ucir-ia ajy&ricata Lamarok, 1819, Anlm. F;a-i-s Yert., vol. 5, .'o. 541 ( ex parte ) . a>-^ "J!*^ . : '-i. : ^i .- :;: -a^a Say. 18?J-, :^our. xlca'^ . "^■^-. 3ci. , "'^^ i --•:lphia, vol. ', '. 148 (non Linnaeus, 17'53), lucina t^.ivaricata Oonrad., 1840, Fos. lie-. Ter. 'U. S., p. P.9, T. ::G, fig;. "^ ^•'-'^r' '^■•i^-j^^o'^F , 1758). Lnc i na d 1 v ar i e a t a laniarok, (iould, 1841, Invert, ilass., p. 70, ( non linnaeus , 1758 ) , Luoiria ouadrisiil oata ^VOr-oigny, 1845 (?), in Ic la , 1st. fis . , polit. y natur. de la Isla '""e DiilDa, I'olluscos, p. 329, pi. S7, fip-s. 34-,^6. (Spanish ed. ). LuQJna ci-uaflrisiilGata -^ 'Orhi.Pii^' , 1346, To;-, :^... I'.ie l . , ..lollusca, p. 584. luc ina -"'Ivari^ata lamarc". , r^A, 1846, Am. Jour. Sei., (H), vol 1, ^j. 1-04, (iion Liiiiiuy iLfc;, ]7--'-^^ Irtclna stri-yjlla Sticipson, 1851, 3'nells of Ilew I^ng., . 17. ' UP ina lonradi c! 'OrhiP-n;;, l')3r, Profl. Pal., vol. , . ^l", pi. "1, fl^. 94. Iiici.^a amerioana 3, B. Adams, 185S, ' . ., . ' '". ITot I. americana Ticfr . 18? 3. L-:TGliia. caiadri sulcata cl 'Or'oir-ny, 135^, i-i oe :.a oagra, Fist, ph^^s. polit. et natur. cle I'lle cle Cuba, ITolli^snues, vol. ", p. 294, pi. ?,7 , fi'B. - .^rench e^..), LxiQ i na 'livarir;ata i-amarck, Juoae-" aiid Holmes, IQoo, i'leioc. South Gar., p. 59, pi. 17, li.re. 10, 11 'non LinnaGUS, 1758). Luciiia rJivarioata Lariiarc:-:, .iolvAez , 1358, L'o&-c-::'le"ioc . -^os. couth Jar., p. r7, pi. 6, fig. 1 fnon Linnaeus, 1758). Luoina lonradii a 'Orhit^nj-, Gonrad, 136?, '^roc. A-^r-^. ITat. 3ei., Phi 1 acl el ph i a , vol . 14 , p . 571. Lugjna ( G;yolas ) Gonrafli d'Orbigny, Lleek, 1854, Ilioc. Oheok List., Smith. Misc. Joll., no. 18r^, -i. 8. J^'^las clentata Yerrill. 1373, Invert. Aniiaalc 7incyard 3ov ", 686, pi. 29, fig. ?^11 (non 7/ooa, 1815). ?L^-ioina den tat a Ga.bb, 187P, Trans. Am. Philos. Soc, nev; r.^r.^ vol. 15, p. R51 (laon V.'ood, 1815) e:: mrte. -i^ivarisell?. quadri sulcata (d'Orbign^, ; Ball, 190.:?, Trans. V/agner Pree Inst. 3ci., Phila^^elphia, vol- ?, pt. 6, ^. i-'^""~t, pi. 41, fig. 1. Pivaricella guadrisul'^ata (d'Orbigny) , Glenn, 1904, I'arjrland Geol. Surv., Llioc. vol., p. •'^41, pi. O-^; --■ . LuGina ( Jivarioella) otiadri sulcata d'Orbirny, 235 Sc, l-^-J., -^1. Inst. Geol. ~ :j:-n.co, p. 77, pi. 11, fi~s. 2, ?. r^.70 - -L'esoription.- "Luoina testa orbiculari, com'oressa, alba, corjcentrice sulDplicata, bifariam oblique striata, inaequilatera; latere anali brevi, rotuncTato; latere bunoali subangiulato, radi- atim 4-siacato; valvula sinistra, Iruaula laevigata, exeavata; intus labro tenuissi'-ae dentiGiilato." f d 'Orbigny, 185S. Shell resewbling D. prevarioata but heav' ■-^v -i^nd larger; sculpture coarser; lunule see. Her and deeper; on adult shells tlie cardiiml teeth slightly stronger, but the laterals showing a tendency t^ o p y- . g^-c >> . righ'^ -,■,.-> Q-!:o-::-i or cardinal more obviously and more usually bifid. Ji-ensions.- Lat., 14.2 nmi. ; alt., 15.8 ram.; seraidiapi., 4.7 mm. ?.emar>s.- Several valves, which cejanot be rl is t ingui she d from the Miocene and Recent rep:- 'atives, are referred to this species. Only one is mature; it is larger than any of the associat- ed prevarioata. The ciifferences betv/een these t- o species are discussed iijider prevarioata. D. chipolana L'all (l), a member of il). loG. Git., 1903, p. 1389, pi. 51, fig. 2, 1903. Ohipola, Oak Grove and 'Jaloo-c.-c, icuL.. faiuias, reaches a larger size than the fossil forms of guadris::lcata, is typically less inflat- ed, 7;ith more equal and eqxially sloping dorsal nsrgins, occasion- 7-71 - ally olDSCuxe radial impressions on the anterior slope, and the right anterior lateral stroi\v-er. It should he noted that the angle between the posterior dorsal margin and the lateral margin on the single adxilt valve a' hand is more rounded than on most cuad- ri sulcata ; t^'pica^ly ouadris'^iloata has thf-> nor sal angles suhaagii- lar, while on chi'oolana the;y" are rounded, hut these features are not constant. Oocurrenee «- Lower Miocene : 7o'-':l:n beds. Bow den, Janaica. Ivliocene: Oalvert forrmtion, Virginia (auotores), ?Maryland (Dall, 1905; Glenn, 1904): St. Hary's '^o-'^o :- ion, Virginia (Gardner, Mss.), north Carolina (Gardner, Kss.); Yorktown formation, Virginia (auotores), "orth Carolina (Gardner, IIss. ) ; Duplin formation Z'orth Carolina (auctoros ), 3o^^th Carolina (Gardner, Mss.); Choctawhatchie marl, Florida (Dall, 1905). Pliocene: V/acca- maw formation, Forth Carolina (Gardner,. IIss.), South Carolina, (Gardner, IIss.); Santa I'aria, Tatetla, Vera Cruz, I'erico (Bose, 1906). Pleistocene: Simmons bluff. South Carolina (Dall, 1905). I^ecent: llahant. Has sac hus setts southward through the V/est Indies to o5n':a Caterina, Brazil in both she^ l^^- ^r' ^ "eep water. - 5 7S - Familj" Diplodontidae. Geniis DIPLODC" ... -'ovm. Section Diplodonta s. a. LiP- -1 .;AIII n* sp. Description.- Shell srsall, stib orbicular^ decide'lly inflat- ed; slightli" more ooriver-.'ly rouiided. anteriorly; imibones tnmiS, broad, eonspicuoiis, subcent ral ; external surface smooth or v.'ith irregiilarly dispersed^ obscure, concentric striations; the loft anterior cardinal strong, bifid, the posterior lamellar, s "or'ar- ginal; rifht cardinals subeqiial, moderately heavy, the posterior obs cnr el y b i f i d . Siiviensions.- lat,, C.5 ram.; alt., ".5 ram.; semidiam. , 2.5 mr r?emarks.- D. \'.-all i , T?/hich is describerT from two valves, has been referred to fl) as D. ca'onloides (f'abb) (2), a Santo -^ominp-ian (1). Dall, '7, H., Irans. \7agner Free Inst. Scl., "Philadelphia, vol. ', pt. 5, p« 1182, 1900 (pt. 6, p. 1587, ^ ^ •^3 (check list) LS ^. oanuioidrs 7n"-T'-^ rr ■ 1 at (r). Trans. Am. Philos. Joc . , ■ ■ r., vol. 15, -o. 252 (as Ky s i a ■? arii^l o i d e s 1 . form, which is, ha"? ever, not a Diplodont a, brct most liTrely a Joonerella. The Bowden form is disting^^ishe d from the coexistent r;iembers of the ^ervxB "b;? its rnarkcd inflation an" \, high urabones. Ihe name iti ^:ivt'u lu honor of : -. . . ..all, ql\q of the merahers of the early Janiaican oitrvej' and also a contrihutor to the liter- ature of the geolop'j- of other 7e£3t Incliaji areas. 0 G G ur re n gc . - I, py? e r Miocene: 3o?;den heds, Bov.'den, Jamaica (Call, 19C0). DIPL0D0:,JA ' L-1 xA n . s -0 . Descrl-ption.- Shell small, r ■ o ,-; r. -^ =-!- p i in flat eel, sli.i^htly more produced and more eorwexlj? rounded antex-iorly ; umbonee rela- tivelv low and inconspicuous; external surface soiilpttired v/ith fine, close-tiot, ^-e'lilpf^ '--ori-entric striations; in'-°-^;'-^l cTmraoters nor- mal • Dimensions .- lat., 6,2 nm. ; alt., C.S mm.; semidiara. , 1.5 mm. Her;ar>s.- In the '"^i? cession '^ f '^' >-■ '^'^- "^-"a '^i-olodontas Dall (l) (1). Trans. '.Tagner ^'ree Inst. Sci., Philadel-ohia, vol. .-, -ot. 5, pp. 1182-11G5, 1900; pt. 6, p. 1507, '1903 (check listU has called this '^'-^^'^ies, -r-m- n>, Tc-represer. ' ^collections at hand "bj" two valves, D, suhc tl ad rat a ( Gab o ) '£)- rename-' gahoi ). -.rarjs . Am, PV.ilos . 3og., (as ITj'Bia suocniadrata) . ■2, 187 ^^ by Dall i'^) tiiiice siVbciiiadrata "'at' In 18o5 ('!) f:^). loe. eit., p. 118 "■, fo'^t-note. (4), Proo. 2ool. SoG . London, p.. 230, 1855. 575 In the '^anto Domingian collection at Phil ^rl el •■','-. la thf^-^e are two Iiiplooloxit as under the name Gn"bq,n£cirata. " " t'-ct Gahh 1^ dec crib ed as sub quad rata is ■ '_ o honialosi.rl- ata, , ': .. .^ , ._ _ ■_ conve^jly rounded anteriorly, v.'ith lower uin' Ithout definite, re~u.lar concei trie stf'T ^tiO:_;^ . T'he 3o?/den ''"ipoL .: c^'o^'m*'^. e'"'' "^'j i'^'? ftiio>,-n •^- inecxiilater- al, moderately convex outline and re^ulis^r oonjentric sculpture. A very closely r elate "'' form, apparently more ro than Toula's ''Diplodon''" 1 ;."' (l) ocenrs in the Cat--^ 'vo-c. . T^ reaches a la^'ger fl). Jahrh. K.-k. ,creol. Reichsaa-js tal t, vol. " , .. "1? -^" '^^ fi-. 19, 1005. » oize; tends to he slig'htly -sr" , , . ;.■"? ---^■'e ".hones. Gccurren''e.- Lower I.iioc ene : Bowdc _ . '_ , -^..., Jar:;aica (Da] 1, 13C0). - 576 - Section _'elaniella D.ll, JDIPIODOr, ^'A V ^..o^iu.i^^jjA) LIII»;Oit us.ll, Dlt)lor^oi-ta f,?ol 811 i ell a) minor Doll ^ 1000, riv/.s. Wagner ^ree Inst. ;ici., fhiladelphia, vol. S, • ", P- 1133, pi. 44, fig. 17, Desert -pt ion.- "Shell sn^aT T , Tno''''er,-^'^e"'7 conyo-:, smooth, polisher", oblique, inequilateral, the lov/er anterior side loro- diiced, the posterior side shorter, rounded; niarginc simple, palli- al line and addnotor sosr.q r:o-r"i.ql, tv.-> ri-.-v, -f: ant erior cardinal suh- Eiarginal, rather long; the poattrior oaraixial short, vertical, deep- I37 "Bifid, the Tae aks low and pointed, hoth the left anterior cardi- nals short, the anterior "bifid. Alt., 4.3, lat. Z.8, diam. S.5 T'sm . " "This is verj- similar to the 01ai"bornian !)_. nana and to the young of the lvle'-"^iterranean _^. _ " :slls Philippi." (Dall, 19C0). Heiig.rks.- Tlie collectiorjs at hand, have furnished a nuinher of valves of this species. It is distinguished - associat- ed nerahers of the genus "by "''""' -t -^ -> ^ - ^^ --t anterior obliquity ':■-- ^'"''^':: moderate inflation. The surface may shovi very feebly concentric striations. The Claiborne species nentioneci above, D, nana lea(l), (]). Oontr. Geol., p. 55, pi. 1, fi~. 26, 183?. - 711 - has definite coneeiitrio striae. Oc currenc e « - laver Miocene: Bov;den tieds, Bor-'den, Jamaica (Ball, 1900). - 7^78 - SectiOi- PhlvQ^iderna Dall. DIPIOHOL^A (PHLYOTIDSrti.'A) PlThGTUr^IIA Dall. Dj-'pl 0 d. OTu. a -Qimo tnrella. Jail . 1809, Jour. Ooncli., vol. 9, no. 8, -p. 245-246. Diplodonta (Phl^'ctideriiB / pimoturella Jail, 1..'^,^, .. ux-o. vVagner Free Inst. 3ci., Philadelphia, vol. ^, '^t . 5, p. 110.'^, pl. 45, fi ^. 26. Diplodonta (Phlryctideriria) puiic tiirej la Dall, Dall and Simpson, 1901, Ball. U. 3. ?ish Ooinm. , vol. 20, pt. 1, p. 495. ICot Diplodonta (PhlyGticler"ia) piinetnrella Dall, 1915, Bull. U. C), Kat. ivi'is,, no. 90, p. 140. Descriptinn.- "Shell small, tl'iin, rouride"-, moderately con- vex, v:ith inconspicuous healcs, outline nearly circular, the bealis smooth, but the Test of the external surface closely minutely punctate all over, other characters as in t^.-oioal Dinlodonta, like D. ca.uuloides. but less turgid. Alt. 6.7, lat. G.5, cliam. 4 mm. " "The minctation 0"f the Rin-fa'^e is ,. ''].o?"e anri ree";lar. not pustulose, lilre most of the L^'xciee " ''liG section," (Dall, 1900). Type locality.- Bov.'den, Janiaioa, Iveaiarks.- Olie two valves tlia t are the onlj, representatives - 579 - of this species differ deoide'ly in conve3:itj', the one, a. left valve, TDeii-:ig 1.9 ran), in diameter, and the other, a rirrht, 1.2 mm. The shell is higher than v/ide, s''.i£htl^ ..lore produced anter- iorly-, translucent, v/ith ohscure concentric lines toward the mar- £-in and- the left anterior cardinal lar^e anr! '-nar'k:e''i-l:; oifid. _u. 0 m^tiirella ib r^eogxiized hy itt :.xK;.til . ./.iell, nearly circiilar outline and minutely punctate surface. It also occurs in the recent Vest Indian f°.vv.a» The Tampa silex form is larger, m.ore orbicular with coarser ]_)LLac tation and oiooahly sho^-T' he considered distinct. Among Gahb's Santo Domingian D, suhquad- rata (l) is a Phlj-ctidernH that is very close to, if not identical with, puncturella, although it is smaller and less inflated. Occurrence .- lov/er I^iocene : Bow den beds, Bovvden, Jamaica fDall, 1900, 1915). Recent: Jamaica, Porto laca and St* Thomas fiJcll, 1915). - 580 - Superfamily L E P T 0 N A 0 ,., .^ . Family leptonidae. Gemis ?:HyOirA lanBrcfe. SulDis-eiiiis .^rj; cilia s. s. ERYCILii v.oAJD?Ji.TA ( GablD ) . I7eaerom:'a niiadrata Ga'^'b , 1875, Trans. Ai:i. Philos. Soc . , new ser., vol. 15, p. 247. ITeaerom.ya qu.adrata Ga^olj, 187?;, Proe. Acad. Nat. 3ei., Philadel- phia, for 1872, p. 274, pi. 10, fxP'S. 4, 4a-'b. Description.- "Shell small, roimded, sixb- quadrat e ; bealics posterior; aiiterior end ^^.T'oduce''"'. , rou,"de''' , ar.ri RTio-iTtly narrow- ed; posterior end hroad^ly romided; hs.se nearly/ straight. 3vx- face polished, narlred onlj hy minute lines of gr:OT;th. Length .3 inch, height .25 inch." (Gab^T, 187".) "..... hiaee V7ith a prominent tooth in the right valve, articulating behind a smaller similar one in the left valve. An anterior and posterior la,teral ■f'^^o^''''' ^'r' p^rl,-'^\ v^ive." (From diagnosis of ITeaerom;:a ) Oahh, 1873. lype lo oalit^'. - .J ant o nomin go . Shell small, thin, elong'ated, subquadrate, decidedly inequi- lateral, being much produced anteriorly; the lorig antero-dorsal - 581 - marf in anf? '''^r'-' -^'o^tral "lar .. ^ abparallel th r ■^ -■•'-■'■-,' ■-^■-■'t ..^x lengtTi, the ventra.l margin vev^ f ee^bly insinuated ;riecTially "by a slight compression of the sl^ell near the marn-in; abrixptly roiUided posteriorlj-, more eonvezli" roiiiidel anteriorl;^; ^•"•^'bones low, plaee^^ near the posterior end; external siirface 'vith fine, inconspionous inorementals; the "cardinal" of the left valve place utTore the urnbo, curved parallel to the mar ' ; ;he lat- eral laminae strong, the posterior long; chonriropl. c . Dimensions.- Length, S.5 nra. ; a" ' . , 1.8 mm.; semidiara. , .8 mm. Remarks.- This species, the tj^pe of Gahh's genus Feaero- m:;a , is, as "Hall (1) has pointed oixt, a typical "'rj^ci c. .."'_; fl). Trans. Wagner ITree Inst, Sci . , PhiladeVohia, vol* r-5, -ot . 5, p. 1145, 1900. collections at hand have furnished two small left valves, snBller than the t;,"pe. I'hei^ are recognized hj' their luiu.. L^aiij elongated outline and virtually parallel dorsal snd ventral margins. Hall (2) has already noted the occiu-rence of this form in the Borden i2). Idem. faixna. Ocourrenoe .- Upper Olinooene: Santo -DoraiiJgo (Gabb, 13"3) ; Lov;er Kiocene : BoT/den beds, en, Janiaioa (Ball, 1900). 3RyOIiIA PlI^A n. sp. Desoriptlon.- oliell of ne di-D.m oL^.u, uhin, o ibtrexislucent, elongate, ^1 inflated, ineqxiilateral ; more oroduce" lore convpxlj' ronndecl anteriorly; a::tero-dorsa3. 'n strs i'-'-ht , slop- iij- t.'xi '..l^ , .L'ot!.nding broadly into the carve c 'ior c "• postero-dorsal raarprin shorter, conve:?:, curving f!ore j into the roimded posterior evA; hase straipht; nmho 1 ' , _, 'laoe^ he- '!~in'^, the meditai ]ix>± i-j- :>l^ al; lue icm v eiv. xc-.l ;jur l ^ e s:iliell very slightly constricted; sitrfaoe hearing vr concentric s striae; rieht valve vath a sinf^le cardinal and :. ';al lam- inae. Dir:ensions.- length, 8 mm.; alt., " .; adiam., 1.5 rara. ?ien)ar":b.- A single rip-ht valve of this e^xeies h.?s j-o^^eare""'. in the collections. It is readily disb- ' j':- _. ';. '\c.'1l^ ;:, hy its much larger size and less ineqfeilateral outliiie. The riocexie (Duplint and Pliocene f '.Vaccarna'.? and Caloos: ' _. carolinonsis Jail (1) is larger, less elongated and less irjflaL"ed. (l^. Tra-ns . 7/'agner "^ree Inst ^ Sci., ■^hiladel->-)hia, vol. ^^ , •'-'t. 5, ^. 111-5, pi. 44, a?s. 5, £2, lOCO, Oec'irrenoe.- Iov;er Miocene : Bowden beds, "^o^vden, J'arnaica, Faniil;- Sportel lidce. Genius xU:i30D0I"rA Des' Seotion Basterotic Al'^ISODOilTA (3AST:.R0riA) BC . ... Jail. Aiiiso<"!onta (Basterotia) bo'.'.'cleniana Ball, 1^"0, . ..agner Inst. 3ci., Philailelphia, vo" . , : . ", -z. 11??. Desoription.- "A species of Basterotia. ^-■-^pears to "be clearly inct from B. otiarlrata "inds (1), -presented b^ (1), Proo. Zool. ooc. London, p. , lo":5 (as GorTpnla ciiadrata) ; Reeve, Oonoh. Icon., Oorbiila. ". ", - ■. '; , "•"■". a "broken rip-ht valve in the collection made "b" ' ' .■ son at Bo'vvden. Hardl;;- conrolete enourli to '" s, it raa;; "be des- cribe' as disting-aished f r -::: ^. gnadrata by the following charac- tftT.?. The keel, ...-^h is "o -^ronirr; 3 in B. . '•? . in the present shelJ- is well niax-ked onlj" on tho beal', rapidly. becoming obsolete distally and represented only bj" a roimded ::i _, .:.!,;„ passes iMwP-pp-.-^i'oi - ■'^■n^-,■^ ' ■] -n-'ivezit^' of 'he valve. 2he beaks in _2« oov- '^eiiU.na ' angular aj"id ele- vated, the shell thlnnc- more ovate, the hin-^e-line longer, t'iie elevated tooth smaller in proportion to ^^' - "'ell cuitl Lu^ch more delicate. The soiilpture is p.iinutely safj-ririate, tlie lerifth 10. ^, ^-he diev-pt.-r s.^oovt "■ '^-i ■-." (i^n1l, ^^ j). ■J^'Pe loocJ-i'::.- 3ov./deri, lea. Shell small, thin, subtranslucent , moderatel^r inflated, transvc-"''"'='T- eloii^?'^'^'"i ^ '-•r-i^f.p-^ ' " " , ; - •^o:.v-,_.t-vc-3-i , o p_ gin short', slino3t straight, roimdirjg oroadl^- into the lorig ob- licuel; siihtruncated postero-lateral inar^-in, vhich ahniptlj roiondG into the base; -■---e attenuated ^ -^o^\-r.^'e^^- -^-"teriorl^, b--.ss gentl;/ arcuate, deccending to\7ard the posterior end; -ambo low, place" -:rd the anterior end, at the sar-e elc/ation as the highest -"--^ -^^ ';;.•,- ^-u-- o .r'^ -^"^ Tiargir. , ■■ng from the imbo to the postero-ventral angle as a rounded keel, flattened toward the margin; near the margins the surface of the shell ^vith relative- ly; coarse grannlationo ; hj '" subumbor. " ""^inal". Dir.'.ensioris.- Length, 5 mm.; e."!"'"., " nm. ; semidiam. , 1.5 mn\. Remarks.-- This species is re^iresented b;; an incomplete, small left valve, ■.'t'hen compared . Li-i- ''"■ — this valve shprs certain differences that probably are due to immaturity j it is m.ore definitely kelled, v/ith a louver umbo, ;ore obviously and coarsely graniilose surface. Other features that are iiot in common are due to the differences betv:een right and left valves; the edge of the postero-dorsal mar~in of the right valve is flexed to- v/ard the interior of the ahell, v.hile on the left valve it flar-L- outvrard and the left tooth is directed more to the rear. OoGui-renoe.- Lower Miocene: Bow den beds. Bow den, Jamaica (Dall, 1900). _ 587 - Family- lielliellidae ? Genus MOKTAGUTA Turton ? .... --iGUTA ? IU^i:0TIJ3T.. ... -p. DeseriptloK.- Shell small, weakly inflated, elongate s;ib- quadre-^e, 'Tp^i'Tpm- Inequi: ._.,.. _al ; roiu'.de;'' ?■■'- --^riorl;,', almost vertically," subtruiicated posteriori^' ; iDase sliR'htly arouate, des- cen'^ing tov/ard the anterior end; antero-dorsal niar.p-in short, sli?.-htly conv°- , -'ith a steep slope, roundin£ ^ v... ,.:_^ into the pos- terior sub truncation; umho low, placed at ahout the posterior third of the length; external stxrface sculptured V7ith strong-, fine concentric '-■'--•ie.^ '^-^ varyir"^ '^■"" " -■^- , -h-^' '^•^'^e occasionall;' slightly lamellose; left valre with a suhunihonal posteriorly dir- ected resiliary s^llc^^s and an ohsciire lamina on either side, the anterior lamina more conspicuous. Dimensions.- length, 5.2 mm.; z'^:': . , ."5.5 mm.; semidiam., 1 mm. Remarks .- -his species is known from a sin^-le left valve. It apparently heloiigs in the same "■^^^■■-- • "/-h v.'ont acuta ? actino- phor£> Ball (1), of the Oak Grove faima, since the hinge of the left (ll. Trans. V/agner ?ree Inst. Sci., Philadelphia , vol. S, p. 1172, pi. 4:4, fig. 2, 1900. valve consists merely of ohscxire anterior and posterior cardinal lam- f'.B inae. The Oak: Grove forn is larger, higher less ineoiiilateral, \7ith '.vealrer sculpotire. In outline menobreta resembles more close- ly T'ont acuta ? chip plana Dall (1), but that species is larger and (1). I-^eni, -p. 1171-1172, pi. 44, fig. 4. has a stout left cardinal. Occurrence .- lower Hiocene: BoTrden beds, Boivden, Jamaica ? - Superfamil;; . I A 0 £ A . ■family Oardiidae. '^-eii'- ;A?JDIUi.' (Linnaeus) Briifuidre. SulDgenus Oarditun s. s, CARDIiai {2'r"'^- ji^..i-j^ji^_,... n. sp. Desorj-jti in.- Shell snail, well infla.^-^r'. , si^'hem.iilateral, suborbiculax-, the lower part of the posterior i.ar^-iii slishtly suhtrui-^cated ohliq-aelj^"; unfoones tumid ai id, hnt not very high; external Ir-t^rce o" forty-three lov. _. i?l ribs, flat- topped, hut s^ifrhtly raised at thei ' , oarated by nar- rovver, sharply defined, channelled interspaces; each rih hearir^ r -r.-.n of laterr^ily compresse'1, trianp-nlar, " nr small, lioTlow ii._ s , their open ends beirx5" directe" ' the ventral mar-'...; in the raedian portion of the sliell ribs bearing- lar^-e spir.es and those ornamented with small spines altrirr. r-^t n--; anteriorly large spines p: " \nating and posteriorly sraall ones ; posterior marrin of the valve deeply serrate; internal surface with relatively con- 3pici:ous radial marking's. Dimensions.- lat., 23 ram.; alt., 27.4: mra. ; semidiam., 9.5 mm. '^emarhg.- 'rhis curiously scxilptured species is represented "■; - complete valves and sevoi-al fragments. Tliat is reaches a - ?-.^o - larger size than the type is demonstrat ant, -.Thich if eorh"olete, Tro^-'T'-l ''^.'^ve, a^^'iT'OTicatelj", ti- p ■''nil .-n.-iri"'' -^i'""- >i '■ i.ons : lat., 55 rani., alt., 37 iau. ; semirliam., 14 mm.; incideritally the hinge of this speoimen is cnriouslj- pathologic:^!, ocin,;;' inordinate- ly thickened and In?-. c' arirl refler-.ed tavard W- o ••ni'hn. On the larger valves the contrast hetweeii the rows of larger and snall- er spines is decided, although the actual difference in size is slight; but on the othe'^- ^his disparity '-'■'■• ' '-escnt, is not as notioeahle. '.Then the spines are ver^^ siiall, the ventral side, which is open ^■'hen the spines are lar-^e, naturally is clos- ed. As us^Tal, onl, 3,rt of ^-^'^c o-'i-^amentation is intact, vrnere the spines have been remove"! the ribs are smooth and flat, T^ith thin margins slightly raised; if erosion proceeds further, the middle of the rib is excavated smd the raised ..^^_l.„_. xenain as narrow ridges. ihe laterally compresse'-'', triangular, ven-^-ally open spines of two G-..Uxo of magnitude v.^ r,eioa "'"';-■- ■■-i '■><=•, c-- most charac- teristic feature of this species. Dall has descri closel- relate-'' form, _2» acrocoma (l), from the Ghipola; c" h smaller (1). rrans. V.'agner Tree Inst. oc''. ., "^^ iladelphia, vol. C , ot. 5, p. 1081, pi. ^.8, fig. 2, 1903. it has the same outline and a siruilar type of radial ribs which 91 also -Qear spines of tv?o sizes, but the la ' • cior-so- "e- ' rally covipresse'-l and hrve triinoated ends ..llcr soines are v_f> ,o-.-,p,^, Oo-ourrenGe .-^ lower Mi oe ene : Bowd en bee's, n, Jamaica. 392 ■ Subo-enus I'l-acli^-oarrTiixm Iieroli. ^ardin.m Inoonspioiiixm ^"^ruppy, 1866, '.iisrt. --. Oeol. Soc . Ion 'Ion, vol. £2. p. 2^", 1. in, -■^. ::. Oardii-ai inoons oioiinni '5upp: , 1074,. G-eol. Eag., decade 2, vol. 1, p. 442 f check list). Tot Oa^diic inoongpic-gimi --upp^ , 1j70, .ulu . "- . "col. Soc. Lon- don, vol. 52, p. 531 (=0. -loininicenGe Gabb, 1873). Oardlirni ( Trachycardii^in) xi_ 1 ou-gm _ , :r.ll, 19C0, '^rans. ■Jagner ?ree Ir "-. ^:?i., ■'■ ^ -^ _ ^ - ■ ;«, vol. ", ;^t. 5, p. 1082. Description.- "Shell elong-ate, siihtri^onal, ovate, or/cment- er? with nrmierous (38) inbrieate ' oroader than their re^Tularly sonamose irit ersrsac'-'^s; - .'. scarcel'- -ororninent; marrini-: strongly denta.':e; hi. ;all, .l-!-" '" ee teeth." '" ^y , 1866). ""' ie loealit;.-.-' Jamaica. ". . . . has from "thirtj-sir: to fort;7-t';70 rihs. •.vhich. ' ;: they preserve their outer coat, a heantifiil close concentric '-".rea.'^ing over the v;hole shell, e-:neTot tl:e rihs of th.:? -n.-st-Tior area, vjhich are smooth and polished; the loops of the threads - ?93 - as ■fc'i^ei' pass over the "boclj' rins (as n.sual in Oarci.iTim) are co" to^.'ard the iirahones. '.VehrL this coatir.?' is oy v;ear the top of the '"ih r/i 1 1 hf^ "lat a': ' '^-'^ v7hile their si'^^G shov: frin'"'- iiig v/rinkles. If erosioia attack the ' "aee, the structure of the shell ^- '-eed loops of the origins! outer coat." (Dall, IDCO). S'r.ell of raediiiia jiiae, tliin, v/ell inflated, suhequilateral, "broadly suhovate in oiitline, ''±-e crrve of the anterior '-largin heir:^ sli-frhtly more eonvp" t>'an that of ^""'0 ■■^octerior iiiargln; umhones lOT.'; extenial surface of adult shell sculptured \7i th fort^ or forty-one narrow, lo^, siihroimded radial rihs separated by usually vovy narrov; interspaces, anterior ten to thirteen rihs o ' ? ^ntecl v-1 th transverse or slightly o"bliq.ue nodules, posteriorly cho nod- ules progressively confined to the distal end of the rihs; to- ':jc^^ -- ^> '-enter of the shell the -'■'i'-'- "':,.•:: ' ,t -^ ' yo •-• -^^ ^ ^ -"- T^h 0 in th C interspaces the conce^.^rio tjtriae in'..'onspicuoLis ; toward the p'-;. t- erior end the similarly sculp' ' • hroader a interspaces wider; the e-' "■■'"'" posterior rihs lower ancl smooth, '^" - cept for a rovr of distant, fine, r ' ' -;Tly sh^rp nodules on their posterior edge; upper posterior rmrgin of the shell foeh- - 594 - Ij- serrate. Dimerisiong.- Lat., 25.5 mm.; alt., " ." m. ; semicliam., 9 ram. Re marl's.- Four valves of _0. inconspic-aiim are at hand, three of Vnese "be iii^- ad-alt and conaiderabl;; lar'^-^r '-'-lo specimen fig 11 -PP^"» inniatiire valve has onl;/ thirtv-foiir rios, both ribs and interspaces being wider than on the adtilt and the timbo slightly- higher. On adttLt shells the distel portions of a- few of the anterior ribs may be smooth. Ta.e no" " ai' not be eonfine" to the first ten or thirteen ri~ , further tavard the oeii ''•::. ^ of the shell uhj.^ appear near the distal ends of a few additional ribs. i^his species is characterized bj' its si^bn-" mtline, low iiDibonet-, Liid low, narrow ribs v-jiiiGh be "■ ■>--y^ straie. Guppy's doubt concerning the impossibility of separat- ing dominicense "i,bb v/as mded; dominicense. first described from oanto Domingo (l) and Is. i.fi- j^eporte" from Sapote, 3os--:a Rica (2), and ''at;m, Panama (?;), being entirely different, jJhe (1). Trar .: . Am. Philos. See., new sfr., vol. 15, op. 250-251, 1875. (r). Gabb, ■,'/. M, , Jour. Acad. l.u.'.. oci., Philadelphia, 2nd ser., vol. 8, p. 344, 1Q81. {■"), G-abb, ./, M, , idem; Joula, ?., Jahrb. x..-:.. gool. Heichsanst- alt, vol. 58 pp. 720-721, pi. 27, fig. 4; pi. 23, firr. 18, 1908, as G_. r'-Jrach; oaa'dium) p-at an ens e n. sp. (not G. fprag- Mm\ gativ.-ense Dall. 1900). fide Brown, and Pilsbrv, Proc. Acad. Hat. 3ci., Philadelphia, vol. 5?, t,. c.57^ 1911. \ pwst conspicuous f eati-ires of dominicense are the hif^h, full uni- bones, the lar.~e numTDer -^f rihs (fifty- five to sixty). The single Ohipola specir-en referred to this species is a somevrhat TJorn, imperfect valve ^ith the ant ero- dorsal margin longer than on the tj^ical ^owdeii f om, the " ' of the ajitero- lateral margin more convex, the median ribs i;7ith flat tops and sloping- sides so that Hie interspaces are wider; the difference in ornamentation is prohably due to wear. Occ-urrence.- U'rnex Olipocen: Ghi-pola, Florida (Dall, 1900); lower Miocene: Bowren oea, Soiydon, Jamaica fGupp^", 18 66, IB 74; Dall, 1900). 59 6 - OARBim: (T;.UOKYOA.iI)IUT.!) III::UAL:.^0I:I3 Guppy. Cardirun linf^ua-leoni;^ Guppy, 18G6, Quart. Jour. Geol. Soc . Ion- don, vol. ?2, p. 29?, pi. 18, fi.Q'. ". ^ardium liri;nialeonis Gupp^;, 137b, v^-eol. Ma^* . decade 2, vol. 1, p. 442 (clieclc list). Hot Oardium llnrijaleonis C-u-opy, 1G76, Quart. Jour. Geol. 3oc . London, vol. 7ji^^ p. 5?>1 ( = J. ^oniinicariaLni Jail, 1900). Qardlum ( l^r a chy c a r d i um ) ling-ualeonis GLippy, Dall, 1900, Trans. V/agner "ree Inst. Soi., Philadelphia, vol. ^, ■'■it. 5, p. 1064. De script ion.- "Shell elon^-ate, suliquadrate ; valves deep, ornamented vvith numerous (52) nodosel^" miiriaate rihs, which are lov/er and more distant tov^ard the anterior and posterior mar£-iiis ; nar?:ins coarselv oreniilate, the posterior one strongly serra':e; hinge \vith three large and stout teeth." ('^"vipy, 186G) . Syioe locality:.- Jamaica. "This svju jI-j has thirt^'-t-'o rih?-, "hich are closer to- gether than in the jpreoeeding specie:- f^. 3est;im JallJ , while the edges of the surmounting keels are undulate'', tv/isted, and rippled as confectioners do with rihhons of pulled candy. The shell is narrower and less ohlique than 0_. cestum." (Dall, 1900). - !^97 - Shell m Oder at elj" large, solid, long-itudinallv sulDovate, deciderll"" inflated; upper portion of the aiiterior lateral niarrrin ohliqaeli' sub truncated,. Icu'ver portion rounding ''oroa'"ll^' into the gently arcuate "base; Kiedian portion of the posterior margin suhtrinc ated or scarcely curved, the suhtnmcation extending lov/er than on th-: 'srior side and joining the base more abruptly; uinbones high, prominent; eytericr surface sculptured with thirty-one to thirty- three strong radial ribs re-oarated by narrow, deeply channeled interspaces; five aii'cerior ribs bear- ing medially situated, disconneoteci, globi'tlcr nodules, sorae- tines absent from the broader distal half of the ribs; the next sizteen or seventeen ribs ernamented v/ith a ra,ised frill placed on the posterior side and overhanging the interspaces, the orna- rac-_-.„,_on GOFiSisting of oblique, mer'ially swollen nodules with their extremi ' ' attenuated and Joine", prodiicing a spiral effect; toward the center of the shell the frill becoming narrow- er and sharper and the nodules correp"-'^-'''iri"'ly narrower and more vertical in position; beyond the center the frill becoming wider and separated from the smooth portion of the rib by a well defin- es, b^it slight, groove; on "^b^ ^,en posterior ribs the frill ceas- ing to be such, the line of nodules r lly assixming a central position on the ribs, the nodizles then:selves becoming wider, transversely swollen or globuJar -'>"'' almost or entirely diLrconnect- ed, these posterior ribs lower and the interspaces wider; fine - 3?3 - concent rio lines occasionally appearing in the inter; on an-" portion of the shell; posterio- 'in of the valve deeply" serrate. Dir'.ensions.- lat., J57 niin. ; alt., 48 mm.; semiri.i ., 19.5 mn. I\e!nar>s.- A nuniher of valves of this interestir- " — "i-en representative of the £. isocari'^ia Tinnaeus group is present. The sculpturing is very elah'^rste and on portions of the shell st: "7 suggests, as Dall \.uis aptly remarked, twisted ribhons of candy. 7/hen the highly ornamented ^rill is eroded the rihs are flat or suhrounded and smooth, except for a narrow r.e^ian stlLcus. Yor:-g individiials are less elongated and more orhic-.L . '•'an adults. j3, 1 in t^'iial eon is hbt he recorni^ed hy its sli"-htly elongated form and iioclulated, tv/ifste i frill ihat uvci-to_^ti ' ' '^oj: side of the strong radial rihs. Brovrn and Pilshry ha icrihe:" a Gatiiia form, 0_, ctiriatTrm (l), which is so close ' ould (l). Proc. Acad. Tat. Sci., Philadel-oVjia, vol. 6", ' . :-Sb7, ^1. 2T, fig. 11, 1911 (=2. spec, (vielloicht e Art) Toula, Jahi-h. i:.-k. geol. Reichsanstalt , vol. , . 721-722, pi. 27, fig. 5, pi. ?S, fi^s. l-^a, h, 1 . he better, rjerhaps, to consider it a var ' ' if liu;-n.aleonis. The only constant " :es are the smaller size '"he sli^^ht- - 509 - 1,^ coarser sc " e of ' '^m. '^■'' t th 1^ " ^ Mcli uouville (l) i.'LS~ii . z.i: j. lii.:'ualcoiiis. *hcL;e '. louville, ".; sur I'age '■iei3 eo'iches traversdet _- ?anal cTe Panama, Goiii-ot. ', . 3cl., vol. 1? , .497, 1891. t?.'0 forms, f^. e Ohipolan C. c^stum I-all ( f: ) , the 0.?]r '^rove 0_. r^el^ " 1- "•■TOi ?^al] (Z), the '..'accama.w and. CialoosahatGhie C_, emmonai Gonrsd (l) the iiioeene tr it 2.* isoQarclia Linnaeus (5) and t' -ant V/est Joaet 2« hrl^heri ■^roderip (6) constitute a v/e1 1 :=':pfi-no'-"' ^ro-n, the . ." -3 of which differ principally' ' in ornaricntatioii. (£}. loo- 3it., -, 108-, pi. 48, fie-. 14. ibcO. (?). loc. Git., p. 1064, pi. 48, f ip . 13, 1900. (4). Am, Jour. Conch., vol. S, p. 15, 187G ( =£. uuiricatum "'^rtmons. Oeol. :^ept. ITorth Carolina, p. P^Ol, fis'S. -^"--^-^ 1858, non linnaeiTP, 1 , (5). Sjrst. i,at., ed. 10, p. 679, 17'^'8; Reeve, Oonch. Icon., vol. 2, Gorfli.nm. ol. ^7, fi -■ . 8?-, 1"45. iaVo (7) recorded in the Saiito Doming'O oe '"'£;, th ^e of •: ("). i'rans. Aiu. l-hilos, .boc . , ev/ ser., vol. 15, . ' .. "n:-^;, ^^^hieh he identifi.. ,,^ ... --•'■ i" _:. _. oelonnatTur. _ 4t'0- SowerTDj/ and at the same ti ^-ace'"! linf^-ualeonis in s^'nonymy. As a matter -■" f "■'•'-, ^-'^ -> -^^'^ -^" ■- '■■^'-- -.^ "_■■;:: oh other ^i." from the recc '.^ . >. Eo-callerl eloi-i°-atxtm as G_. dorunioanum. irhioh has an entirelj" d?.fferent facies (1). loc. cit., o;i. 1082-1083, pi. 48, fi^ , ^ , 1900i from tl:- ^ -----_ discussed ahove, since it is more elong-atcf^. iiir- inequilateral, with twenty-seven subtri angular ribs, which are '"'i ff erentls" orr^^mented. Call's TiS-V^js is Ii?'-^le to cause confusion since Ga-o, in ohe paper imder disciiwaiLUi, ;-c'.i'. alreadj- described a fonn as G_, dominie er:se. There is at the present time no ground for citing: the occxirrenoe of lin,^ugleonis in Santo Domin^-o, since uuppy's citation '--r,,-\ ^.^^ apparently' merely an attemr;t to cor- rect (?abb's error. Ooeurrence.- lower Miocene : ,.._",; a en he's, Bov.'d.en, Japjaica (Guppy, 1866, 1874; Ball, 1900). - 401 - OARDimi ( X . . . JIUK) B0,V.DS::.>lI3i;; Dall. Gardlum r.iurlcatiim 'Suppy, 1674, Ccol. .- -, " \ ^afle 2, vol. 1, p. 442 (check list), ez arte, non Tin. Jarflii n ( Traohyc ar d ivm) var? "boir-rlenense Dall, I'lCO, ..z. Jagner Free Inct. Sci., Pliiladelphia, vol. Z, ot. 5, pp. 1087- 1038. ITot gardii-m ( Trachycarclliim) 'ho-'rlenenae Dall, 191 , ...11. U, ^. i:at. IIus., no. 90, p. 143. Pes G rip t ion.- "1"-''^. .qopoipr from t'- --^ larl and from the sile:-: oe's at Ballast Point, 2ampa -ay, Florida, was identi- fie'^ with the recent mariGeti.im hy G-uppy. It has about the same ntmiber of ribs (thirty-seven to f ort^'-'^^-i'^l fr/i tTi^ wonlpture is much the same in character, , oaf the siiiiilarities are all in Biinia- tiire; the shell is al'.Ta^.s small (alt. 15.5, Ion. 15.5, diam. 9 mm. for the largest seen), li,^.. l.^_^„^r prc'^'^rtT ,iiv:i tely than 2» Jl'llZi- ^atnm of the same '- £, v/tth the ribs more compressed and cro"'decl. J^. Luirieatmn has not been found in any horizon betv/een ?o""deii and the Pleistocene, ^•^- ^ '^h i*-- "^ra I^rp-t-T' - p.-'-.-m- -.n for doubting- whether the older shell is Identical \.l h tlie newer. I therefore propose for it the name of bowdenense, which, if conne-cting lini-rs should he re after be fo , " ■■ ' "''■• '"^•'•''ed as of varietal value." (Dall, 1000). - 402 - Tyy>e locality.- '^OT/clen, "^amaica. Shell srrall, nioderatelj' Inflated, slightly inequilateral, suborhicular, the anterior end heing more convex than the poster- ior and curvijng more hroaolj- into the base; innhones lov/, moderate- ly inflated; esrternal sculpture consisting of thirty-nine to forty- two low, suhrounded radial ribs separated by interspaces of the same width or slightly narrower, the interspB'''--:"^ visually crossed by ver-; fine concentric striae; ribs ornamented with a single row or more or less globiilar or slightly transversely swollen nodules; on the anterior eight or nine ribs the nodiiles largest and occupy- ing the entire ' ' " of the ribs; the nest seven ribs having the nodules progressively shifted to the anterior side; of the succeed- ing fourteen ribs on the first fev; the ■-^'■tit"'.c cr-c-^j^ occiropying the entire width of the rib and ventrally more compressed transversely while on the remainder the nodules gradually shifted to the post- erior side and the interspaces between the ribs becoming slis-htly deeper; the ten posterior ribs characterized by a narrow anterior keel and a lov/er, broader posterior portion on which the nodules are situate ''-, the interspaces t-^ t-^^n +:he posterior ribs relatively v/ide and shallow; posterior margin of the valves deeply serra.te. Dimensions,- Lat . , 19.5 mm.; alt., 19,3 ram.; semidiam., 7 rr-jn. ?.emarl:s.- Several valves of this species are ■oresent. The one measured is much larp-er than any of the others. The ribs on the - 405 _ middle of the shell are slightlj" ijarrower a-nd sharper than those on eithp"-'" f^w^ . '^he intprp'^oe hetv/een ''"''■ '^ i - -•- ^ oosteriorly ^ ■■^•^ the anterior ribs, on whioh the nodules are Oi- the anterior side, and the first of the n ribs v.'hieh bear the norlules across their entire ridth, tp-^'JR '-o >■'- ^^tT-'^tl^ ..: . _ ^ _ .e;.er '-han those ad^'oin:" , On ^oung shells the lov/ posterior portion of the ten posterior ribs is usually obsolete, so t::at the nodules re st in th ^ ^ ^^t "^ ■"• p "oace s * 1. bov- dene use is recog-nized by its sniall size, soraeTrhat in- eouilateral shape aiai numerous nodulated ribs. The raost closely related form is ■^'-" recent Jest Indian _0. auric at -jjh linnaeus (I), but, besides the differences po ' out in '■' - - -otation, tr.e 'D. Z'.Bt. ITat,, ed, IC, p. CZO^ 1758; P.eeve, '^onch. Icon. , ' ^'ol . 2, Oardiu-m. pi. G, fig. 33, 1844. Bov.'den speci-iens have more rounded nodules and none of the ribs bear two rovrs of nodules Y/Mle in nun- ica turn one to four ribs ir'.ime''^iately succeedini? the anterio"" -^^'^ ' ■' -■--- ,- ..oi-ir- .",^ixbly nodul- ated. The above t^-o species, the Vicksburf;;:ien 2.* precarsor Jail (£), Ghipolan 0. virile Call (") an-1 O. '^aT^ile 'Dall (4), f.M. loc. cit., p. 108G, pi. l-S, fig. 10, 1900. f'^^. loc. eit., p. 1086, pi. 48, f 1: . 1, 1000. (4). loc. ci^., p. 108C, pi. 48, fi^. 17, 1900. Oalr Grove 0, !:ialao'Tjn Dall (l), Oaloosahatchic and '■/aceamaw 2.* oclal- li7ra Dall (2) ^.iffer in size and in details of ornament at ion, form- ing a homogeneous gTO-i^x). (1^. Toe. cit., :o. 1087, p] . "\ fig. 4, 1900. (2^. loc. cit., -;. 1088-1083, -1. i9, "• . ^, 1900 {-0. miiricatnm Tuomej' an'^ Holmes, Pleioo. ?os., trolirji, p. £4, pi. 19, fi'--. 2, 1865, non linnaens ) . T4ae Tampa silex form seeiaa to be diatinot; it lis XAOxe inflated, not as much produced anteriorly, T/ith a more yy!iimetrieallj7 arcuate "base and slightly ^'.'idpr rii:)S, tlie "oosterior ribs cearing sharper spine b ox^ L'heir posterior aide. It should be noted that Gup^iy has not published the occurrence of muricatu.m in "Jamaica", >--S checlr-list (1874) ^irii^ that species from '" - - • ^t ;rinidaO. Oco-'rrenee.- Lower Miocene ; 3o'.7dr , a, Jamaica (Dall, 1900^ ? ?1' ■ '?■: ^rinidad ' , .-..-> ^ _ 4^^ - tj^,. uj.. Desoriptioj].- Shell j s.r ,':"". "^ , " borate in outline, p-^--^- ' "■ , '.r. anteri'j uiore con- verl^^^ than the posterior; i^jiihones fiill, moderately' " ' " ; external surface sculptured with thirty-five lou , flat, "oro ^ ial ri'bs, overhaxigin' narrow, cli-epl^- c" ui^^i.-T' '■■''■' ' ^-ces; the dis^-al portions of the anterior four or five riv "^.ing to he ohsolete, producing- an almost smoo"n, slir - ilated area; t'ne next ■^■-'--'-- three rihs haviiig icli.:., _;.].most microscopic, londitudinal striae and fine concent ic mar'Cin.g'S, more "•promi- nent and oblique on the anterior rihs of this series ^.tlc', arched on '':he regaining ai±^^, _ ^-es of -'-'"'■ :'" , i-lly on the anterior side, finely; nodulate:"; tl ' ': two oj o inter- spaces of this series not channelled, hut fiT' ^^osterior eight riho distally scarcely .. " "^■'■"' '"' '"■' " ' '""'' lines, the lines ht ;-: broader i " " o, the ribs being cro£ trica" " , ' ic z-^.T'.^e and the last thre- , n their rozimal half, small .-"Ic" ' " '^"x "^^--e valve feebly '^l half -^face '" ' - Tulrji runni:, -xv'.... ~Ji":;ensions.- T.at., .. ; alb., 6" mm.; semi ' ., r.^.-> - ^06 - :.=;i' , r "..- .: ?-_.':i' '" ,ola£;e of t" . ^ne o" 'ents ■ roxima.tel"'? s* ^n -\ '- 'jiiL. J. j.ic ; „ - . , . ; ., ~r . ; sernx- diam. , 31 mm. 'Phe fi ' - ^ . . . ' -i%i uS'j.L.'-'" -r a lei'B nrA on tl .•orti'^ns ings ai-'e .te.l lines rather than ctriae, except on the hlinviel^ arahcw .a-iid ;j.u i-ijcrvaia ^re a:i^raented so c.a to iTom undiilations , vhieh oecaeionally e'ctend almost s the rih ; the enr' 3 of these ^iiidvl aticns forn the riO'''Ti"'e ' , ^ '^h on this portion .f '" -1 ^ -o 'junti ■ ' ' ..If the surface is eroded, the ri- . - " hes-'rinj?; flat, iailDrica: -alec, '.'h-i^h c. - transform-^, od into narrow, ' . _ -'.ilea. "ar^-e iiidividuals the interspaces are erahly v/ider ventrallj'. J, vanf^hani is the form which i": re . .. fragment in t'ae i-ational i.lnse-j£i collection- -'-11 (1) referred (1). Trans. V/a&ner 'i?ree Inst. Sci., P'-'ila.del-ohia, vol. ?, "ot. 5, 108?^, 1900; pt. 6, pi 1587, 1903 ( check list ] . ).s "near ma mio renin Lanar-"''. It i : ' oterized hy the lar'^'e si - ■1Q7 - and broad, flat, almost smooth rauials "/hich are separated b^- Tery narrov.' intt.rs paces. Externally it bears a ^iblj? elo^.e /ePiemb'l 'nrice to _. :,"' 1 1 "pxl-'^rin (l), a r.-iceios' -^^-nn the Jaloo.-a- fl). Trans. vVagner Free Inst. Sci., Philadelphia, vol. 1, ^o. Ifl, pl. 16a, fig. 70, 1'^"?; Dall, i^^em" vol. 3, pt. 5, do. 10^0- 1001, 190:^. hatchie Pliocene. Ihe Bavden form., is however, j inflated 9nd .9.2 more tnxiid and hir-her umbones. In a:lcT\' ' _, e Pliocene species has a- more dcepl^^ ereniilated i: ' il ventral raar-^in and the sulci lerding up to the umbo are broader and deeper, but the 'ost conspiGuoiis flifffiren?e lies in the -nrpsenoe of an internal rominent ''rib'', v.'hivTh ex'jsi'ids from ohe vii^oo almost to the level of the V.;. end of the posterior lateral tooth; this feature, 'lioh ''•les been -._ ?? the '"'' ian'nnBtic character o'"'' th? cectTon -l:-rosteri£:ma Dall, 1^ eiitirel^^ lackirjg- in vaur/hani. Another, evexi more closely related ST)ecies, £. declive .--abb (2) from ''"he Go?'*'" ^ican '^■'i'^''e"nc , mailer, r-'ithout the {?.), Jour. Acad. Kat. 3ci., Philadelnhia, r r. , vol. n, p. .-^74, pl. 47, fig. 76, 1881. zngle between the postero-'"' ■'■^"■■1 ■■''■t'I -i-iO'^-tero-lateral mcr-^ns, r.l t'- : more rounded postero-lateral niarr-in and. base, and more coiiGioic- '-OUS internal radial lines; the sculpture is virtually the same. even to the nmnber of rilas. The above species are reprr.sentatlves of a group is typified "by the recent '.Vest Indiaii form "-■■' which the earliest name probab- ly is 0_. Ic uoostonu"'.!]! 3orn, but which '. ' ly name"? narmore'Tin fl). Tab:., i.-io. Caes. Vind ., . , ". ', . . G, 1R70. lamarck iZ) or subelongatum So'-rrby f5). ;ent sr^ecies has narrower and more ■" ■ -"-■-■-- ribs. ( ?) . Anim. s.:. ' - ; . , ic). Prcc. Zool. 3oc. London for 1840, p. This S"ieoies is named for Dr. T. ./ayland Vaughan, Chief of the Division of Coastal "^lain Invest i"-ation of the United States Geological Survey, ;-r ui. . .-- ::: "'''- investi- gation of the V/est Indian region is progressinp- rapidly, Ooci-rrenee.- Iov;er Iliocene: Bowdc -, v-ui., Janiaica. - 409 - Subgenus Pragum Bolt en. Section 7ra.';:'rLr.i i-.~. ;j. 3ARDIUI»I (?x\-vrM,J ±^1.. Linnaeus. Qaraiiim 'men iirm Tinnaeiis, IV^"^, 3vst. Rat., e-''. 10, >-). S78. Oardii:i-iii ijiecimn lixiaLieuii, -.eeve, lo-'i, joix-'r;. , Ico^:., vol. £, Oardi-um, pi. 6, fig. 50. Oardiuin Yennstiim Dimlrer, 1861, !:ol. "BlSt., •'^ol. 6, p. 77. Oar d i imi ru e ''"^ i u m linnaeua, 1869.^ .001:1:^ :-. -.ab., reixe ^utig'., p. 10?,, nl. 4, fig-s. 5-7. Oardi':''in ( ?ra,^-im) mediiun linnaeus, Cabb, 1881, Jour. Acad. I.'at. Joi., Philadelphia, End ser., - '. , . "'""k, 1881. Zemi 2 ai'dinm c 0 liimb : 'Iprin, 188Si, Tra;is. w'agner Free Inst. \] Sci., Philadelphia, vol. 1, -0. 9^, pi. 11, fig. 26. Jardinja ( graguin) spi indet., Jail, 19l'U, x'rans. -agner Tree Inst. Sci., Philadelphia, vol. 5, pt. 5, p. 1101. Cardixnn (Prsg-gm) medium linnaeus, Dall, 1900, idem, pp. llCl-1102, Oardium ( Pragujn) medium linriaeus, Glenn, ', "' ;;land Oeol. Survey, 1-iOG. vol., p. 522, pi. 86, fig:-. Ga,,b. Deocription.- The 3ov/den specimens are of medium size and thioloiess, outline roughly subquadrate; anterior margin rounding broadly into the base; posterior margin flexed outv/ard above. - 'Uj - subtrimcated 'belo'.v, meeting tho l-jaae at an an^le o :" abor.t 90'^; \m\- "bones tiimid., relatively "hig'h. aiid narrov/; -posterior carina otrori';-, suTDangu.lar ; upper portion of the depressed posterior area elevat- ed; p- tf^rnal siTfaoe s eiilpt itt e rl m'tii -hT-n" -,--f;- _-*:■' -i^o fortj- lov;, subroiiiide-'l to • " d radial rios, separated u^^ narrower, sharp- ie i'.'ijressed interspaces; the ribs and interspaces increasin-- in size from the ant'^'-'^r e " '-o '^^ carina; t^^ r-^ic-'nt to ■'■f-->v, rii^s behind the carina asymmetrically/ roitided, bein- " ^ ' overturn- ed toward the anterior end of the shell; luiv.orn snz'faces of the ribs showing arohe''-, ffTT-Titi-, -nro ieoti-n o-^ ■,v-^-.'>row eon'^entrie bands betv/een which are fiuei-, similarly? arche d s triae. Dimensions.- Lat., 28 mm.; alt., 54 ram.; semidiara., 13 ram. ?.emar'-s. - Jeveral ■^-'^1^--,= - v'>i,:. _je identi..... i "^h recent specimens of this long- ranging ki pec ies are present. 'Jhe ornament- ation of t>>e ribs is usually intact on only a few small patches, the ribs usually appearing polishes'' ^-■■•'^< ■'-i+'h ■^:'"''i oat ions of arched incremental lines. If this siir "a-'e is removed both ribs and in- terspaces are crosse'l by fine concentric striae, which, as usiial, are arched on the ribs. The Bowden specimens ognized by the strong, straight carina, the presence of an elevate'^ area in the rteeply depresse'' posterior region and the numeroiio hcixj-'J'.. rluo v/hich are ;.'eparat- ed by v;ell- defined interspaces. .Tlien comparcl with certain fossil c::-' recent forms of this s-pecics it is seen that the base is - 411 - straighter, the posteriu- ■-- not au ''je;.:a^ iiiciued, '-'' jo -.arrovrer : ""•^ ' , er and the ilbs narrower. -h? e 3ligh'" :e to the admittedly variah]. f riuediun. , 'LL-i-'e .u.- -. Torxi: that lihov; the same oharaaters as the Bo'^^deii s-peciinens. Oocurrenoc.- Lower I.Iiocene : 3a:/ den oecls, 3ov/den, '^'rciaica (Dall, 1900). I.Iiocene: . ar^'-'s forrnati , 'Dall, 1' ■lenn, 1904\ . Tin forr;.ati . : , " ■• , fLa^l, 1000). Pliocene: ./ao •_ ' ' , . "" ' ' , "-s.); Oaloosahatchie marl, 'Florida (liall, 1900). 'ii':: 3-^:e TiOo''cout to S,. _, 'arta, 3razil in --lan "0 , _ cer)t off West Inci.ie;i " 't occin's in botia olialloj^ a: p -.vater. ¥^ >/ - 41f2 _ Desc- .- '" ^T ' '■' , -, •:v3.teli- inflate^; oerior ni ' , oroac"' ' , ' ' "' '■ riorl;-, base very ^-ently 3.TGneJ:e ^ ri- :erior raar,'];in . ," Kieetin?: the ^ostorio ■ in at an ann'le O"'' 00'"' nr rno'-e; 'Tih nari-OT/, n ' ' ; ^terior earina siodora'^el;' ctrori^-, : ■';- _•:'"^-..Ie" ounded; exterior siirfacG seulptr to tv/eiitr-on'. j.al ribs oi: 'jion o:^ the nheTT anterior to the cari . ' ' ' t to te: ^ ' ' ^ ' ' •; carina; inter- spaces as vrid.Q as the ribs on the ce. ■f the shell, bpt nar- . mwer in ' .jterior area and 1,:- . oyitrc - ^ - - egion; the ribs bearing at relatively dista ' " '^ervci.ls '■ 'e or rounded n' ' , bet :'.•■■- en v:hloh y ery '' ' : may a'vnpar, th. ' .ers'oaces ovor, pp i b^" ?^hr>T-v^ ^i^rrr ^ ■eritri''' ■ "evated lines; ixpper po.sterio-v ' ' ahe valve Tcebly serrate, Dinensione .- Lat., 7.9 .; c.it., 8,1 mm.; semidiam., 2.i' neraarlvS.- -.. nijj">'~''' ■'' ' -,.„.-i. ^ , ' pvpral -"'^i -^h a^^ear to be adult, -^zr^.iS t':e h 3r th' .Jito. As usual, the outer siu-face of hell is "ore the r■l,■\n^^^^ ,->r^ ov-^i\ fine concentri''' ^--frv'^e -i" -'''"-' ''"'' ^- ^'^rely seen; indeel, the ribs are usually much lispl ry fine concentric striations that often i- in the inters-^iaoes ■---tween the coarser raised lines. A f-\v 0-" "■ " _ ,_ o'.o:. a tendene;/ to h-ye ^hc -os eric fcl^ ins' in t" ' ot tl . fr-e assofi' 'inpg; ov.' ^ ilj' oe 'listir:^"^! " efl. froEi :■:.'■ .-■. of the sanr ■ ' ^' , ' ■ less ii-ifl^.L less sharplj- ca.riiiated, vlth Ic . rL^bs. 2_» elattooostatfirn is verj- close to G_, "bamsii L'all fl \ a conmon ^hipola specie o, ' " ,"■'-' '" ; " . .- il). Trans. V/agner :?ree Inst. Sci., _-'.-i:. : ^: 1-^hia, vol. S, ot . 5, p. 1101, pi. 48, fis'. 15. \^lth hij-her and narro-'wer urifooi.'.tt , ri'.'iu '■ i, fevT r rii3s, deeper interspace ■- ^ric " ' 'ater- spaces more riron^.inent. The Bov.'den f' , _i_, for r" Dall has pointed oat; the rela l^Iuu, iutennc'"-" '" " jqh tV- '" 1- cal Fragiim and [I'ri^oniocarr"'ia, •■■ ■ - • ribs of the former and the striated inters-naces of the latter. Occvrrence.- Lower Miocene : "^ov.den oe'-s, ^.owden, Jariaica. - '1-1 Section liocardia '^all, .O^uiDIulI {T21G0ulC 770 rbj^. Oardirjn H:-i tense Sov/erTD^;, 1850, ■■■'-. :---. Geol. Soe. Lonr?-:., vol. G, p. 5g, pi, 10, fi£". 11. Oardium ^-^'al tense Sowerby, G-upp:;, 13 Co, '^uart. Jour. Geol. 3oc . Lo.idou, vol. 22, p. S9S. Oardium f grapg-mi) llaitense Sowerby?, "-abb, 1872, Trans.- im. Philos. 3oo., new ser., vol. 15, p. 2 51. Oardium Haitense Sov/erby, Gupp;;, 1874, Geol. ^-a-. , decade 2, vol. 1, p. 442, (elieck list) ex parte. Oardium Me i tense Sowerby, Guppy, 1376, '^.uart. Jour. Geol* Soc. London, vol. 52,. p. 551. Description.- "Testa oblique subovata ^ibbosa, radiatim costata, lateribus brevibus, eostis ouatuoi" ct viginti, quad- ratis, ,p-raniferis, interstiis creberriiie rugulosis; anPTulo post- ico rotundato ex umbone a.d marp-inem inferlorerii posticam decurrente, (cjower-y, 1850). Ty->^e locality.- Santo Domin2"0. Shell of mediujn size, heavy for the size of the shell, strongly carinate, decidedly inilateci ; posterior niargiji " ;t vertically truncated, meeting the ventral margin at a subrou:-'''.- ed angle of about BC^ to 85 ; umbones tumid, hi^h; the loortion _ '1.1 ~ - of foe shell anterior bo che i)u>.iL.';xlor cariii. - --•.---- thirteen or fourteen high, flat-topped radial ribs, .separated bj' sqiisrely impressed, deep interp-oaces of virtnall:' ■'■he same width; ai'eLL ijtihind the carina beariu^ nine radiMla oT >ji.-/ "' ?ter, the interspaces being usuallj' narrower than the ribs; ' . the inters-oaces relativpi;^ eoarse, ooncentirio threads ^resent, arch- ed (with the coiiucive aldu toward the umbo) in the " ""l- atelj" anterior to the carina and also in the posterior area where thej" mav cross the ribs; some or all of the ribs nodn.late'', the nodules beiii^- globular in L'he luubonal t'.n'l 'Jas e::tre:!ie Li^-uerior and ^■)OSterior regi f the shell, and transversely swollen elsewhere; tiv? first nine or ten ribs 'ororrossivelj? wider and. the first five or six intersoacca wider triari elsewhere; the remaining ribs up to the posterior carina usually squarely Iceeled, -vYith the con- centric threa'''s of the interspaces present on the lo" rt of bhe rib, but not on the keel; immediately behind the carina both ribs ajid interspaces narrower than elsewhere, bi^t increasing slightly in width t or/ ard the posterior end; internal margins of the valve ' ''' "hort, broad erenulations. Dimension g.- lat., 18.5 ram.; alt., 213 mm.; semidiam.., 9 mm. ^emarhs,- This S'oecies is r en-p r''-rabls "oroli ""i c ; it not onl" far oiitnwnbers the other cockles, but it is the most abu.idant pelec; pod in the f auj:a . Despite this unusually large re-oresentation the characters are for the nrt^.t -op -rt r-'.iite constai't. :^st marked variation affects the sharpnG;Ss oi' the carina. In general, the - 416 - cariub it. sharper on right v.ivt'a than on left Oi.eb; ox: l^ulis sitbII left valves, however, it is pronoiiiieecHy angular and the C'^rinal rilD maj be slightly exaggerate'' anrl such :^ . ::;pi-oach tlie variet:" xa:,T.iacenae. althoun-h they retain the orincipal char- acters .of the tj'pieal form. The numher of rihs santerior to the carina r.iaj' he as low as twelve, but thirteen or fourteen is usual; behind the carina nine is the predominant nuiiiber, although eig'ht or ten may be present. The nodules raay be absent from son© or all of the ribs; in fact, no rjin?-le specimen h-^s all of them intacc. ..hei. deprived o' their nodules the ribe are, sraooth and polished, but have suggestions of incremental lines. sur- face of the ribs or interG"icces is remove'"'', both Eho'v -^ine con- centric striae, finer than those on the unworn inter. . ::^i interesting feature lies in the keeling of the ribs '. i.tely ai-.terior to the crrina. These ribs, althou~h 3.ctuall -."if^e as those proceeding, appear narrov/er, Gin';e the flat-to; corresponds to the entire width of the preceedir.g ribs. The keel decreases in vrl'^th "oostfrrim-j ;;, 'Roth th (- Inr.-rr -inrti on of th^o rib- and the keel it.oelf are usually square. A vory narrov;, G..'.ooth area, more prominent on yomig shells, separates th rior i^or- sal margin fr.-'-^ '-"c "irn't rib. ?' ■- ?'' istl.. ' '. ^ :.re of 0. haitense is tixe sculiotare which consist -jlly twenty-three nodulatec", high, square ribs, v/hich are separated by concentrically striated, deep int erspaces -of th'- -■^^■n <--,it>^. Ttp tT -; -hr" iv^-^i on - 4-1 7 seooion occur in ''lie Jertiaries of the OariblDe: its perl.'ietei's : in fact, the section is confine'-'' to these areas. Ainong C-uppy's Trini'-'^ar^ r.iaterial, nov; at ■■'' ~ ». (Tji, are some sneeinens from the "Pliocene" (l), v/hioh were labelled (1). Jail (Trans. '.Tagner ^ree Inst. Sci., Philadelphia, vol. .?, pt. 5, p. 1105, 1900) snp-jested that the horizon is lower. I-Iai tense atid a-^parentl^/ were includerT hy him under that species in his 1S74 check list. ' r^.e fon^is are distinct ' riaitense and •^-'^"■■e •'''^-oriTDe'^ ''">;' '^'?1"' _. r'^qt^TenPe ; ''"^ l-' "maimer, with lov/er, "oroeder, r::ore rourided rihs, heariiig nodv,: -^iS v:hich V iC ; • • • , p . ±x^-'0 f - • J If^ • ( J J. ' V' . do not extend entirely across the rihs. 2.* ^ as turn f^iip'^y f^K f^om the rOooene "-^ "ansanilla, Trinidad ia less sharpl; ■ '"ed, aiid the rihs are lov/er. 'I^he Ghipolan sinrrpthi Dall (4) is siaaller, f^l. "uart. J- . . '. .0-. "-r:-^"-, vol. 22, -♦ --", --^ . "-, fip-. 4. (4), loe. oit., p. 11'-:, pi. ^ , xig. , "^ . more qixadrate. ".'ith f and "broader r'" . r.'t tri'"^!.-; - -^.TS "reDresentative section, 0_. anf: II" _ ' - ^ ' '" \ ir. (1). In de la , " ". \^., olit., -t . . --^e I'lle de Ouloa, LolluGci-aes, vol. ,2, p. S0$, pi. i:v , i'ip.-s. 53-55, 1"' (Jreiich .eel.) (I 2* Qeraraidium -^all, ou.ll. Kus. ^l-^-'ot. Sool. Ilarvard. vol. 12, p. r;60, -ol. l-, fig. c^ 1386]. Br.ialler, proportionately wider, T.lth onlj'" eig'htee: -.tj"-one no re rounded and differently? ornamented rilDc, of T;hich the four middle oiies a'^e '-vii.^It ") -j rr'^ r t^r'n "^"'■"p .-if-e.r , " ■ ' ■ ;__ tile o--eoies Wuioli Gup/^ had in iiiind v.h.en he rei ) haiteuse (2). !_.. ._:., I'l'^^: An. . --^, -'1.«t. p^V ftp-., '^oT. -^ :;o, 15, p. 51, as living in th '" Indian --vate"'': . Sowerbj-'s larger fiffure is s^ islee^' , 1' a i tense is more v-i---.-iiri-i--. o,-. -^i - t-, ■ ■ ,, - . '-^-,a■ --, -■-^,^, :--■ ,-.-,- and r roer than would he ' "' re; in ■ '' ' ' '^1 vi _ller valve i s '■•■".o re ae "^ " " ■ :' ''"e . Occurrence.- n-'-.-,cr Olip-oc ' : • -, loYc;; .._.,, X ., -- , - :j- iiOc J; v/. :,..a (C-up--^:, 187-4); Guracao ( ^all , ; Lower Iliocene : -c -.n hedc, ^.cf.-:d.e'nf Jamaica (Oupp;?, , -11, 1900). _ 4.1 9 - I^eso ':-ip-!;ic;. .- - - ■ - ^ - • - ■ sal liai tense . but ; itli thw e ' ' ^n o.f f- r -'"^n ell 5 ri -h e f^ o r "f^o the og,ra"na scTilTititr^ "l■^ ■" i.ot verj^ dee pi, •iatel:/ more ro^^'^" ; ;■: . . lar, "out najL'ro\7er ribs, the ribs, ribs orna'i'nerit -s, r-lo"''''''''?"'-'* 1811 ver. i-"' i-egion -:; with relatively "oromiaent or '.11 the t:'"^ioal ha i tense. -*-'ii ^ * f J-X l.ilil* y trV-1- ^ • J Remarlrs,- .'"lis variety; is proposed for snail ' ^h olo^el;; reeenible haitense ' . -' ernphasiai.- ' ~ ' ' 1 \ " - rib '.vhich ■. ;■ wider, ^ ad more roiijided than those Qi^Q'^ ' 2 slir"ht increase in thr^ mn^bcr or? rib? ipbci " conconii'^ ' ' '.on in "jhe - ' inters'f:--C'-ju serve t i?.riety from the , of t' ic?l haitense. Fne :~ tenr^e csrina more : .,'iUlar than ustial and the carinal r" - • - ■ - - -• --,-.._- from the varie'' ^ ~ ving" tho ti^bs o:" ^ ' ii?al '-:- i'jCii -:g . '. . ' . "^e higher and the i ' c wider. In th.e case of the variety under discussion 'is -11;^ more "ororrAnent on left valves than : ' ' . is especially pronoimced on in:niat^ire valves. At ' ' ti;iie th.e exaggeration of the earinal rih tends to cause ' rina to he ""on^^r th?.n "'.n the typical h a it ens e . thus caix?: ' t ^oroiL^iG uiOii QL ;he engle iDetween the ventral and pos" " ^ a fecture v/hich again is more rierhefl on immatiire valves. The yon.:-- of Z_, [ ?rr'-",ujnl f^at'^nenge Lall (l), a species from the Gatun hec's oi Jr'anasia, also characterised hy a p:. (l). Trans. "Jagner Free Inst. Sci., Philadelphia, vol. , 'z , 5, p. 1100-1101, 1900. inal rih, " " " ■" r from the iovvden foi-m "by having a more oblique poster'. i^gin, a narrower posterior area, v/ider, lower and niore rouiy^'^ri ^^if^^-'' ' ^i-, tprior 7:'vhn^ separ.?""' ' "\, 'h nar'^o'.' i-r interspaces and a prominent smooth area i -ly "before i behind t'le umbo. Tlie Ohipolan G, alicula -Dall (2) of the sarie [?.), I'Vm, p. 1103, pi. 4^;, fig. 5. ; Lse a,re narrower -^.-vco^i ^ ■ '■>, fy.A. -.Mrir • ■:■-,■.-■ i-.n r■.^ ^.r'\_r\o- - 4 21 - .icuel; ;- ,-> -^.•\--^■•-a ' n V -:; . ■'■'er ribs and narrower int ea'G-oaces. 0 c e oxT on o e . - I^ow e r Hi o o ene _ , .3 ov: cl en , Jariiai ea . - 1 OAaDIUlvI {TRICOi:iOOAI©IA) TiiAm'TASTLliL n« 2":) . -Deserioti on.- Shell small, o'blique, deeicle ^.1;- inflated; ant- erior niargin roi^nding broadl;; into the gentlj" slopir.o- "base, o"b- liqnely triznGated posteriorly; itmbones high, strong " , osog'jrate; carina very strong, curved; portion of the shell : ' -r to the crrina sculptured with ten, relatively v/idc rihs, increasing in sise from the anterior ;,:ai--in to the center of the shell ar.'d then slightly decreasing, the oarinal rih heing stihroimded, the others flat; the interspaces ai^teriorly narr9"."er than the rihs, to^rard the carina oeconing hroader and much deeper; po-:, cu ' icr area much depressed, omar.ented with seven narrow, low, flat rihs, wider toward the margin of the shell; some or all of the ri> a^^.onted v.lth small, globular norlules, becoming slight 1;^ •. rii.....veioel^ elong- atoi in the median ventral region; interspaces vvith fine concen- tric stria'^i'^n'?; imTne'" lately before the umbo narrow, smooth pre- sent ai.id oci-ii^ci che .„oo a siiuilar area ijcarce"' " ' ff erentiated from the lo'.v first posterior lib. Dimensions.- L::t., 7.0 r.im. ; alt., 10 ::^m. ; idiam.. , 4 mm. 3er:iarkh;.- ' le right valve of this bea.ioil'ull;, sculp- tured spe is at hand, ^t is distingrdshed by its small size, oblirne s'-a-oe, stroi-r:' c';irvGrl carina and the deep intervals betvveen the ribs which i..ime ' iately preeeede the ■■ . is species can not be confused with ha 1 tense or its variety saymacense because of -4 23 - "IfferenjeL; 1 -'<. tiQxil-gtvre. It is v exv t/ close to the liaxito Domin?rian J,, amlnense Sail (1], but that (1). ^iTaxib. ./agi-er . rec liiat. 3ci., x-'hilc.ciel-ohia, vol. 3, ot. 5, p. 1101- , pi. 48, fi,-::. 5, 1900. speoies is larger, with higher and less gvrate uralDones, less curv- ed carina, more numerous ribs, which posteriorly- do not become conspicuously? wider. 0_. spate ticiaii Jail i' 2 ) , an Oalr Crove form, (.?). idem., vol. Z , ,;t. 5, pp. 1105-1106, pi. 48, fi.- . , IDCO. differs, b;^ having slightly- higher and narrow umbones, m.ore numerous ribs, wtiich on the bor!y of the shell are lov.-er and broader and the interspaces between them shallovver and narrower; in addition, it is apparently without nodules. In the Johns Hopkins University? collection of material from ■^"'''■^ '-•-o-^.:-. ^-ip ^ ^ ,-,-<^ Panama (") is an (-), Collected 'by Dr. Marcus I. Goldman. undescribed Trigoniocardia which is rather c Igsel^'- relate"; it is narrov/er, the carina is romided and straight, -sterior area less sharply impressed, th'^ -.'t>, ■ ■•■■lOTe nu'ieroiis (eleven or twelve on the body and seven or eight on ' lor area) and the inters-caces narrower and shallower. - 424 - ^CGiirrence.- I aver Hioeene 3o'v7den beds T'.o- TfT eii ^'araaica. - 1-25 - Sub-enus laevicardiun ov/aiiison. aAHDIUlI (LA27IG.V^:jIUI,:) :;tUM Ilnnaeus. Oax-diuBi sei-ratiim Linnae'.'S, 17"3, '^l^t, I'at., ". 10, p. 680; 1757, idem, ed. 12, p. 112?^. 3ardii7m oj-^.ri ni-ira serrat ',-m Ohenmits, 178", Or>r..v-- . Q^i-y , ^ v^l. G, p. 194, pi. 18, fig. 189. Oardiiira citrin-ain ',7ood. 1815, "en. Oonch., p. 227., '. "4, f is- . 3. Jar'^j-Ti: laevi^atum Lamsrclc, 1819, - ' . ^ r*-., vol. c. p. 11 (iion linnaeus, 17 j8; non Born 1780) -£. Gorratiijn var. laevicrattmi (?). OardiiiDi serratuni linnap^^'^, "'.eere, T'^''-^, Oo-mV, X or., vol. 2, 3ardium, pi. 1, "if. 1. ^ardium ovip'-itarnen .^eeve, 1844, idem, pi. "', fig-. 76. 2 ard iiira s err atitci Linnaeus, d'Or'bifin^', "'" ^ 'T^ , '.:■'- 'e la "a2"''a, Iiist. fis., polit., ^ natur. de la Isla de Cuba, I.'olus- cos, p. (Spanish o".). JardiiT.! "erratum linnaeus. d'Orbigny, 1846, Voy. Ainer. Kerid., ::ol., p. 59". Oarriiiij:] s erratum Linnaeus, d'OrlDi , 185,'?, in de la Sagra, "ist. pl^E., polLt. et lie. _. > .. . - u :'Ile '.e ^uba, i!ollusc[izes, vol. S, p. ' ■, (drench, e''.). ~logardiiiTn pi^tum ?aV'-^nel, 1862, ?roc. Ac?.'"'. Lfat. Sei., Philadelphia, -'■- • ^i:i, ij. 44. CerdiLTin vennstum Oe:^-h^ 187:^, . Am. Philos. Soc, G'-r., voi. ir, ij. .'.'1, ' _. verms far: ^------■■.^^ 1361. Gardiimi (laevioarilixTa) serratiiiu la.. , , 1381, Jour. Acad. ^"at. Sci., Pliilar'.elpliia, ^n^ ser., vol. 8, p. 7.74. Q.nrdinia serratiim linric -a, .^all, 1 1, ^llII. ::..- . Oonpt. Zool. Harvard, vol. 9, p. 1?,1; 1886, vol. 12, p. S70. O.qr^AiTm R erratum Lin:. , C>T:ippy and Dall, 1895, ^"roc. U. 3. lat. F-i'c;., vol. 19, n. -'-'-. Jardlnm f Laevicarri iiTm) serratum linneaus, Lall, 1900, Trans- vVag- ner ?ree Inst« Sci., Philadelphia, vol. 5, pt. 5, "o-. 1110-1111. Jardj-gm (Laevicar'^itiin) serratimi Linnaeus, Dall, 1901, Proc. U. 3, ITat. Mus., vol. 2 3, p. -587. Qardium (Laevicardium) serrat^xm Linnaeus, Dall and impson, 1902, i'''*^ Bull. U. S. Pish Oomm., ' . -";0, pt. 1, p. 489. Laevicardium serratum (Linnaexis ) Bo-:, 1906, Bol. Inst. Geol. niexieo, no. 22, p. 30, pi. 11, i'ig. . ? 3ardium (Laovioardii.m) dalli Toula, 1908, ." . K.-k. geol. Reichsanstalt, vol. 58, p. 722, pi. 27, fir-. G (not C. (Traohyoarni,j::i} aa-.li lieilprin. 1887). Qardium f laevioardiujii) serratnjn Linnaeus, Brown ilsbry, 1911, Proc. Acad. Ilat. Sci., Philadel^^hia, vo': . 63, p. 367. ? '3ardium (Laevicarlium) -'^.al li J- .-la, ^ Pilsbr;-, 1911, ir^em. Dc scripti-u.- The speciniens referred! to this species arc of medium size, frf^ile, v/ell inflate"^, usually obliquely produce""' .A?? - posteriori;.;; oiitl-'. obli' ovate-tr' 1 to almoc ^l'->'-i - '-n-^'-^- -, n vr. ''-terior we' t'-t '^ o>)lif(_uel;,' oubtruiic :tl„; rouiicled; ;trioall: arcuate; umbones tiinid, moderately h'. riiia dis- trail;/; anoerior and posterior ends of the shell ■ ' ' i radial markings, the posterior area oeinr- 'r/idcr than t .erior; the reinai"- ' -"'' ■'*■'' '^'^■' '-• ~""cll "^ooi-n -,-,?>• nunierons, :, dl. , . Iil'^ radial markings; entire surxac-e of the shell wi'^ centric markings, in the iimhonal re^'ion more re^-nlar" -oars- er; thi^ hiix'-i. ' ■'■ - ^'--^ -.-,'.--■'■■ ^ - - - ■ - Li_.l radia^ls minutely' erenulated; .yen';ral half ox th^ rrel s^^r^aoe with rrr.. faint radii. I)imen5i ons.- Lat., .; " ., •; ■ t ^'^' -"'• Remarks.- "/it Ir.vo of the present Bowder: of this long-ranging species are large end t;'"oir'o"' ' ' , the valves hsv''.-' •. outline that i-ui-tis ' t-l^ elongate to almost sulDCircular. The e'-^ternal radii could .soarcel^" "be tey rihs since the;;,' harri] '-ct the co-to-nr es of the sl^ell. The s\u __ . , , -M^ y both ^h radial and concentric markings stanri ' ' 'c-lief, prodiicin," a cancellated effect. 0_. con'rprgssu.m Dall (i), 'ip'ic- . ' ■•,--. ^ -"- ^ - 428 - is readily '^ ' ' ' ' ' "" ' . " ' "apressed postci'ior are " ': proc^ :ation of the nar.^-in. lin and v7acca- Mav.' i2» ^^'.'".3] 1^ - :-i vonrp.d f *!" ) i "^ier, ^ .: (^on- (1). loG. cit., pp. 1109-1110, pi. 18, fig-. 21, 1900. ver: and broader. 3_' i^^'"rtoni Oonrad (3), rangira "^ '.'.' o~ fr). ,. ■ =^. A-pr. r^PoT. -r.fi ITat., p. 110, -1. ^-, -^i-. ir, lO'iP, ("). Jour, Acad. iiat;. Lici., Philadeliohia, vol. 5, o. ^59, pi. Gene to .ecent, is more rotij'.de''' and more compresFi: ■" . Dall : ^^^rted (-^-^ ^vr,.n ''o-^r _^. -orr^^ .„ _. ':.ari- t ic uia ii?ll (u) , a recent dee-iier water variety," . A!' '" -i this (■.). In Gupoy and Jail, Proc. U. .,, ....... .._,...., ,.1. 19, -o. "'^V, 1896; loe. cit., pp. 1110-1111, 1900. (5). Bull. ::iiS. Oom"Dt. Zool. Harvard, Vv-L,. :^-., -i.. 270-271, 1S85; Bull. U.'S. 7ish Oomm., vol. PO, ^t . 1, "o. l-Pg, -.1. 58, fifr.ll, 1^01. smell form is slig-htl;" more compre^.-v. ■ than the t7"pical shallow? v/ater s erratum and with slis-htly hig-her inihones, the principal ■"istinction lies in the pin""?: colouring on the nmho and therefore it seems ha25ardous in l;!-c z-v.^^- of the fossil shells, to attempt - 429 - r!istiji'-(iisli the varietj- from th ^ ' ' 7l serratr-u::i. The Sr^.r.to ^onin^-ian Laevicarcliuinf-T nnder the name 0_, veniistitg G-£:';u ■ ■jj.jrssentatives of tliia ajjcaiev-. . Toiila's Gatim £• 3alli. a name preocctipied "bj? Heilprin, ' ~ " ly sorrgti-'j:. althoiA'^'h it a]p:iears to have more prominent radial ma.rkings. Ooe^irrenoe .- Upper Oligocene : Santo Domingo (Gahh, 187"); Satim formation, Pari-^r.-ja {? ?oiila, 1909; Brovm and Pilshrj-, 1911); Lov/er Mioeene ; ^ov- uen oeds, ^-o-.vden, Jamaica ' p^' and Dall, 1396; Dall, 1900). Miocene: Ghoctav/hrtchie formation, Florida fDall, 19CC). ^lioeene. Santa "'aria Tatetla, Vera Oru%, llexico; (Bose, 1905); Jaloosahatchie marl, _'loriaa (uall, nCO); li.iion, /l Oosta ?.iGa (GaTDl), 1881). Pleistocene: South Flori' ^ " Antilles (Dall, 19^0). Hecent: '"eras to in 1 to 75 fathoras. _ /I rr-i _ Genus _... ^....^I.i .je.yrich PKOTOGA:: .- . ..^..^..,.. ., 11, Protocai-dia -aaaicensis Dall, 1900, rrans. -:T ?ree Inst. 3ci., Philadelphia, vol. '^ , '. :, ^.. 1114; 190r, "ot. 6, pi. 48, fig. S. Descrintioi:.- ''Shell small, pluji.o, .mlDqizadra',^ , , ith rather high snhcentral umhones; anteiior end evenly re ' , osterior very slightly rounded truncate; surface with very numerous radi- ating threads crosr- - '^y concent'-^'' -" lines eve.il^ lispose'', v/hich at the intersections reveal themselves hy renderii radii headed; this sculpt^.ire covers a little less than the anterior half of the disk, behinu .rhich the a . < l^ula , l.^-u -.^rrower and not head- ed, separated by still narror/er channels; in the channel seoarat- ing the anterior from the posterior type of scul-oture rises a lov/ crest like a stri:-- - -^ -—"l" j.r'.uj, u;. ' ?h in each second or third channel rises a rov; of small, stout, veri' cadu- cous srtines, those on the :." area smai: ad shorter than those on the disk; internally the margin is minutely serrate; "-'■ - hin^e is nomsl. Ion- .", "'., '..:■, 'iam. 4.5 mm." "This species is nearest Protocardia 'oeramahilis 'Dalld], fl). Bull. llus. Oompt. Zool. I-Iarvard, vol. 0, p. 1""? 1881; vol. 70, pi. 4, fig. 7,186" ' *ardium l_ i V 1 '^ ^ _ A"^! _ a reoeiit deep-water species of the Antilles, bnt d.lffer3 "by i'; 3 smallnr size, more 3^ el i -"^j^- t e r.ov'] ■i-'-.-.rce , " m^-'-rous rov/s of e-i: ::?'. I': ic -.l.:.- '■ ' " ' ' " . o'':l:^er liv ' ' ''■ ~ ' : r.pecies, P. tincta Jail (1), by its s: ' : 1 vav.o\i smaller (1). In Dall ' 'impson, Bull. l.. i. .. ' ., vol. EO, 1, p. 4' . , 1. 58, fi,^-. 7^, 1901 (-^. . - - lal arnabil' tinotiir.g Oall, 1891, I0-. sit., "o. 135; 1"8G, loe. oi-., 270.). size." (^all, 1900). Type locality.- 3ov;den, Jama.ica. I'^emarVs.- -i^his species has not ap-oeav the collections at hand. OcQiirronoe.- Lower I.'iocene : n he^s, Borden, Jatnaica (Dall, 1900). - 4; ..^— -DIA sp. indet. A second Pro-L-Qoardia is r. ,, fra£rr!ient of tho posteri-"'' ^ -m'-^n ■ ■ Tr-^i-rr.. xt is vMioh lar£^T;r tiian J ar.-.a i c e j i s i s v; i th tiie int ei's^^aees , decidedly vTidor, the ribc and interspaeec " ^vial, the spines more ohtuse and the con- ■-^giritiric 11 ■" ■ ' '^ '^ ''"''■ '"" "^ "^ -■ ' '^'"■'■' -1 -.':''-•->•■-'.-•- ^ .' ' r-> ;-v ■--■•, w. -,-,.> ^ T-(^ a"'>'^oTs to re'oresent a fonn closer to the rece.; ' " 1 ^eoies tl-^n is 2 ar.i.ai c enB is. ?ecr-rren?e .- Iw/er Miocene : ^ beds, '^ovT'Ten, Jamaica. - '=■ •^■'■-« vn-^-rr..-,- ^ ^ :-^ocogyrate ; luxmle large, impresr; ", ell-d ef ine d, out v.itii no cleiineS ec- catcheon, posterior end pointed,, anterior enc5 roimderl, haoe areuate, r-^ther prominent me sialic ; /^•'^■-■'^e r' cnlptiire"'' 'a1 th eon- oentric striae with flattish v/ider interspaces; hinge norrsal, rather heav;;, inner margins entire; pallial Ginu:; small, angular. Lenght 4.5, height 3.5, '■''i arr.e •-'^■^ "^.0 mm." •'The small vslve from which the above '■■description is rira^ira up (the r'iameter as iisiial being twice the er ox the valve) is lip to the present time " csentative of the gen.iis knov^/n from the Bowden marl. It is doubtless iiiimatm-e. " (Dall, 1303). ?ype lo oalit--.- "'-owden, Jamaica. ?emar":s. - 2hi s s t rang e s pe c i es is w ell-r eo re sent e d in the material at hand and there is not reason for assuming- t at the largest valves are no'' "^■■It . ?he cl'-aracters, including those of the hinge, are const.scit throxK:-h all the stages of growth. The largest valve has the following dimensions: length, 10 mm.; - 4!^ 6 - alt., 7 mm.; cTiaa., 2.5 nun.: The shell is heav;- ror itc cize ancl the hinge has the charactc '..yen in the diag-nocic of the Occurrence.- Lo~cr I!io:?ene : 'o.vden beds, "^owden, Jamaica f'Jall, 1^"'.'"\ - 137 - Superfamily V 2 II :: ?. A 0 1 A . ?arail3; ^^eneridae. Subfainily Meretricinae . Ceutvs TH.v^SEITELIA Dall. TRAIISEIIITELIA .U^aiOlIDLA n. r^ . gglloearrlia so, indet. Dall, 1905, Trans, ./aj-r"-' ■- "^i^ '^ t.-,.-^, 'Jci., Philadelphia, vol. 3, ' . ', p. 1261 ( e:: pax'te). Desoriptl--.- Shell srall, v;ell-ir "^" '-" \ slightl^ i.,.;.^ i- lateral, roiinded sii'iDtrian'jular to h'roadly ovate; anterior and pos- terior dorsal Ins t;:picallv subequal, posterior longer and sli.flitli conve?^, '^"■-■-' anterior straight; urAones i:noderately prosogTrate, subcentral in posit' ile long, poorl;: dc "■ . " ; external surface sculp ttared with irro " ' lisposed concentric rng- T.e , ^^sually weafe ' "'' often absent Ojj -■,;6t or all of the siirface hut ;n present continuoiAS ac. " vie; hinge •.veil ■''eveloped, the middle left cardinal ohscm'el;" hifid or entire; ' nal tangential grooves pborl; '"'"'-■:''. Dir-i ens ions.- length, ,7,5 Liia. ; alt., 7 nm. ; semidiam., 2 imri. ?.eniarhs.- The raenihers of this species displaj' a r^.e-r\' of variahi] ■ ' ,; . '"V' -^^-ical foiTa, f roni 7i\ich the clLigi^oyi. dravim, is rounded suhtri angular v/ith soihenual dorsal mar ' , mod- - 4?8 - eratel; tv.-isted lua'Dones anr'' -• -"- sciilp'^-'U-e ; ■'■'■' ly small, are more roit.defl, more inequilate-' uj , •rith both the '. n 2 conv e"-: f.nd. r r""'!;" in'''o the l^tersl ".eveloped over the entire shell. " "Ispla: ating opaque and siiht " -^f y'r- - iu^ .vir'.th. This and the £ '"''•" e "^onn,"" of '^sl^oc ' . , ever, rr.t^. ^t n'.ir.- -enellas tie! gTOov the left -.i''''^.le ei ■ " ■ or.t ohscTTc'. ' -e. '^. arri- -loiidea is lesc el ■ ^ - - -^ Transerinella. ooth fotsil .n?. recent, and is Qlir?"htly lar,f from the JpToer Olifoeone faiLVits ol rig?nrreno^.~ Lower Miocene : , ^ov/den, Jar.iaica f^all, lOCP). /IJQ _ THAI^SEKITSLIlA. i:iE'i;HUoA n. . dc-llojarU ., DeII, lOC:, _ . , i last. 3?i., ^ ilacLrlphla, vol. , . , . Jl ( t;: ^arte ) . equilateral, ell-inflatecl ; iiirCc: ■,.... ezteriial bitriace Boulxatiu'e" v/ith fine, alosel, the rai'idle left cardinal o'osoiirel^- bifid; marginal ' ' lal 2-rooyes long but usimllj' v/ell-d.' f i-oe d. f)i-:snsio::£.- .u..-^ 1., . ' . .; " ., . ' .; semi'liam., 2.5 ram. R:- •': .- -':. -:. _f tM- ovate outl' " \ , ' , eon centric s cia 1 "ot nr e . '"line i? Pli^~' " : elonj-atec _ r - ---^ -^-re fixaer - ' . ' - it., -_url, _.-.,^ ,-.,-,,. ^ variants of ahn-on '1^ a . I. ' " ooves are rr.ore ^rononnced than in the preoee \ ,, _ Oocx^rrei-oe.- lower Miocene : , Bavden, Jsiiaica. - ^clO- Gei- 1 . .LA Lirlc. ri"":LA JAIvlAIOxil-'oIS Dall. TiV'. 2a JariiaJQensis -^all. 190-, Trans. Wagiier 7ree Ir^st. oci., PhiladelT^hia, vol. ^, ot. 6, pp. 1^^44-12^.- 5, pi. nv, D-scription.- "Shell aciall, thin, plninp, smooth, or faint- ly coneentrieally striate'"''; o _ .esrly opr.tral, lor. ^l^jc-i, '; :::ia; luniile large, lanceolate, snooth, defined oy an impressed line; n^-mphs short and elevated, dorsal slop.:., '•g'l'Lt, ends "bliXitlv roimded, hase slifrhtl^? arcuate; hir. licate T7ith three small cardinals and a rather long, slender, c ' left lateral; margins thin, smooth; pallial siniis 3r:iall, , Length 6.0, he Igl' t "^ . " , di amot e r 4 . •; r.^ . " "This, the onli,- fossil I'ivela ;y^et obtained in '" vtlantic Tertiaries, is small and delicate, belonging to the g. .'S _2. trip'ori. ell.a 7-?,''^^ "-•''''< (l) a--,. _. 8^sconis D?ll ■ '^ ) "•" +''■■'"■ ""'"^^ent fauna." (o^all, 190S). (1). 11- il2£. looalit:;.- Bowden, Jaraai-a. Hernr>s., Tl^.c collections at ._ ve not xuri' u.c.icional representatives of this speeief: from a single valve. anj- ribed Occurrence.- Tower Miocene : Bow den beds, Bo'^'den, Jamaica (Dall, 1903). /\ /] <-' Genus GAPHAHIU:. Bolt en. SuTDgenus Gafrar-i_m z, 2, Section Gopldia J.:i. aclui::^. GAJRARIUIvi (GCUIDIA) IITOUIAl^S Ball and Simpt.- . Oii-oe (Goiilriiajinsiilare Ball and Sinipson, 1901, Bull. U. S. S'ish Oomm., vol. 20, ot. 1, p. 437, pi. "5, f i^ . ?. Gafrari^ ' ; ildia) insiilsre Dall and Sir-ipson, Dall, IJUS, Trans. 'iVagner Free Inst. Sol., Philadelphia, vol. ", pt . G, -o. 1248. Desex-jption.- "Shell small, j^ello^A^ish white, quite ineqai- Igteral, moderately oonve-", vith £i prominent, ratiT^r a-fiterior bealc; sculpture of small, olose-set, ouhequal, concentric luidula- tions, v/ith narro?rer interspaces and less pronounced on the iimhones, crossed hy fivip ^'r^^x:^! r;-f:-,-iMe, '"hich are stronger frov:,-. v<-ts the ends of the valves, v/here uhe inter 3'^aces sometimes hecoiae tiireaclliTce ; lunule snail, sharply; a.efined, rather Ion:].: and narrow; escutcheon ahsent;' '■■'-''■''' '.ov ' , " i 'a many speG\ ■-■■->'^ --ith a fine sulcus parallel to it arou.d the siiell; hinge 1; palllal line entire hut sli?rhtly trujicete hehind." "Length 5.5; hei^'-'- ; ' ^' Z u..... ' i ^..11 ...... -impson, 1001) T^'pe localities.- ... .. Juan and llayaguez harbors, Porto ?dco. nemsxks.- -'.li^ ,:.....ll species is eirtr, Tlific. A typical adr^ ■- '^'•^ell '-'as the following dimensiOii. : ~ i-"'"h 5.2 nm. ; alt., 5.5 mm.; diam, , 3.5 mm. The adiilt vr "^ x-oad- ly ovate, moderately inequilateral and. v/e 11- inflate , ile the ^. -;l..i^- are more orbieiilar and therefore less inequilateral and usu- ally have a poorly define d limule. A considerahle rarige of convex- ity is noticeahle, esoecially among yoir-g valves, the most con- vex valves having at the same tine higher umhones e ' lighter "linge. The sharpness of the sculpture is also siihject to variation. Invariably the radials are more pronouncecl toward either end. The limiile is sculptured like the rest of the siirfa^e, h'--^ -ith the sculpture v^ea.-rer. L'all (1) iiss remarked that when compared vath recent speci- (1). loc. Git., 1905. mens ^^on ohf ■./hole, the fossils are a littlu : od and asually more produced in front, hut these features are inconstant." -his L-mecies is cha.racterised hy its small siz-e, "broadly ovate o;it- line and strong, fine, i-egular sculpture. Gahh's OuaL'a Hican ""lio- eene "Pse"ohi3 " caij-cellata (2) is less routed ed and less convex. 'r). Jour. Acad. iiat. Jci., i?hiladeloMa, ' ., vol. 37?^, pi. 47, fig. 74, 1881. - 114 - Oe...-re::ce.>- lower Miocene : 3owden ^eds, lowden, Jamaica (Dan. 190;^). Recent: San Juan anr] Mayao-uez hpr^orr:, -.rto ^ico in 30 fathoms fiJall and Si -,.-o_.:^ 19C1). Seotion Hyphantosoma Dall. PITAIHA (HYPH;. .;a) 0A?.3A3;:A (Gupp-^ 0:- the re a (^I'-'ee) carbaeea &upp2\ 1866, '"iiart. Jo . "eol. 3og. london, vol. 22, p. 292, pi. 18, fio-. 1,5. Galljr^ta carTpasea (Gu-opy) Gabli, IS?"^, Trans. ,_ . iios. 3oc., ne\r or., vol. 15, p. 250. Oytherea oarbasea Guppy, 1874, Geol. Mag., decad , 'ol. 1, p. 442 f cheok list) . -jyfcl-crea csroasea Puppy. 187G, Quart. Jour. Geol. 3oe, london, vol. 52, p. 551. Pitarla (E-phar tosoma) carbasea (Guppy) Dall, I'^r^,^ ?rans. v;so--ir.T" Jrce Inst. Jci., Philadelphia, vol. Z, . G, p. 12„G. ritarla ( rlyphantosoma) n. sp. Toula, IOCS, Jahrb. K.-K. geol. Pitar centa^i-rnlata Grown, and Pilsbr: , 1911, "^ur. Aci-.d. Tat. 3ci., : elphia, vol. 63, pp. .'^G9-27"'. 'Description.- "Shell roiUided, rath- llateral, tumid, ulcated "by lines of growth deciissati-: 'iatin^r striae, which divaricate on the cLiccri ' " ' , scome sulDrnp-ose - ■ " n • 1: .oarcely 'distinct; ■ ir /ar-in - ^^6 - ■ .-, ^ '.yoe locality .-' Jamaica. Shell of raedi , , _ iiifla' , , morl- erate''" 'equilateral; broadly ron '""'' ■-■•'---;•—■'- ^ •- ■— -_ ated and more sharply rooi.deii gjiteriorly; hase i lly arc- uate; aiitero-clorsal raarf-in eiccayaterl, ronjacTirjg ahr , ':o the lateral marrrin, v.'hich is s^'^-^''- -■' ■• ^"' - ' rdially; ■:'■", ■o^rrongly prosogyrate ; limiile larre, the bo ' ■ line feebly '. - iJised, but stronger tov/ard the "largin; e":ternal F.-rr"a'^e scxilp- ■'■ closely: spaced, somevhet irregularly ; ,/aally developed concentric Vi'rinlclos, V7eak on the Tne''''ian : :<£ the shell, crossed anteriorly and posteriorly by nuj^ierous id rad- ial lines, VThiol- ^ ~t. - -,j- ,-,. ..j. . ..^^ from either -■■ "" ' ■ aher £".'" ricate to fonn a zigzag sculpture wit?i rasjiy angles; luji- 'j^ c a::" "\,:ho vathout rr'^ial scul^titure; hin^e strong-. -:.::;enaions.- Len^'C:. , !o9." inm. ; alt., 32.5 ram.; :::i-iar;:., 12.5 mm. -lernarhs.- '^his C'^.riouGly scu.lptured c^^cc'-', - ente"'' by a rip-ht val "at is considerably larr ly known s-oecimens from Bowden. It is instantly recognize!', by i'^'S t' 1 , ■ " ■ riated shell and relativel; .; sifi'sog i^tlpture. i" .vO !2c ■ c:ciniens are " " " " ■ '■ric sculpture, ' ' '"ial f are the ^\-.Q :at:" "-'■■ ■■ ■■"^■'lly aratel. -" ^i^ntanc-u] a^c- . ly - 147 - specimen, '^o ..iJi- i-emov - " '- . I ' ' - ... SGUlp- tiijTe, "but i-S sli.-b-'-l;/ less elonc ■*Tor'te'"''ior roil. ec. es-i-ina _ca:e3e.at, b e cj o:;ii n^: oo^c„e';e co".7i:r;-- -■L'^j^'-; external surface sculptTU-er! with concentric rno-ae, usually crowd- ed toward the margins; hinge strong, the left anterior lateral stroiig and promineiTG , the. right posterior cardinal bifid; pallial sinus deep and broad. Dlraensions.- lenght, 51 nm. ; alt,, 70,5 ram.; semidiam., 10.5 mm. ""-ccs-rks.- ?. planivieta is one of the most abundant of the Veneri^.ae. ■^-'■:^.'^"t for the ur^^-al variation in the width of the concentric rugae and an occasional irregularity in their arrange- aent, the characters are quite unifom. It is characterized by its relatively lai---ft r-ise, height and strong, r ef " "i .'^' '% concen- tric sculpture. A closel;. related amdescribed form 0GCu.rs in the Iniplin fauna. P. c-^ra "Brown e.v^. "Pilsbr" (l ) "rora the untu-,- beris, is sraallcr, less elongated ( soae of the s leciraens are i.rve elongated (1). Proc. Acad. _'>t. ^^ci., ^>t "^ >-■ Delphi c, ::.!. V, . ■/", pi. 20, fig. 3, 1911. than the one figured), with slightl. " rect uni- bones and finer sculntujce. Crabb ' s Oosta '\ican Pliocene P. gup- A^-] _ pyana (l) is smaller, "less ir '"" ate ral, ■ more inxla'- " , Ith a larger and more sharply limited lunule. P. oir , ' .orzi) (2) (1). Jour. Aoad . J-^at. 3ci., Philadel'Dhia, 2nd ser., vol. n^ --p. ?7^-?74, pi. 47, fig;.. 75 (as Jarrratis -up^yenal (2), Ivlus. Oaes. Yind. lest., p. :i, pi. 4, fig. 8, 1780 (as Yeniis Gir^inata) =C):;therea jiTncea Crup -.y, Cuar''. ""-Tir. ■?eol. 3oc. lonrlon, vol. 22, fi-'S. 15^, 1866. ranging from the Oligocene to the ?.ecent in the OarilD-oean and Oentral Anierioan regions is smallc r, more roiindcd, hi^-hcr, more convex, v/ith more prominent umhories and fjoriev.'hat lamellose acr-lp- t -re. It Y/ould he virtually inipossilDle to disting ' etv;een ~orn valves of 'ilanivieta and those of ^'acrocallista macr.lata {Iin::a:as) (S). (7). 3y?^t. ''at., e^. 10, --i. SOS, 1753 fas Venns macnlata) . Guppy (4) noted that his figured s;ieci- en is slightly dis- torted; the in'oho shmTl-"' he more inerrved, the posterior n more (1). '.--:. ''\':., 1876. rounded, the posterior carina closer to the YerA: " in and the shell in general more inflated. Occurrence.- ';per Oligocene: to Domii. aVo , IB??; A, '^■ aupr^y, 1876; DalT, 1907); ?;hite ^^each, iie^; re^, Florida ^Dall, 1903); lower Hi ocene : "".o^aen "be : , .-;den, Jamaica fGuppy. 18 C-, : ,7-.; _-.ai, 1902). - ^-^7 - Gen^ " 0^'A Sehfunacher. .11 ij.i. ' unci ;• . Cj • Section Vent ricola. ai:tigoi:a (YL::r?jGCiA) BiAiiDiiiiiA Cgupp^-.j Tenus Slano 1^::-., "^^^:7. "^ """ \ ^c-" . "^:: . , , ---1. 1, p. 1?6, -;1. 17, fir. 8;;p. 442 (cheek list), '"enus Blandiaiia Guppy, 1876, '^kiart. Jour. Heol. Soc. London,, vol. O^^t'ierea (Veiitrioola) 31andiana ((Juppv) Hall, 1?05, Trans. ' :■ .Inst. Sci., Philadelphia, vol. 5, pt . , p. 1277. Sescripticn.- "Suhorhicular, suheoiiilateral, iv^Terately con- vex, adorned vrith numerous equir'i^t?.nt '?oncr>r.+'-':-io In'^el'^ae, hotv:ce2i each of which ' are vbo.-i; t even or e ' • '-■ z-triae ; somewhat ai: " - iri fro ' ^ " .e ate ■ • ^^ins cren- ate. lamrile smooth, i . " . '^ : ' "■ ~ ■■ '; '^efi-io'-'' , ■ itriate continuously' with the iaijiel"' the disk. "mhones .-.:.:all, Cardinal teeth ttvo Ux/Ier the lunula; lateral tooth one, v''^ ..alfway do-m the poster-" nv r-Tope." (--u^''^'', 1874). I^^^pe locality.- 3:_-i'Go -'oriiii; . Shell moderately' larre, ovate, al , well inflated; ant ero-dorsf.l r.iarc-in shor , " ijrhtly ez.javated, roiuidin^- ^. r 1. abruptly- • into ~ ^ ■..-,-, ^,,.\. ^ ostero-dorsal terio " , - . ^ . T ..„, - -1 t e cbiinentrio sciilptiire ; escutcheon flattc , "" " b- a -•ea': ce.rl'ia, fee'bl;' rtriete^; exter; v.l ' ' romi- Gheou, terniinati ' ^ - . ■ • ,^.£ ^^^g escutcheon and limuJe , I'jvL" iinixn?'' across them as stT'^a.ti ''n Qr-fT-rsv^ "■"h; .^" i.,'.j ^uit^ L-.^^ ji.. •r.i'bo, lo.'^i.-, ■'.amellae intercalated "oet-veen the ' ry ones; hin~e 1, the right ;ni 'die and -'ior cardinals h'fi'-'', the -^oe ' " -^svy and ^,\'- "-■'■-- --•-:- j::c jb;-wj.-i^; ':'ac left middle o ■: ' ' " " larro; in- ner nar.;rin of the valve mini^'t el;- cr emulated. DimenFiion^ .- length, 41- . 5 ''in.; alt., "^V i .; ' irn., 15 mm. ^emarhs.- '" " ox this species . ' -tel;,' r^lB- '*"~"ishcr' ■^''-0'^ t eoncevitric sculT^tiTre of t"iVo oi- " '. ':ude. jl' ' '~ c more •elongated than yojmg ones, ilrrB-r;, 11-^ e .;ore thiclcened and fe7.'er so ' '.cli.'-' .lirgins. Cn the 1& ' " ells, ' '9 ridge, at v.: ..•imar;, 12a e ^ * .'isihle ■^ rihort •-■! i ;- -^ron the :'' " '__ ■; escutcheon, the t ,.- '.'D.ien er ? o ox X t _ A- i ■rhtl:; t"0 oiUicea eno -L.rj'.n to "be atig-litly insirraater'. Drll fS), of the recent ".7eat Ii;diaii fauija, A' _^ ■■•.1^ ■ "oriniar^ corx- fl). !.:>-. .. ^ oentrio la.riellae, lower an'^ more r.^re clistlnot. -• -lo- - 4- J- i.'j-' SGxilptvre Ooourrenoe .- 'ig-ooene; . ^-o Doninro (G-iip-)^", 137-1 ;i67t; usll f IdZS); .I'liitc Beach ne ': " ' -?^<^^ » ' . i^^ll, IDC"); Jhip- ola marl, 71orida (Dall, IOl'); Ouracao{ j>iall, 1905); Lower r.io- cene: ^av."!. en he els, 3owder. , . aica (Guppy, 1974; Dall, 1907'-). - 'Lse - Su"bfa ■ '' xi c r i n ;: u. -iLLA Dall. OYOlIlJpiLLA PIuiSIATEEUia n. >ry, DescrL^-- '. ■ , ,„- Jhell ^^ "'■ .iae, ';': I'l, ^^ ■■■biGuler, sub equilateral, moderately iirifalted; dors-" 1_~ j_^i "f; Q ■f"'!^5 "'?'t'^r°T. r'' '-! r '^"1 n P * f^l i~"'^'t;l'^" i"~T'g> nvoduc "^ sriorlv* eixternal surface soixLptiu-ed with unennall; , ''iue con- eeu':"-'ic stride, more nrononjioe'^ on worn surface:; rnal, the tee'' " -iie:'!^ ^j j.^-reiiut; ~ . Dimensions.-. Lat., 24 mm.; alt., 24 mm.; ' ' '- •, 3 liici. Hemarlrs.- 0_. plasiatenuis is >nor,'n from rr. incom-olete left valve. Onl^/ a pax't of the I'liixule it; ^^retjervy ., uub i ^ i-a^. be ^' dged that it is relatively Harge and limited hy a feebly in- cirec! line. 2his species closel;' resembles ''"' '' enui s (H^cliiz) il) of '"' ''-i size, but is more orbi": ' ' "''"•- 'vith slightly more eom^^^ressed teeth. J. oyolioa (Guppy) (?), from ^1). Journ. --le Oonchyl., vol. Z- , p. 2 50, pi. lo, :^1 ;.:. 1, 1', 1 as Dosinia (Artemis ) tenuis. (?). Quart. J-)",r. G-eol. Soe. I'. , ". ''"^', p. 502. f:r p. Eocene of I'anzanilla, Trinidad .twa 0. ';^atuacngis _ '^.^7 — Dall fl) are lar^-er and cteeidedl;,- less or"biGii7_" r. fl). Trans, r/agner JPree Inst. Sci., Philarleliohia, vol. 5, ot. C, p. 1285, pi. 52, fig. 18, 190:^. ■jc^scroiioe .- Lov;er Ilioceiie: Bov-lezi oecls, '-i-, '^aiaaisa. 458 Genus GHIOIIE I.legerle von LItllilfeld. Subgenus Oliione 'i'. ?. Section Ohione s.s. OHIO::^ 3A^KIi:3I n. s;-). Venus ".7oodv;arrli Guppy, 1866, Quart. Jour. Geol. See. London, vol. Venus V/oodv/'ardi 5uppy, 1874, 3-eol. i-^ag., dee , vol. 1, p. 442 ( check list) 67- parte, "ot Venus V/ood^vardi '^ur)p;- , 187g, luart. Jour. Geol. 3oc. London, vol. ?;2, p. 550 (= a. gu.ppyana Qabb, 1875 K Chi one Voodwardi f'^^up^y) Dall, 190?^ Trans . :'r ?ree Inst. 3ci., Philadelphia, vol. 5, pt. :, . ^ '^^1-1292, ( ey parte) . Description.- Shell of :i\c ^'^ ' -'''■'. sizu, ^(^'. triangular, moderately" ineciuilsteral, well inflated; produced and broadly ro^■lnded anteriorly, lor/er portion of poster i '-in oblicuely tr\jnc' ted; lurnile crossed by imec[uallLy developed lamellar contin- uations of the conceiitrie ribs; escutcheon relati'ely narrar, striated, boi^ndc-S by a rounded carina, on the left vslve the mar- l,lu adjacent to the "" ' '""ix-l tv:o- thirds of its length; a short distance from this carina a sec- 1 - r: ■ ';v/eeii the ' .-.'inae vSliglitl^ t tho margin t"he truncation; e ternal ' iii-- o\:a aonceii ■"■ , '" '">" --^f the shell h ;vi.. ir e's*-^ tuiokeael and turned bov/ard tlie ai;ib9, e::cept near the liuiule, rlth, on their ventral , ils, oep;- ■:-ic.L-:icb aoes hut alt t- less •'■;ell radials on the shorter ' :. de o:" is; along a ■.-^.i^-r.l li;-'- "i,:.ri i" ■!:" :,-^ r^^.ln-|^ of the Shell '"~ - ■ '■■• T'i'!^'^ ■; -•-: • ?rd t" oral laargin and finely; ^ 'l;,.' arenulat- cd, from ti-e en"', a o:'' each erentilation iiarrov;, ' ials exten'''.ing aero'. . " - • i ? .> -^ •-■ . ■ • -q nor--.?!, tlie 1' rdiiial strong aaid the left ee cardinal ohscurel, DiTiensions.- "■;■ '"' , ^"".' ' ''. ; '•, ■ •; '^iar:;., 8 rjm. ^iemar>3.~ Tith regjard to numerical re pi species almost riv?1 s 'J, f Liroph or a ) he"' ^ ^v '^ onx , b^^'' '"' ■ .-•''■-o-^-_ sc'^'ers are more constant. Ihe nuraher of ribs oi .1 tei'^ milliraeters of the shell -^s from - - shells are more roinded in O'^'""" ' ' _ ' .. '\ ' ■""'"' — ii. • crenulate'' over th 11. £, sa^kinsi i ized h;^ '" ' 1 Titerior trun- -■;*■-•- " " ifference in '■''■- --■'■■■■• "^^'^■^' "'■'' - 46r. _ Guppy's two ■ £. Y;oQn.A.£irdi -PI .-, •- -J. C iJ, ' J. J- i t i C. £, v-clli fl) from the 3ocene of i-'pnzp-.iilla, \;lui-''' (":]; it i; i:, 1866 fas VenxTS Valli). (2). .,.■, :,1 (luu. .;it., V "''^1, 190S) c' ov/; it does not e in an^' of ' -lie c Lions. less ineciuilatersl , more prodiic ':eTioTlj , narrower l^nv.le - ' 'f"''^G re'"^. t p CT-l''oti''re the cor centric ^''^TiW— lated.t": \uub aiiu ovex- the anteriur ^a^.d ue .i»-ti vcucircl poruiono of the shell the radials are in pairs and the c of the concentric ri fine and iiot int ermpted hy ':' 'iT^S' of- fer (Uu^ the rihs into pairs. ..' Jirolin. [5. g rioraria {doi: {7.) ia f;:). i?roG. Acad. i'at. Sci., Philadelphia, vol. 1, p. 51C, 1045; ?os. Med. Ter. U. 3., p. 67, pi. .'^8, fi£. 2, 1845. - -ch lar'^e • " j"" '" '\ the ^'O'A:-:^' are q'^ite . ' '"ar in : cneral j^earance to the arValt ssv:>;insi cince the t7;pe ' jtnre is ':\e ss^ne, thej" ms.^ ' '^s ti nf-n r he i^. "bx their , :noro gently: rounded anterior ' , ' iTier " ' escutcheon J - IGl - loijger and more rcflexcd e'^.[:QS on trio concen-^ric ri"b3 aiicl the is ^iven in' ' ■. James . ' . who o ■ sueoeedecl llr, Barrett as "Oireetor of the earl;= J-^^naican Siirve^'. Oecr-rrence .- Lo^'er Miocene: 3 he-s, BowcLcn, 'Jamaica (Guppy, 1866, 1874; Dall, 1907). ghioi::j Z^TUGIM n. s-n.' Description.- Shell snBll, moderately inflated, decidedly inecaiilateral, eloi'i^^ate-ovate ; posterior ma r^-"''. lor;-'', alnost strair^ht, slopin „'-ii'-"ly, anterior end roimding into tuc- ; ij.:'.L;e out slightlj' curved in its median portion and at the posterior end turning up abruptly, meeting the T)Osterior marrrin at a Ghez"p angle; tlie Incised line "boiindirjg the linnile fee'oly i;:'pre:jsed; escutcheon long and hroad for the size of the shell, the proximal half of its msrp-in adjacent to the liti-ar-iont slip-htly raised; in front of the suorounded cerina, li itii^^'- the escutcheon, the sur- face of the shell slishtly depressed t o.v ard the ventral margin, 'hut not enou!^h to affect the 'T?rgin; external s^'irfoco sculptured 'Afith a moderate numher of concentr' ' '.os v.ltn prominent, round- ed radials crossing the interspaces; near the luaiule the edge of the concentric rihs turned t or/ard the ven-'-ral mergin and vreal'l-:: crenulatG"^, out over the remainder ' '"he aiiterior tv;o-vhira^ of the shell the e dp^e tiirned •' 1 the umbo, thickened and the crenulati o::s feehle or ahsent; on the -posterior third, the e'lge is again refle:-:e";, lengthened and c renulato". ; weal: continuations of the rihs present on the lunula; escu.toheon striate' hy the fine, concentric li""rn o'-'nr.r-i"-- th? radial; ; ' " ~s noi':ial, the right anterior cardinal" " ' the posterior comxjressecl. Diu^i^oi^ic,.- ' ■.; nl/-.. " ." s-.- --ri.(llyui. . 1. > J mm. -^.emai'ks.- A nuralDer of yr:Ell 'of this species, most of them heiia^- la. rger than th , ■"nnt s one what v;orn, th^ i- --'.-■<: v..,.: , -^'hese d i u- ' : Itii^th 9.8 r:2n., alt., 7 mm.; seniiaiam., C.l mra. The co: ic sculptin-e is of the t;y-:pe th^t is well-exeraplif iecT hy 2» s. i and, as in that species, un ofibII valves the rlhs are crennlatecT throug-h- out, v;hile on larger ones they are thickened and smooth over most of the aiiterior two-thirds. I^ine to eleven rihs a j.'e present on tho' ■/-- '■ ■." five millimeters of larger shells, hut on small valves this nizmher maj? he increased to fourteen. The snail size, long, -almost straight ^octerior ra rgin, P^yc-'■•- --teri^r turning up of fche ventr;iL ::iaigin ' i-ll-defined radials that crenulate the posterior -part of the concentric ribs, are diagnostic feat'^res of 0. retugida. It is -orobahlY a dimJnu- tive offshoot ox the stock v/aich produced gup";:i, from the young valves of which it differs hy being more elongated, with a long- er and straighter posterior dorsal margin .: ire distinct rad- ials. Occurrence .- lov/er Miocene : Bowden beds, Bov/den, Jam.aica. A. _ JIIIC- .d.JAdDl (Gupp;;). Venus V'ooclwardi ""upp:,", 1866, r*uart. Jour. Geol. Soc. london, vol. Teniis '.7oodr;ardi ."uppi, 1oy4, Geol. Hag., decade 2, vol. 1, p. 442 (eheok list). «* f'"^'' "ot Yeiius 7oodT7ardl Guppy, 1875, '^iiart. Jo-iir. Geol. Soc, london, vol. 5E, p. 550. (=0_. gupp;>^ana vaoo. 187S), Gliione ".Voo d?;- rdi (Giippy) -"all, 1905, Trans. 'Vagner ?ree Inst. ?ci., Philadelphia, vol. r:, pt. :, _. : £31-1^3." .C«^ f'^'^''^ «--^^-^.^t * ta^x^ ^ <•!; . ; sua .^ -.- ■ '^. ■i^'^ t-^-, , nrnl;lpr" - ':.-:.fi^ rounded trigoiial in outline, the anterior maxgin roiu.ding evenly" into the :/jrt base; the hase on t;;; pica 1 adult shells slightl;- insinuated near its posteri-r '-•■'', ''''''■ ■-^o^ '-■■-■->•' -■_i-ii slightl^' ciu''ved; umhones places well to'ward the aiiterior end; lunule larre, orna- mented, hy continuations of the eoneentric rihp; escutcheon striated, li:.dted "by a sharp -^p^'V'ia; sonie cTictance in front of the posterior iiiargin on the ventral j)orti"on of the shell a poorlj^ -■''o- finer", sli , '"^""f" i'^ref^'--''^ 2rly crenulated, i:.::iediatel;^ hehind the Imixile both racli&ls and the interspaces se];^rati)Tg them relatively broad, to-rrard the center of the shell the radials re- taining their -^ -ir? '■>i n-,- pl i" rr>,tT T- -.lo-,— 'nr-r-i-^ "J-.-i-f: -'r.V n interSpaCCS beo ming narrbvv:e.r, as the esciitcheon is approached the radials rapidly becoming narrower, typically the concentric ribs ceasing abrr.^tly --^ ■''-'-• '^-■-•"■^ ■-<■: bounding ■"''^ e escutcheon; hinge normal, the right ariterior eardiual interiial al crenrJations relatively coarse, Dinensiong,- Lciigth, 21 mm.; alt., 19.6 rm. ; semicliam., 7 nm. Hemaric£.- The rather numerous valves of this species line. The ventral ly situatecl p- or depressed area aiid accom- panying emargination 0 f the ventral Ria.ro-in in never conspicuous on young shells is ^^p^'-it^ the ; -; '^^^ more -'--•-.-i- " -^^n "."'•^Its. There is also sorne variation in the proportion of length to h...l.ht. One of tv70 of the broad anterior radials nay be med- ially sulcate'-''. Occasionally the coneen-^ric ribs, '-''■■ ^^- -"■^ r^.n-.- - 4-65 - reduced., f re present on t e x^osterior carina and waj' pyen con- tinue for a short distance on the escutcheon. On the ■'.'■ontrrJI ten Tr.illinieters of adult shells seven or ei£"ht cone er trie vi'br. are present. Tlie -^ - — Ive u.-. the follov/ing- diix-iiuioiKi: leng-th, 25.5 nn. , al"-'- . , 22. .; ser/ ' ., ." mm* The charactf-^-'isti c ,' j'es of C_. £di_are its height, large Ir, "-"'' ^ ' ' he concentric riuti are oontinuoT"" strong radials that conspieuouslj crenulate the relatively fev/ concentric rihs. _;_. \1_ never ref ':he size o-^ the recent canoe Hat a (Linnaeus) ( 1) , which ra:.i^"es to liuc^snc -^ijl iti riore conve:-;, hi^" " h hi^hi/r, i^-i^e nuraerouB _ ore sharply chis- fl^. Syst. rat., - . " : , p. 1150, : ; -cove, Joneh. j-con., vol. 11, pl.'lv', ■ - ^, 1S63. eled radials and oori-espondingly , more numer- ous and shorter, hiit more deoidedlj' c - , centric rih^'. ■^".:f;rar-" to ^upp;, ' : ■ ■ • ■ • ^^ foxm ■vhich apparently v/e. j as 0. f;-'a.]r^-:;&na (2) .is distinct, heini^ lar , e ron , ' -ro^'er, lov.'er rarlialr?, (:}. Trans. .Irn. Philos. 3oc., -, "• ^ \ p. ^'\ 1^':'^. "er radial interr-:' , less Ir. '" concentric r'^ -^e linea- ' ir ven'-ral . ' ' th ^',, so::'.- vr,''-- -- -■•'>-^ lirie Cu-. ' ata 'ih'-'n "" ■."0 0'^-"-"rdi . - ".67 - "^^attu. 2» — iliilll.'^: ducei" -jriorl^', i^ore inflate '1, (1) ■ to v.'oorlr'crdi -"■1 a ve- ; it is le.'::^: '■■■-■ rower u: (1). ?roc. - , ■ ,. . .:u:... ^^-^ -'-♦■■» • » X Jl... :l:lal• the shell more i ' , 1- riorl^? aud the posterior ventral ". ' 3inuated; hut Qceurrenge. - Up'"- e r 01 i °'0 oen. e : I.orer I/Iiocene: , 1^71-; I'all, 1905). s elite d. - r' : \ . r- X' , - 4-68 - 3eotion lirophora Oorirad. OnlOi-jJi ( a, J. . . ^ .-->... j^J30i:iI Dall Yen 113 paphia C W'O he , , -'t. t; : * :1. ojc. Loud.on, vol. r.2, J... .- , inon LinnaetiR, 1""^^. > ' ■ - 'ps."p''''is. Mw-Oo, Ic , . ii-vi. X' 15, p. - ). 7enu^ -„ ... ^, , _ ., . - .., -^^^e 2, vol. 1, p. 442 oOQ., riev; ser., vol. ( Jiieo-; liL 76 , ii. Yejius papilla 't. Jour. Gtol. oo^;. Loa-lOii, vol. "2, p. "^i.O (nori liiina'^yO Qhione (Li:oop"'-?ra) Hendv rsoiiii Dall, 19C' , . ans. "Jagner ?ree Ir^. t. Sci., PMlaaelpliia, vol. , . , . ' ;95-1296, 1. -5, fi- r- rr J?- „ o o De se ri -ot i^ii •- "Shell r eB(=^r>bl ija" ". , 'but v/ith abo '" ""^"fteeri the ra-isl sculpturce rese:- ■ i e s _0 , "ballista al leases -" '" " -Ti v/hich are rarelj' di er , some ti rue s o-q s cur i: which the tliiek ril; off the posterior thi ies iioted; the foliati rieB of pimctuatioiiL) into striae; the rihs are closer toneth- -■ -•.->-,■,- ^ ,^ . ^ imagiiiarj- line -'■*- _1^' ue 'er;,' thin said elevate" : s?iell , -OL' e ':':arL in anj" other c_i.:;j- ,re very tliin and vrcrs '.reseuraahle ele- - 469 - vated, but are destroj-ed in all the specimens e::cmiine'''. In ■harraonj,- "/ith •tl- _ _ , ': '^f the nenl -ot -re the posterior e-nd of the shell is sc " ; ' ' ; .e liin^ile and escutcheon are T/ider than in 0. ballista; the ' 'i.ial, '^he teeth entire, the pallial sinus small an". , th n ati-Tiictor scars r.^-^hr- n --i. Length of an average £peoi:.an uv.o, nei^^irG iiw'.S, diameter 14. u nm." "The Bov.-de- others ith the recent 0_. :':;'hia b^' -,.., " ' -d. Onl^- a comparisoi. i. ^ needed to prove their distiiietness. " (Dall, lOO?'). T:,-pe lo-'alj-^; .- -.cv". ., Jasiaiea, Shell - ■ um sise, well inflated, ov'"''f-e-t".'igonal; rnargin sharply excavate i. anteriorly,, posteriorly? almost straight; vm- bones high and tumid; lunule sharpl;; define"',, striate-; esciat- G'''''C?n broad, bounded b^' a v^^el 1 - ". e pr * , , ':•'•■ ated; sciilpture of fifteen to tv/enty-ty;o concentric ribs, all ericept those on the tip of the umbo thickened and reflexed; along a radial line about three-fourths of the distance from ^" 'iriorerd, the c'"'-'--? -^^ the ribs suddenly fle3:ed downward and ■>: ' lav er and thinner anfl as such continuir^g to the (K.rina bounciing the escutcheon; ant- erio"'^ly the ribs evaneseing-r.bruptly „ "-'■: ■distance from •f-''^^ in- cised line liputing the lumile, the edge of the ventral riba be- ing, v/hen perfect, geiitly reflexed ; ventral base of the ribs ob- scurely or obviously punctate; between the ribs incrementals present, 'beGOKLii^- more prominent anteriorlj? and oostoriorlj; and striatir;-- the Inraile and eGciitclicon. ■Divcncions.- Len^tli, So. 5 . ui. ; cl':., '^'".5 mm.; semi'Uam., 9 ■ Hemarks.- £. hendersonli i ;■ a proliflo form and at the sane tirae is very varialole, f-e ^ne end of the series ^oeiii{^ ^'lore con- vex and. having higher "urJoones, a steeper posterior slope, r.ir'"e ' excavates '.n and a : liinule and escutcheon ^" the other. Such anti"oodal . te distinct, hnt are con- nected bj/ int ' '. " . ^'he nuj.iber of zihs is another uustahle feature, hnt is nc ' related v/ith the others, either enii pro-r. dMot havijT"'- ypi ativel/ 'f*!^''^ or nr'''T'-TO'-'f -'^ii-.s. The avera.p-e nnnii-\r.r of rios is sixteen to ei"-iiteen. ./hen the interspaces are v/ide, "i; a sequel of the re'^uction in the nunher of rihs, one or two of the iricrenentals in , :.nterspaces near th- " •"■''-in —^ oe emphasized. The rihs are very rarely as closely aopressed as is shovm in Dall's figui^e. xhis species is characterized h; '^-'ther mtmerous ribs and the relatively ^ide poster! -r area over which the ribs are lov/er and sharper. The form mentioned in the original descri o- tion, 0_. ball iota Dall (l), from the -arapa silex be'^^s, has less (1). loc. cit., p. IPO.^., pi. 55, fig. ??:, 190?. numerous, occasionally ventral striate'"'., ribs that are atteni'iat- ed closer to the dorsal margin. The Oak Grove 0. glyptocyia - 4 71 _ Dall (2) resemlDles the less convex iHue, -ji' u i.- liut y. Ic^jl; ex- cavated anterior niarjrin, ribs that are ventrally striated and the (2). loc. Git., p. 1205, pi. ^-, fig. 21, 1903. point of re'^'xiction of the rihs is r^e-rer the esciitcheon. The Pliocene and recf. .t 2.* laphia (linnae-;j) (5) has a similar appeai"- (5). S^'St. Tat., e ■' . 12, p. 1129, 1767; Reeve, 3oBCh. loon., vol. li , Teniis . pi. 19, fig. 89, 18 55 (as Vemis -oaphia) . anee, hi^t reaches a larger size, and has a more arcuate oa^e and more closely aopressed rihs. Qcenrrence .- Upper Oligocene: Janto T)or.iingo (ua-^o, l''>7"; Guppi, 187^., 1876); lower I'iocene : Bo-.7den he 'S, 3owden, ."'anaiea (Gnnio;?, 18£6, 1874; Dall, 1905). _ /l 7.? - Subfamily C- e ra m i n a e ,, Genus PAHilS TAHTE 3 on rad . PAHA3TAHTS A TIL^^ZT^IS n. Oesarj-pti', n«- Shell s'^icll, narrov , ' "i, trip-onal, well- inflated^ siibeoudlateral, -• - - oriorly; snb- truiiCate^ anteriorly- '-eriorl;: , • arc^iate; uribo ver;- liig'li, tumid, sliglitl; ;;rai;e ; ;:. -1 £iii:fa?e scnlptia-e' vd. th increment als and o-oseui'e concentric r' ' , more prominent ventrallj', and a few faint radial lineo on the dorsal half of the shell; lef-u valve v/ith two strc " ' 'It? "bifid cardinals, sepa- rated "by a relatively hroad and. deep soc':et; inner margin of the V si ve f i ne 1 y c r en ul a t e ri . Dii.iensions.- Lat., C.5 : ui. ; sit., ". ,.; semiuiam., l.r, ; P>em.:rl:s.- The oce ^e of a ciii.?-le valve of a Parastarte in the -^owden fauna is surprisi ' :ie has heiv^r heen reported from areas outside of the 'Iz ' ■egion, vhere it is represented by it ,2* triquetra Oom-?/^ (l) V7hich ra;ir;es (1). Proc. Aoad. i:at. Sci., Philadelphia, vol. 3, p. "4, pi. 1, fif 5, 1845 (as Astarte friq^-ietra) ; Proc. Acad. ITat. Sci., ?hi''a- del-ohia, for 18 5.^, p. 2^3, 13 2; ^^all , "^.ull. TJ. 3. Hat. I.: ■ ., no. ^7, p. 48, -ol. 49, fi ^-c. 6-3, 1389. from •'■Itp' "'■ ''1'? ene to the '^eecnt. The ""o'"-"''^!'! "'-"■'•n is vei-y close indeed to triquetra. being slightly more ij.ilatcd, ■ ith itiore - ■1:7'^ - tximlci aiid "oro-j.d.er , " '■ .;lv teminatinj", iitiDones, les:. G renulat i ~ . :- . Occ?;^rr 'n^c- Tov/er .j.iocene : , -, '^aciai^a. - 1:7 4 - ^ainil"' C cop ere Hi 'la. e, 30C-?/--l.LLA Jar-periter. Seeti.^n clla n. Geot, Etrniolo-:-.- ■ ■ , ■ ^ ■; " " , ' of the ^■eneric name . except for o 3 conGeutri. '.ae ; ;' 1 1'al Oooperella. both tlie licarp.ent ez.<^ regiliimi sliorter. 475 3J.IA (]:n.:u2Li^) ']:i:adllista n. .:,• r- I ' ~ ' V quadra '-^e, sube _ " , al'le-O' "la ted; o'.T^adl^' rovjvl'/ eriorly, ©"blicn^elv ftnbtmr.-.n.citerl p" ^7, ^- portion of "base a^ "^'-•^■^ ' ; ' , , ' , tly proBO- ^; ; erbernal sarfcice beari ^ ''e, t "^arly spac- ed c -■ --o; I'^-a': sViort, -'8a short, r." '"■■' "^-tel^ _ ^ _ , ^ largely- exter. " , both place-i' "-^'-i-'r---"^. ■;-■'- ^ •-• cardiyials; left vsl^ s d-^.tIj . d, "' . / ■dinalii, the anterio'o end posterior ociiiressed, the ' - -. ^ tri angalar ■^.^--. ..',■.. ^--/i.t.l„' jxri.. ; ^ 1^.^ . "■ -., ;:-allial line ohsciire . Siiaensi^ng.- l^'Cngth, 7.5 niti. ; ...l^-t., 7. ... .; seminian'.., 3.5 ;:r-. I\e marks,- I'. ' eoiet, "_ .: ' l, "! hj' a siiiglc left valve, is rer:Ta3:"y:able fc . ti^n, the diar.etor almost -—"ling eit^- - ..^ - - ^ ., -... -■ .^ valve ■ • I'lio"!!. ' dial line is obscure its pdsition is doubtf"!. On 0-^ the left va]ve .' : j,^''-'..-ja.l^- ' -: i placed in that . represent- ed 07; 2 single sr)ecies Oooperella siib'-"^" ' . iter) (d), ■'.icQ is ■■-"■ " ' - '" '^aci.^i '. A. other . , ... ..-- _ '17 G - nt.-ri ^all f"). - '^7^1in ITiooo... . ^^o:l these ("). .-. . 3ri^ . _ . ., -r IOC, . Cr^O, 18G^ ir.), '2-rt^ . ex 5^rae Ir_Et. ^ici., Y. ia, vol- 5, ot . 5, p. 106?, pi. 49, ■ - 3, 1?G0. I'l.e Zeiiito iJomiii^'iaii f oi'iii ^i/hieli Caob (lesci^roea e. s Mysia ea^:)- :;loice- (c) :'>robablj' "belongs in the same groaip; it is less qnad- ( r ) . I: - :„i, f hilos . 3oc . , rate and is scr" ' "'^ ''lefinite, 'c striae. Qgg.-ir-T'erL^e .- Lower Iliocene : Bo^rrijen he^'s, Bo'vrden, Janaica, ^77 - Superfanily TEIilUAGEA. 5^ar.ril37 'ell inidae. Genus TELLIITA (Linnaeus) lamarck. Subgenus Aroopagia (Leaoh). Section I.Ierisca Dall. TELIirA (lTERISCA?) ^I^OOOSMIA Dall. Tellina (llerisaa?) acrocosmia -^all, 1900, Trans. iVagner ■''ree Irist. Sci., Philadelpaia, vol. , ot. 5, pp. 10.'-:0-10£l, pi. 46, rig-. 10. Desoript io: .- "Shell sr;;all, i-ounded, triangular, v/ith near- ly- oen '-ral inoonspicuous beaks, and hardly point e'., slirhtly fle::red, posterior end, the anterior eiid evenl;^' rounded, base eon- rer-li' arched; Irjiule obsolete; disk covered v;ith a fine ra-^-ial threading, more or less concealed by fine, elevated, concexitric shariT lamellae; hing-e normal, teeth lar^e and strong. for the size of the shell; pallial sinus larrre, nearly reaching the ant- erior adductor scar, largely co. flue t belov;; above rising above the level of the posterior adductor. Ion. 7, alt. 5.5, diam. 5 nm . " "This very comToact and sharply sculntured little s'nell is very distinct from any of the other local or any American species." (Dall, 1900). Type locality.- Bow den, Jamaica. - ^.78 - Remrlr_s.- Thin n-iecies, v?r. ich is one of the r.os t abiindant of the ■i?ellirjas, i'3 iu.i-.ediately recognized "bi' its smrp sgliIp- ture, sharper than in the average form of the section, ^he radial striae are fine, hat relatively cons-oicnous and thc;^^ finely ■ and sharply crenulate the ed.^^e of the cor:eentric lamellae, except v/hen the lamellae are heavier than usual. The areas be- fore and behind the umbo are flattened, especiall;: on the left valve where the margins are compressed. The aver, ge adiilt is slightly more elongate than the one figured by Dall. Occurrence .- lower Miocene: Bowden beds, Bovvden, Jamaica (Dall, 1900). - 479 - TELLINA (I-CSISOA) 30ISRA Dall. Tell ilia d'eriaoa) solera Dall, 1900, Trans. I'/agner Free Insi:. Soi., Philadelphia, vol. 5, pt . 5, p. 1021; pt . 6, pi. 49, fig. 5. DeaGriptioii.- "Shell minute, short, plump, with lov/ in- flated 'bcar-a, roimded in front and belov;, Ghorter and "oliint he- iiinr- ; sliR-htl^; fle:>:e:l, not rostrate, but with , jolote rad- ia.1 sulcus in the rifrht valve; sculpture of elevated crowde-'' con- centric th-reads, 'beeoniin?? alterrjately obsolete tor/ards the ends of the shell where the persistent threads are more slevated and tend to become lamellose; hinge normal, strong for the size of the shell; oallial sinus short, rouiid, cor;-^1nent below. Lon. 4.2, alt. 3.2, diam. 2 ram." "This libtle shell is not unlike T. acrocosmia Dall, but smB,ller and without the stroiig ra'-^ial sculpture." (Dall, 19 '^0). Tyrx; locality .- "3owden, Jamaica. Heroarks.- The largest of the valves of this species has the following dimensi -^nsi- length, 5.:.- :::....; alt., S.8 mm.; diam. , 1.5 mm. Occurrence . - I ow e r I .C io c e ne : B ow d en beds, B ov/ den. Jama i c a (Dall, 1900). _ AP^ n _ TELLIITA (I'.IERISOA) SOLEI^A var. LEI-i/iSOA n. var. De script ion.- Shell snail, moderately inequilateral, dec- idedly inilated; broadly roLiiided ai.teriorly, olantly pointed be- low and flexed posteriorly; iinibo tiiraid, low, broad, placed near- er t";: c ^Dosterior end; external s^rrface sciTlptiired as in the tyoi- cal bc-lera, but the concentric striae le lss cons :iGa.ou.s -posterior- ly; hinge nomal, heavy. Dimensions.- Leng-th, 5 mm.; alt., 4 mm.; semidiam. , 2 mm. Re mar I: s.- The single loft valve on \vniGh this variety is based stands in decided contrast to the other representatives of the soecies; it is decidedly more inflated, less inequilateral, less elongated, more pointed and more flexed posteriorly, with a broader umbo and hesvier hinge. Occurrence .- lower Mio cene : Bowden beds, Bov/den, «^araaioa. TSIiriTA (MSRISOA) AE-^UI STRIATA Say var. BO'YDEITEIvSIS n. var. Tellina (I-.!erisaa ) aequlGtrlata Dall, 1900, Trans. Wagner ?ree Inst. Sci., Philadelphia, vol. 2, pt. 5, p. 1020 ( ez parte, non Say). Description.- Shell of raedi-um size, thiii, raoderately elong- ated, inegnilsteral, slightly ca^ ve:^. anfc er iorly, eornoreGsed and fle:^ed posteriorly; atit ero-dor sal margin excavated near the urabo, roioiiding into the broadly ronncled anterior cnci; postero-dorsal msrgin straitrrt, meeting vhe guu o. laicated nitixln oi" the narrow posterior slope at a sharp angle of about 110 ; base asymnietri- cally arcuate, being more convex Tjoster iorly ; umbo aeufce, placed behind the median horizontal; post'.rior carina lo"", but v/ell-de- fined by the change in direction of the concentric sculpture, -olaced near the rcarjrin: S",rface sculTotirre"- with relatively fine concentric a:aellac-, aoru^tly I'lexed at the posterior carina and slightly archer! on the posterior slope; right valve with "-eli- de fined laterals. Pi: .ensions.- Length, 1 .5 rm. ; alt., 12 nini. ; semidiani. , 3 mm. Rein arks.- The collections at hand hnve furnished a sin^-lo right valve of this variety, •.vhich differs from the uypieal aequistriata, ranging from the Ohipola to the Recent, by being more elongatet^, more inequilateral, ,mor e produced and hir'ht-r anteriorly, v/ith finer sciil-ptitre, heavier right posterior cardi- nal and more Aista.t laterals. Because of its relatively large size, height atid strong posterior fle";inre it is readily disting- uished from the associated Tellinas. Occurrence .- lower Miocene: Bov.den heds, 3owden, Jamaica (Dall, 1900). - 485 - Section ■•hyllodiua Dall. TEILirA (PEYLIODIITA) HAIISTREPTA Dall- Tell ina (Phyllodina) halistre-ota iJall, 1900, ?rans. Wagner 7re© Inst. 3cl., Philadelphia, vol. 3, ot. 5, p. 1023, pi. 47, ri?:. 17. Desoription.- "Shell compresser? , I'lattish, suhequilateral, lon,'?:er than hip-h; uc-a -g small, low, r^. t-.tJi-ibliug a pustule on the sui'Hiuit of the broad smooth nepionic shell; surface marked ant- eriorly v.-ith ra.ther close, low, elevated, concentric threads '.vith about equal inters )acos; near the posterior third of the disk these threa'^'s become less numerous o^ the cessation o'" alt- ernate threads, making the interspaces wider, i^^/hile the persist- ent threads bcco::;.: lamellose; xu ji.u -./pt, ■. ;iieh is a yoivap: shell, the dorsal m.r-in is not coronate, but in an adult there are probably dorsal scales c orrespondinr to the later lamellae; hin.^e normal for the section, pallial lii.e o lij^jure. Ion. 9, alt. 5.5, diam. 1.2 mm." "Althou^^h this specimen is young, it is sufficiently char- acteristic and visti..ct to be recognized, though the adult very liKeiy reaches twice or thrice the size of the one described." (Dall, 1900). - 184 - Type log alit,y.- Bowden, Jamaioa. I^emarks.- This species has not an earc' in the col..eGtionG at riand. It is hardly? t^"pical of the section since the sculp- ture does not rise above the dorsal nBr;in - a condition vrhich may as suggested above, be ''i-e to i-ninaturity , Occurrence.-- lower Miocene: Bov/den beds, Bowden, Jamaica (Dall, 1900). TEIIjElTA (PE:;^ILODIi:Ar) LIl'DSAYI n. sp ', Description.- Shell of mecLium size, moderately Inequilateral, moderately inflated; roinded anteriorly; posterior end obliquely sub- truncated above, base frentl;; arcuate; dorsal f.^rc'-ins almost ntrair-ht diverging at an angle of about 140*^, the anterior longer; umbo low, acute, situated before the nedian horizontal; siirfaoe, except near the uixibo, scul^jtui-ed ^;;ith relatively c^riS-oicuous , evenly STaced, ooncen\;ric striae, becomin:- coarser pos~eriorly by the ter- inii.a.tion of sorae of the striae, the remainder becoming more 1am- elloce; left valve with stron? ca-rciinals and obscure laterals; rl-]it laterals strong; pallial sinus obscure. I)l".iensions .- I-en th, 18 naa. ; alt., 11 ■m. ; semidiam. , 2.5 mm. Remarks.- This species is rer)rese:±ed by a right and left' valve. On the right valve the sculptui'-e becomes more cons ^icuo-.is- ly coarser posteriorly. The sculpture is not typical of the sec- tion sin -re it i s finrr than us 'ml and tae lamellae do not rise above the dorsal m.ar.~in as crests. The ore sent form ;liffers fixjm halistrepta by being more conve:-:, vath finer sculpture. Occurrence.- Lovrer ITiocene: 3owrlen beds, Bovrden, Jariiaica. - 48 6 - Section Eur \ te ] 1 in a I? is cjae r . «> ■TSIIIIV: iEimYTELII"'A) sp. ind.e.t. Tellina (Eur^ tellina) sp. Dall, 1900, Trans, 'fegner Free Inst. Sei., Philadelphia, vol. ", nt . 5, lo. 10r4. Fragments of a snail Tellina,. apparently refer/able to this section, are present in the National Iliiseum collection and. also in the collections at hand. The shell is noderateli" convex and moderatelj? inequilateral; the pee tero-dorsal margin e xcavate :; the sculptitre consisting of fine, relatively," distant, regular concentric striae that "oecome slifi-htl;,; lamellose posteriorly. Occurrence.- lower I'iocene : Bowden heds, Bowden, Jamaica (Dall, 1900). '7 - Subgenus Moerella Fischer. TEIIII'A (MOEHEIIA) SIKPSOl'I Dell. Tel Una. (I-Oerella) si2;psoni Dall, 1900, Traxis. ?/agiier :?ree Inst. Sci., Philadelphia, vol. Z, pt . 5, p. 1024, pi. 46, fig. 12. Description.- "Shell small, inflate^,, equi valve, vei'^^ in- equilate-^al, jolished; anterior dor fjal slo"pe rectilinear, anterior end rounde ' , base convexly arouate ; posterior end very short with the extremity bluntly pointed; beaks low, somewhat opistho- gyrous, with a perceptihle la.!.rLle; hiixge norraal, pallial sinas extending nearly to the anterior a-lductor sear, mostly confluent belo'vv. Ion. 7, alt. 5, diam. 4 mm." "This form is v/hat "-'■o identified as T_. c une at a d ' Or b i gny . but the latter is less inflated and less flexuous behind. T_. sinpsoni sornetii:;es ap ears perfectly smooth, but other speoimens show increment al sculpture." Type locality.- 3ov/den, Jamaica. Remarhs. - T_, sirapsonl is distinguished by its decidedly inequilateral outline, convexity and sli-ht posterior constrict- ion. The surface may be sculptured v/ it h fine concentric striae. 488 - Gabb's (1^ Santo DoKiinp-ian T_. oimeata 'Orbigny is more like that (1). Trans. Am. Philos. Soe., newser., vol. 15, p. 249, 1875. recent species than sinipsoni, being less conver-. than the Bowden form, more evenly romide ''l loosteriorly, "-ithoiit the nosterior constriction and with rather rc-giilar, fine concentric striae. Oecairrenoe.- Lov/er Miocene: 3ov;den be '-Is, Bowden, Jaraaica (Dall, 19^0). T5L: IRA (T.:OSSELIA) HSDSRSOri Dall. TelliriL ' Mo«rellaJ_ hendersoni Ball, 1900, Trans, ''/agner ?ree Inst. Sei., Philadelphia, vol. ?, pt . 5, pp. 1024-1025, pi. 46, fig. 5. DesQription.- "Shell small, raoclerately conve- , verj/ ineq-.ii- lateral; from resenibling the oreceeding species _T. sinrosoni but less inflated, riiore rG~-iilar, r.'ith posterior en. not constricted or markedly? flexed; surTaee polished, v/ith, except near the beaJcs, f ne, rather distant, concentric threads, which on the basal half 01 the posterior end rise into er-'tremely delicate lo\v lamellae; hinge norraal, strong; pallial sintis connecting the adductor scars and confluent belov;; there is a slirrhtly i-npressed narrov/ lunule. l-Q-n.. 7.5, alu. 4, lam. '^ -^m." "This soecies differs in soulptnTe, form of lihe pallial sinus, and other details from the other allied forms." (Dall, 1900). "S-^-ge local it--.- Borden, Jamaica. !^emarks.- _T. hendersoni shares v/ith j£. acrocQsraia the distinction of be in?? the most abundant member of the genus. It oloselj* resembles _^. oimpsoni. the most obvi vas differen-e bei::'^- the absence of a posterior constriction on the present form. Sep- arated on this basis, hendersoni is larger than sinpsoni, one of the largest valves of the former ayiecies . ,uat..-.ri.i;; o mm. in length. - 490 - 6 rnm. in altitude and 2 mm. in diameter, whereas the lar/rest valve of the latter has these 'imensions: length 6.5 mm.; alt., 5 mm.; diam. , 2 mm. Althori~h the aversfre hendersoni is less inflated than simpsoni, ao;:ie vaj.ves ^ re erually inflated. T_. aelontea )all (1) from the Ohipola marl, is smaller, less inflated, and (1). oe. oit., p. 1D25, pi. 46, fig. IG, 19 '.O. more elon:ure ; be'-rs in the post- erior third; ,^ ux ,.&'Jl covere ' v;ith extre;;;ely i'ine close-set grooves; sculpture as usual a li'tle stro;i-er near the postei'ior end; 'oeaks low, pointe \* lujiule obsolete; hi,iir>-e nomal, pallial sinus ob- scure in the polish ' " '-he intidrior ;x'ooaljly ■ ":• ■:1; r.o thickened rays. Ion. 5.5, alt. 3, diam. 1.5 ram." "This c all form recalls :'. sybaritica Dall (1) lecent 1). ?ull. I.Ius. v0rnt)t. Zool., .-arva.d, vol. '3, -o. 1-"1, 1881; vol. 12, p. 277, pi. 6, vis-. 11, 1886. which is a larr^er, more solid and more fle:-:uous shell, it "la^ not be fully adult, b t is iiOt r.e young of any of the other Species v/hioh v;ere obtained from the Bowden marl at the seme time." (Call, 1000). Type locality.- Bowden, t-'amaica. Heniarks.- This species is disting'uished oy its lev;, elonp:- ate outline and relativelj; sharp posterior carina, the shell "be- ins slirhtly depressed in front of the carina. The larp-est of the few valves at hand ±3 larger than the type, with the following 'iinensi'-^ns: len?-th, 8 nm. ; alt., 4 ma,; diara., 1.5 nun. A closely related species. _T. agria Dall (l), is foimd in the ^'ak Grove (1). lOG. cit., -.->. 1027, -j1. 1-6, ii---. -'1, 1900. "beds; it is slightly larp'er, more flexed posteriorly and v;ith more prominent sculpture. The ?lioc?^ne ^. i;m"bra Dall (?) reaches (2). loc. eit., p. loss, r>l. 46, fig. IS, 1900. a larc-er size and is slirhtly less inflated; otherwise it is very similar to -oharcida. Oe ear re nee .- Lower Iliocene : Bowden beds, 3owden-, Jamaica (Dall, 19 -^O). /I. -) rr _ TEIIIITA (AITtULUS) G01:IDA n. sp. Description.- Shell small, el""~'-^e, luiiiomily inflated, decidedlj^ inequilateral; anterior end broadly roiuide'"' , posterior end abruptly rounded below; antero-dorsal nB-rf'ln long, slightly convex, sloii.-' untl;; ; posteriori; the "mar,p;in sloping more steeply, base descending to'vvard the anterior end; umbo lo?;, sit- uated at about -he -oosterior third; posterior carina scarcely diff- erentiate" fro.„ tiifj ;' uiiural conve^.ity of the shell, the posterior slope rounded; external sculpture of fine concentric striae, be- coming slightly coarser -oosteriorly; pal- ial sinus obscure. Dimensions.- length, 7.5 mm.; alt., 4.5 -,.m. ; semidiam. , 1.7 mm . I^emarks.- -his species is re^oresented by s single left valve. It appears to find ius .;iace in the section Angulus s. s. near pharcida. ^rom that species it differs by being higher, more convex, more -oroduced "oos tcriorly, ■ ith a less nronoui'.ced r)ost- erior carina and vxithout the depressed, area in front of the carina' Occurrence.- lower J.'io cene : 3-.v7den beds, 'Bowden, Ja'nsiea. - 1- ''^ ^ - TEI^I^A (AiraUIUo) iPOMSA n. sp* Desoripti o...- :ihell small, elongate, v; el] -inflated, dec- idedly inequilateral; broadly rounded anteriorly, >5luntly pro- duced "below posteriorly; antero-dorsal rrari-in lonp-, straip-ht, postero-dor sal margin sll^rhtly excavate" along- the len.^th of the liprament, the remainder convex, roimding abruptly below into the slightly arcuate "base; ninhonGS low, placed at aboat the posterior third; posterior cari.io jjorly define , area in front of it slip:htly dep- ■, caiising the basal niarrvin to be obscurely enjarginated ; external surface scul|)tiired with fine, regular, consoieuoas concentric striae, becoming slightly lamelZar on the posterior deprer-sed area; hinge normal, th' right posterior lateral very VTeak; pallial sinus obscure. Dimensions.- -^ength, 5 lam. ; alt., 4 i:P. . ; seniidiam., 1.2 mni, Remarks.- T. a'oomsa is describe^- from tv/o right valves. The most characteristic festii^e is the fine, rep-ular well-develop- ed sculotijxe. Af:ide from the -x-uater prominence of the sculptiore, anomsa is distinguished from phsrcida by its greater inflation and greater height and from °'onida. by its le.^ ;sterior end, steeper antero-dorsal ~"^ :, :;, • -re -oronouiiuw joi.-erior carina and accompanyin- degression of the shell anteriorly and acGomioanyinrr deT)res:"ion of the shell anteriorly and insinuation of the mars: in. Oeourrenee.- lower Miooeiie : Bowdeu Leds. .3owdon, Jamaica - l-':3 6 TJIITIM (AJ^GUIUS) ^:iOV/iyi n. sr). Description*- -^hell small, thin, clon'^a/';ecl, moderately in- equilateral, moderately convezc; rouMed anteriorly, posteriorly almost vertically sub truncated below; ant ero- dor sal narpin lon.^', straight; postero-dor sal mar |-^ '-liprhtly eizcavated near the umbo, Joining the subtrurioated posterior cnd~ at a subrounded angle of about 110 ; wabo acute, placed behind the median hor- izontal; posterior carina poorly defined, rounded; surface smooth, or bearing a f ev/ distant concentrio striae; hinge of the left valre normal, the cardinals weak; right valve not known; pallial sinus obscure. Dimensions .- Length, 4.5 mm.; alt,, 2.5 mm.; semidiam., 1.2 Rena rk s . - _T. bro\mi is represented by two left valves, the type beii^g sliP'htly smaller. It is di stine'iiishe d from the young of the coe^ristent members of the section by its more prod- uced and subtruncated posterior end, slightly excavated rsosterior dorsal margin and -ooorly defined posterior carina. This species is named for '. . B. Brown, a member of the early Jamaican Survey. Occurrence .- lower Miocene: Bov/den beds, Bowden, Jamaica. — ''-0 7- TELTirA (AlIGULUS) P.2ES3A Dall. Tellina (An uluslpressa Dall, 1900, Trans. Wa=fne r Yxee Inst. Sci., Philadelphia, vol* 3, pt . 5, p. 1026, yl. I?, f % . 5 . Description.- "Shell tlain, Gomprecscd, inequilateral; heairs low, hardly interrupt ing the dorsal profile, but sharp an(l al- most pustular; lip-ar;'ent rather long, hinge delicate but nomal; surface polished, with rather distant^ fine concentric isipressr-d- lines; the posterior dcrsal slope V7i th s;oarse, shario, liltle elevated Goneentric lamellae; near the beaks the shell is smooth; interior with a faint anterior elevated ray which separatee the adductor scar from the anterior part of the long, hifrh pallial sinus, which is 7;holly conflu-ent belor.-; the interior more or less obscurely radially striate. Ion. 12.5, alt. 7.5, diara. 2 mm. " "A thin and delicate specie a ;.j. gu i.o observable fle--:ure or rid.ee on the posterior end., and vhott especial criaracteristic is the high dorsal profile behi;/! the beaks." (Dall, 19')'). 'l^;:pe local it;;.- ^liipoia --iiver, Clalhoiui Oomity, "lorida.. Remarks . - On the valves at hand the shell is slightly raised on the dorsal half of the radial line near the riosterior end along which a carina is usually developed. ,7hen the shell - 1-98 - is especially tliin, and therefore subtranslucent, obseiure radial narki.-igs are visible external Ij'. OcGiirreiicc .- Up-oer Oligocene: Ohipola iiiarl, j'lorida (Dall, 19 >^) I LoK'er l.rioc ene ; Bowden beds, 3owden, Jamaica (Dall, 1900). Section Soissula Dall. TSILirA (SGI3SIJIA) SCITULA Dall. Tellina ( Sgissula ) sjitala Jail, 1900, Trans* V/agner ?ree Inst. Sol.., Philadelphia, vol. 3, pt . 5, p. 1028, pi. 17, fiP'. 15. Oesori -.tion.- ''Shell small, thin, elonp-ate-ovate , polish- eel, inequilateral; roiHidecl Ir: front, noci cratelj^ pointed behind: beaks lor;; suriaee with Une, r cf.'vJx:. r, rather close striae e::- t ending obli-'^ely "backward t owa'rds the hase, with more or lc;.s evident microcco oie r\- 'ial stri'alstion ; posterior dorsal areas iciniitels^ Goncentricallj v/aveo.; interior v;ith no thickened rays; hin.5-e nornal, vex'y delicate; pallial sinu.- long, hirh, normal. Ion. 8, alt. 4.2, diain. l.r; mni." "From the young of _J. iris Say (1) Heccnt of the same size (1). Jour. Acad. I'at. Sci., '"hil i Iphia, vol. 2, p. , 1822. it is a,t once distinrniishable by the much finrr and closer and more oblique striatic- ■ ..^ more pointed posterior erJ^ .^ (Dall, 1900). ?y-pe locality.- :■ ow d en , Jama i c a . riQTiBrks .- - .e posterior carina is v/ell- do fined, but lov;. Since this species is the oiHi' aQmbor ox' t ne aectioii Lt is conspicuocis for its Q-olirae ?tria.tions, v/hich raa;;, bov/ever, he Q'lite 'I'bscure. Qooarrerics ,- "pper Oil. e: Santo Domingo (Dall, 19'~*0) ; lower Miocene : Bowden heris, ^.ov,':'en, Ja;..aiGa ("Dall, 1900). - 501 - CenuB 3 T 1^1 a I II. A Turton. :-3i?RICIIIA ?I:-;iP0HI,II3 (Linnaei^s). Te llina -oi s Ifor mi s Ilnna- us, 1756, ';. ITa-I: . , e>^. 10, p. 677. Oar Til run d isoor s Montapru, 1S05, '^est. Brit., p. S1-. tellina pisiionnis Idnnaeua, ;ii.iu^ , 1647, .aieii. Jonch., Te llina. p. Sol, pi. 51, fir-. ?0. Strjgilla pislformis ( liiinaeiis ) '^abb, 1875, '^rans . Am. Philoc. 3oe . new ser., vol. 1\ ;. ' ^ : trig ilia pisiformis (linnaeus) Dall, 1900, Proc. U. S. !'a/. :'us. , vol. • : , . 3trigilia rlGiforrais (Ilnnaous) Da]l, 1900, Titans. '.Vaguer ?ree Inst. Sci., Philadelphia, vol. 5, pt . 5, pp. 1058-1039. Strigilla nisiformis (linnaeus) Ball and '-"inipson, 1901, Bull. U. 3. Fish Gorxi., vol. ?.0, pt . 1, p. 482. ■ Description.- Shell sniall, short-ovato, str^nrl?: inflated, inequilateral; broaolv- ro'.iiTded ant eriorl^j- , more at'jenuaten, but rounded posteriorly-; ant cro- dorsal r.iarr-in short, straight or Glii-»-htl;7 eoncave, loassing ahra-jtly into the "JatcraJ. r.E.ri^-in, •■:iozt- cro-.'.oi.-;^.. ;: longer, Gtraig'ht or sli^htlj- convex, rounding iviore broadlj" into the posterior end; umboiies turaid, broad, erect, placed nearer ths anterior end; areas before T'nd behind the -umbo feebly inrnressed; external surface sculp tiirr^ with d ivari casting- striae, passing- o-olicuel^v over the ^restcr part of the shell, gently flexed n/Dv/ard aL on? a rpdial line in the anterior third; behind v^hich the striae are finer and sharply angiilatel once or twioe, forming a zigzag soiilptiure; hin^'-'e with a povSterior and anterior lateral in each valve, tv.o ri^^-^-'- '^--^rdi-.als, the posterior iarg-er and obscurely bifid, t',vo left cax'dinals, the anterior small and scarcelj^ differentiated from the margin. Dimensions .- length, 7.5 :;im. ; alt., 6.5 i-im. ; seraidiam., 2.5 3emar]£S.- The characteristioally sciUptured valves of this species ax^e numerous -..x... j^.... "t be confused v/ith any ot'-er raem- bcr of the fau^ia, the Divaricellas, the only Other divaricately sculptitred forms, h- ving an orbicul.v.r outline ai,id the sanie type of soul'ture over the entire dislt. The largest valve has the following dimensions: length, 9.5 mm.; alt., 3.5 mm.; diam. , 2.7 mjp.. The sharp ahange in soTi!.pture poBtoriorly occitrs on a line alo"Ag which, in some s ecimens, a slin-ht ridge Is developed. The posterior sculptiixe is variable, being sharply anf^ulate, once or tv/ice , or merely passing to the nargin at a sharp angle. Young valves are more orbicular fchan adults. Dall (1) renBrked that Ouppy reported 3_. carina from Bov:- ( 1 ) . loo . c i t. , TrajTB . '.Vagne r Inst , , 1900. deii, but Gup::>y's 1874 clieck list (l) -ives that S;Tecies from (1). TgoI. •^'^atr. decp'r- ", vol. 1, p. 441. the Pliooeiie of Trinidad, Occurrence.- Upper Oliprocene: Santo Dominro (Gabb, 187S) ; Lower Miocene: Bowden beds, Bowden, Janaica (Dall, 1900) Pliocene: Trinidad ( ? "^-^-^-y, 1874; Dsll, 1900)^ Pleistocene: Antillean region (Dall, 1-300). Recent: From Hatteras south- ward throuc-hout the Vest Indies to Guadaloupe. Geuus I>1A.OO!!A Leach. Sxxbgemis Psaminacoma ' Dall. Section Psararnacoraa s. s. MACOliA (PoAiiaiAOdji) ^.^^J^A - 11. I.'Iacoma (Psaiarnacoma) traota Dall, 1900, Trans. V/ajrner T'ree Inst. Sei,, Philadel-ohia, vol. I?, -nt. 5, p. 105?, nl. 47, fig. 13. Pe script ion.- "Shell snail, tii in, rather comcressoci, , elonr- ate'l, inec iiila.tcr al, the anterior end longer; o&a.is lov/, not con- spiGuoas ; posterior end slightl^' flexed to the rifht; anterior end his-her, rounded, -oostcrior attenuated, iDlimtly terminated; surface oniooth except for faint incremental lines; iiit-rior ( in- acGessihle in the specimens). Ion. 12.7, alt. 5, diam. P- Gim." "This sr^all species differs frora the ^:onnp- of the ne-t I IT. olivella DallJ in its more at -enuated posterior enc; and slight flexure." (Dall, 1900). Trre 1 oo al 1 1:; . - '3 or d • n , Jaria lea. -weraarhs.- A single lar^re loit valve is riresent; it has the followins- dimensions: length, H2 ram., alt., 10 mm.; diam. about 2.5 ^ir;i. The s^irface of the shell is not -oerceptibl;)- fle::e''l -oont- eriorly. As in the case of the Y.atioa&l r.useum specimens the interior is not accessible. The discover:; of so larpe a valve - 505 - gives traota. about t lie sa;ne dirnensions as the .Tssociatel o 1 iv e 1. 1 a , but the.-: niay he "iistingaished hj7 the lower outline^ nore attenuat- ed posterior end , loiip-or and s-^cener -oontero-'"! or nal r-'Trin of traota. Occurrence .- Uooer Olir-ocene: Ohi^oola :;!srl, Florida (Dall, 1^"'')« Lower Miocene: oowden beds, ;3ov,'den, Jamaica (Dall, 1900). rAGOlTA (PSAIil^AOOIvIA) OLIYEIIA JslL i:aGOTna ( PsamniaG oina) olivella Oall, 1900, Tra-ns ^ V/a^-ner 7ree Inst. 3ci., "hiladelphia, vol. , . , j. l"'"'.-, nl. :.-7, firr. 20. jesoriptio::.- "Shell lar c, o.j_^.., .,iu '' : -'onves, with rather full, oonspicuoac beaks, equivalve, very inecn.ilateral ; anterior ciorsal slope rectilinesr, anterior end rounded; posterior dorsal slope i-~i--^ijr coacsve, -^■r^'^-'^- -"lor end ---^'h -^^/•'-er, round- ed belo".', hli.mt terminally and subangulate at i^s .j '.motion v/ith the cor: £l line; an elonjrated lunule and escateheon, nodcrately impressed ._^.i.. not very definitely" limited, are Dxesent; surface smooth, except for lines of grov.th and on the ridge bounding the lunule, v/hich is sli!v-htly undulated, especially near the beaks; hir^ge normal, teet: rather small, pallial sinpis ~ibbouB, short, partly j-'ree belovv. Lon. '=3, alt. 13, diara. 5 mm," "This soecies recallr K. ( Pssminaooraa) elongata Eanley (1) of the recent Panama fauna." (Jail, 1900). (1). Type locality .- Bov.'den, Jamaica. Reniarks .- This species is not represented in the material at hand. OooTirrence.- Lov;er Miocene: Bov/dect beds, Eo7/den, Jaruaica (Dall, 1900). r, ;-i p S^^tag■en^^s Gyraatoiea Dall. T r AOO^','. f '" ^TOIOA) VEITDRYESI Ball. Macoria (Oy^-atoica) vendr.yesi Dall, 1900, Trans. Warner "^ree Inst. 3oi., Priilaclelphia, vol. ", "■ . 3, p. IO06, pi. 46, •Ft (T -^ X J. ,^ • t.y . DcwO^ 1 j^ 1 ■-..- "Sliell iuiii'vice, Li^iu, ^ie:;-aout;, rostrate, in- equivalve, inequilateral, i?aping behind, moderately inflated, anterior end full, rounded, shorter; posterior end long'er, recti- linear a"bove, sinuoub below, oroduoe'' into an obliqaelj" trunosted rostrum; beaks low, pustular, left valve slifhtlj- loss convex Ifchan the right and a li-rle lonper, surfa-ce ooncentrieall^" irrep'alarly undulated ex^e^jv ju the pOij!^f.rior doroal aroa, .,i-ieh is transverse- ly striated; pallial sinus small, short, partly confluent belov/ v;j th the pallial line. Lon. 7, sit. 4, dipm. " ran. "This species is cons_'-^eri;jl^ o-iuliLr \...i^a the recent !I. ori- entalis Dall [1) snitillean , the concentric v;F.ve-li"e sculT)ture •;i). ?roc. U. 3. l^at. :,.:io., vol. 12, o, £73, pi. 10, fig. IS, lo39. is finer and less broken, and the shell is relatively more inflat- e''. The teeth are quite feeble and minate." (DpII, 1900). _ -^09 - T^^pe locgvlit;, .- Bowden, Janiaiea. ?.eniarks.- This sneoies, the earliest member of the siiId- genus, is represented by several valves, of r/hich the largest is slio:htly lar.o'er than the tj,"pe. The rjnbo is situated behind the me ian horizontal, so that the anterior end is longer. ?rom the other :?ellinidae this species is at once disting'uished bj- its decide^lli? flexed posterior end and relatively coarse, irregular coneentr ic sculpt are . Occur rence.- lower Miocene : Bov: den, beds, 3o?;den, Jamaica. (Dall, 1900). - 510 - P ami 1 J- S erne: 1 i dae . Genus SEI.IELE Schuiaaeher. Section Semele s. s. SEfSLE OAlIIGONainnATA n. sp. Ijescilption.- Shell small, cubelliptical, r:v^ " •':el;." in- equilateral, raoderacely inflated; roujicTed anteriorl;,- and post- eriorly, the ciijrve of the ajitei^ior enrl more convei^:; antero-dor- sal marc-in straight or L-ili.^htl;; coi.cave, postero-dorsal shorter and slicihtlv conve::; base rentl;; arouate ; umbones lov;, acute, sit- uated behind the median Yertisal; external surfa^^e rcticulately sculptured with strong-, eqiiall;;,' spaced concentric lamellae, their ed°-es thickenect and orenulated at the points of intersection V7ith 'orominent radials, the rnr'ials so.iars.ted by s1i":htly v.'ider inter- spaces and closer on the me ;ian portion oi the sr.ell; near the antero- and postero- ventral margins conspicuous nodules developed at the intersections; between the concentric lamellae fine cor,- centric striae present; hii^^e noruial, the right laterals heavy. Dinensions.- lerjgth, 9 mm,; alt., 6.5 mm.; semidiam., 1.8 mm. RenErhs.- The snail, beautifully Dcalptured valves of this species oon not be confused with any other mO'Viber of the fa.U!ia. They closely resemble the young of the Pliocene to Recent 3. >11 bel"^ astriata (Oonra-''. ) (1), "but are raore inflate '1, rn're bz'oadly (1). Jour. Acad. l-Jat. ScL., Philadelphia, vol. 7, p. ?.39,pl. 20, fig. 4, 1877 (as Amphidcsma bellastriata) = Amphi- deama oaricellata d'Orbi^ny, 1853. rounded ant eri-^'""' - °n'^ -v^o•^- ri orly , v.lth, on the v;hole, fev/er and broader rsdialsi. OGCiirreiiQo .- lower I^Locene: Bowden beds, Bov/den, Jamaica. Geniis AB2A (Lea oh) LairBrck. ABRA TPJ.^TCrULATA Dall. Abra triaap-ulata Dall, 1900, Trans. V/agner ?ree Inst. 3ci., Philadelphia, vol. ?, pt. 5, p. 997, pi. 49, firr. 4. Dr scription.- "Shell small, thin, polished^ siihtrironal, nearlj^ equilateral, v/ider than hirrh, moderately inflated; beaks pointe'-'', not mnoh elevated, the dorcal margins straight, diverg- ing at -he rniiho in an angle of somev/hat over ninety degrees; "base arcuate; anterior enr! sli??htly lons-er, rounde:'; posterior end shorter, more pointo ; c-.\:erior polished; anterior dorsal mar^-in in the right valve vath a lateral tooth at some distance from the hinge-plate; on the posterior margin' is a. short fold not elevated to beGo:.:t; c jooth; -^-h^' left valve shows no lat^als. Alt. 5.5, lat. 5.S5, diarn. '^,0 :ta." "This STseeies is not uiiliire A. lioica Dall (l) of the recent (1). Bull. IIus. Gompt. Zool., Harva d, vol. ', p. 17.?^, laai, fas Syndosmya lioica) ; vol. IT, p. 273, pi. '■ , fig. a, 1886, fauna, but of a more ev'-.nly tri ortline and with the ant- eri'.r part less produced." (Dall, 1900). T^pe loc Blity .- Bo';vden, Jamaica. - ^1 Remarks.- Sevex'al valves of t?iis species are at hand, the larp-est beiiio- larger than the t x . The high, triffo.'^al oiitline an^ relati -ely stron?? i -f 1 ation re the flis tin =m shin;? features. Toward the margin faint sag:?-estio. s of radial myrkin'^s are occas- ionallr visible; they '^o not, however, rise above the reneral siarface of the shell. Occurrenie.- lower Miocene: Sowden berls, Bowden, Jamaica (Dall, 1900). - 51 \ - ABRA DEUTEHA n. sp» Deserj-Qtion.- Shell sr^.all, thin, • - ell-infls, ted, siibtric-on- al, sub equilateral, iDoin,? slightly/ more ororiaced anteriorly; dorsal raarcrins virtually; straij^ht, the anterior sll'-rhtlsr lonsrer; rour.ded anteriorly a::d noE-^c-riorl;; with a very slip-ht constrict- ion near the posterior end; Dace o.eciderLly arcuate; umlDO tumid, low, subceiitral in position; external surface sculptured with very line, refrularly soaced concentric striae, occasion-ally en- phasized into snari^, thin lar..]. " , and fine, r.iore ooscure, widely STScerl radial nErkinc-s ; right volve v.-ith a narrov/ resiliary- .groove, the cardinals ai- laterals, relatively stron?. DiEiensions.- Lat., 4 ..v::i. ; ali;., ; .5 ra:.; semiuiara. , 1.6 nim. i^eimr :s.- A. deiitera is known from two ri^rht valves. It is distinguished from the yo.ing of A. triarfulata by its ler-s acute umbo, greater inflation and the presence of v/ell-def incd s.?xilp- ture. V/hen the shell is translucent the radials are very ob- scure. Occurrence.- lower lliooene : -^a';den be Is, Bov.'den, Jamaica. - ?15 - I?a:ailT/ iJonacidae. r'^enus. DOrAX (Linnaeus) Earcarck. DOV.AX L^rrozi n. sp. Donax aeoualis Dall, ig^O, "'r- v--. -Tr^r— pr "^ree Inst. Sci., 'Phila- delphia, vol. r, p::. 5, p. 9o6, (ex parte, non c^ebb, 1875). Description.- Shell small ,_.,-t hi n, su.btrojisluoent , moderr'tely inflated, tnoderately inequilateral; antero-dorsal niar-'in Ions?, strai^^ht, ■^he 'interior en"' -^o^-i^.- . r-nuJ:o v-n_ -n -.-'--t ■^'ar^.-in alisrhtly convex, ti.e posterior end produce i and abtuptl^- rouiided "bel-ow; base slightly- arcuate; posterior carina prominent, subrounded, the posterior sItv-^- almost flatterjer"; ■f^hp f^-^-^rf^-r^ ^ „ \ rr pt ner^r the umbo, bearing distinct, fine radial , standing in relief onl;" on \7orn s;irfac!es; left valve with wealc laterals, received into vrell-marked sockets on the rip-ht valve; inner ventral '-r- gin of the valve '//ith fine erenulations, extendizig' up a short distai'Lce on the posterior margin; pallial line obsciire. Sinensions.- Length, 5 mm.; alt., r. nni. ; semir'.iam., "^ r'-,. Remarks. - fragmentary valve is slightly larr^-er than the tyoe. The rarlial markinr:: are distinct, but do not consti- tute striations ezceot v/here the sra-iace is eroded. This species _ 515 - has been confused with. D. aequalis Trabb (l), desGi'ibec' from (1). ■'r^ns. An. Philos . Soc, ner s.->r. , vol. 15, n. r49, 187!?. Santo -iJominffO, but that species is larger, !■ lOqailateral, v.'ith a shorter and less steep ant ero-r!orsal margin, more bluy.t- Ij" ro^mdeo anterior end, straigrhter postero-dor sal niarf^-in and ctronc^er hinge. The Oosta Rican Pliocene D. mqenensis "-sbb (^) (2). Jonr. Aoad. Fat. Sci. , Philadelphia, 2nr] ser., vol. 8, ■n. ?^71, .^1. 47, flo-. 72, 1881. is smaller, nore elongated, v/ith a more rounrled posterior slope an''' '■-'Te conve:-: postero-dorsal raarp'in. The nanie is given for ilr, Arthiir. Lennox, a nienber of the earlj? Jamaican Sirrvej'. OoGurrence.- icwer Miocene: Bov.den be^ls, 3or;den, Jamaica. - 517 - DO! 'AX OYT/IOBIA n. sp. Description.- Shell small, elongate sulDelliptical, moderate- ly inequilateral, niod eratel:: inflate'; roiTndsrl anteriorly and posterijrl^, , iie f.nccrior cn;i nore at cenuaued ; unioo lev/, stro.ir- Iv opistho-yrate, situated behind the nieclian vertical; external sciil"otiH'e of fine, rcpr-al?.r, impresse'"'' concentric strie.c, "becom- ing e:;owded tov/ard tne ui::bo, \7i th prominent narro.. radials on the posterior end, the rsdia,ls hecomins' weaker over the middle of the shell and obsolete anteriorly;; left vrlve r.lth a TDromi- nent prosodetic resiliary groove, follov.ed, posteriorly^ b- the cardinals, the oosterior small, compresse '. , its axis almost at right angles to that of the anterior; ri~ht vrlve '.vith t?;o c: - inals; on both valves the hime plate na-To.v, ^ne laterals relat- ively distant and strong; inner margin of the posterior end of the shell wea^cly crenulatel; pallial sinvis mor' ly rleep, roiuided. Pi ..erisions.- Length, 6 ram.; alt., 4...' :.iz:.t ; Ljcnidiam., £ mm* RemarL'S.- Several vr-lves of this beautifully scu] nture''. species are at hand. It has a more modern arjp?ct than the rroup to v/hich lemioi^ii oeloriTS and can not be co^iiuDe.i v/ith that soecies. The posterior radials are subangular, separated by narroT/cr inters-oaces and nodulated b- the overridinr concentric sculpture . Occurreii-e.- Iov;er Miocene: Bov/den beds , Borden, Jamaica. - 51'3 - Supe rf arailj? S 0 I E K A 0 E A . ?amil3? Solenidae. Genus PSAH-MOSOIEIT Risso. PSAI.MOSOLE"^ OUlvTINC-IAJIUS (Drmlrer). Macha ^umingiana Bunlier, 1861, Proc. Zool. Soc. London, for 1861, p . 4-2 5. ?ap-eliTS liioeatxis Gaol;, 1881, Joxir. Aead.. Hat. Sci., Philadelphia, 2nd ser., vol. 8, p. ."^VO, pi. 47, fig. 71. I.'aotra multilineata -^all , 1898, Trans. 'Va.frner 7ree Inst. Sci., Philadelphia, vol. 3, pt. 4, pi. .V:8, fig. 15. Psamniosolen viokshurp-ensis Dall , 1900, idem, pt . 5, p. 950 ier. oarte, non Aldrich, 1385). Psanrnosolcn ^-gmirigianut: Dxuikrer, Dall, 19""'0, idem-, p. 961. Solecxirtus c mtiiugianus (Dunlrer) Bose, 1906, Bol. Soc. Geo?. I'-er^ico, no. 22, p. 82, pi. 12, lip:. 5. ? Soleeurtus R-atanensis Toiila, 1908, Jahrh. 11. -k. p-eol* Reich- sanstalt, vol. 58, p. 7.'^2, pi. 28, fi??-. IE. Desari otion.- "Testa ovali, oblnnra, conver.a, angusta, que rotiiiidata, alba, striis increnenti concentricis lineisque ob- liquis elevatis sabtilibuc instructa, epidrrmlde sordirla, teii^vi, decidua, sublamellosa induta; umbones oax-vuli, £inte-me "'.iani, obtixsi; basis dorso subparallela. Ion. 41, alt. 17, lat. 11 >19 - Dim," (iJiiiilcer, 18i;l), T^-oe looallt:;^.- Antilles. Shell Itrce, thin, elonp-'ate-quadrate, clecidedlT/ inequilat- eral, v/ell-irdTlatecl, Vv'ith a median shallow, broad depression; rounded anteriorl;'j and -oosteriorl^-, the carve hroarler anterior- ly; 'orcal and ventral rriarftins subparallel; antero-dorsal riars-in shorter and with a slightly steeper slope; ven"-r 1 marp-in sli.?ht- ly erarprinated nedially b*: the de-ore , area; iimhones low, ola.o- ed at about the anterior third of the length; anterior and post- erior carina broad, rounded, not differentiated from the general convexity of the shell; surf-ce sculptujred v;ith irregxilarly dis- posed increment als, occasionally emphasizen and fine, relatively closely spaced oblique striations, beginning oii the anterior carina, flexed upward over the posterior carina and continuing- across the posterior slope j but more obsciire ; hinpre normal; ant- erior muscle scar high, the posterior lower and lar>-er; Toallial sinus e:-:tending to a line be: "^ '''' "^'"^ umbo, larr-ely confluent below with the oallial line. I^imensions.- length, 48 mm.; alt., (umbonal) 19.5 mm.; seraidiam., 6.5 mm. ?.emar>s.- On the v;hole ti'.e -iov;den ?sa';rrosolen resembles Cr.e Pliocene and Kecent oumiiip ianus, althoup-h none of the specimens at hand are as lar~e as those fo\u-.d at later horizons. The close soacinr;- of the oblique lines on the 3o\vden soecir.iens is fairlj' constant on different individuals and they extend for- ward to the anterior oarlna; "but these featijres are not constant for the species. The tirpe of ?, vio>s"burg:ensis (Alrlrich) (1), to which the (1). Oincinnati Jour. l^at. Hist., p. 145, pi. 2, fir. 1, 1885 (as ^oloGurtus vicksbirir °rensi a) ; Bull. Alabama "eol. :'^urve; , no. 1, p. r7, ol. ?:, fi^-. 1, l-QC. 3o7;den form has "been referred, is much -mall , /.d V'/hen com- pared xith the ;;'0nr!5- of the '^.0"'r'e:- ' e r, less inflatp'"' and more z:^-'-" ' ' . ^j_-r^ji c-.io from Oatun, apparentl^.^ Toula's gatunensis, are slightly larger than the "•-■.- den ones, with the oblioue lines f'lrWTer apart s-,-,.^. obscure ra*?.- ial lines t '-'• •-^-.,,- .-- ^ - /r.tl^- seen on cumingianus. la's "Solecur r.ua (Llaeha) a':- Irillatus linn.", (?. ) (2). loo. cii. ., u.7:;i, - •"•- ■P • r.. -1 -| . 11. 1908. 1., -i.p-her luhuu.- rrith sli^-ht- Oec-'rrence.- r f^li (ioula, 13C0); Io..rx .liocene : (Oall, 1900). Plioo _; Limon Santa Taria ""atetla, 7era 3ru2, en at ion, j\v d. e a , Jamai c a ■■'0, 1881; Dall, 19^ . ^ ^"1 hat chic " , ^"1 ■ Sao PsTilo, "1 a (Uall, 19C0); .ocnt: ^'orth ^aroH to Superfcaili? LI A C T r; A J i: A Genus SPISUI.A . 3PI3TJM sp. indet. Dhe faTni?_5 ^-actrl'-lae ic r e'"vc£'e"ntoi3: bj'' . valve, apparently- oelonging- to '' 3pi:jula. .-i.e hinr'c is somewhat vvorn and except for the ] ' rior is inaoc- ^he shell i?? ^'i^all , siiheciiilateral, eloi''r''ate snhcllipti ", niocTerafcel; inflated, •■ - - _ ^ . ,^QQ-hi^ ercteriial surface. 5'c e ii.r r en c e . - low er Hioeene: ■BoT.-j.ei: , ryjC.ei^^ <;'u.:-Lai'.*a. '1 1 - '"ti '-.' n rl .-. ■--' Cell .7ILIx\. ■ jn, :iiVlLlA ZABBl v.. Deseri:-.'ti\. .- 3iiell s:;]all , thii. , - 3"~?1-, .-''.loeoiu- 1- ', ell-iiiflated; posterior end sli ' and more aTjruptly romiderl ; dorsal raarj-iriS siibeqn.al in length and tic - i'V '■'■?■ '•>-• '••311)0 ang'le; Tdepo ^ently a- ' ' ' llj; arcrcte; lun- oOiJKS tiiLiiiu, rela.'"ivelj' nro:.' , opi , oeentral in position; external snrfaoe soTxlptm-ed wi"?-' , ce--''-^- ■ :.;.,., ' ■ " ^ ^, - ---•'■ erlo " ; hing-e v/ith strong cardinals " _ te val grooves ".le rir-ht valve Ten- •'ell-'^e"' Dimensions .- T^vr--^-"'-', ' . ; " . , . . ; . , " . ^ ?.e^iBrV£.- -ecies ia reco -illy L' 'bi- lateral o- " , 2P:tJ''-'1'2 ' ' • i '"> '"> "I a ■'■ ' a ~' "^ ~ ^1^ aui3 3. trign; ula- ' ' ' ' "" teral, n: .intei." tl). !i?ranb. ^.- .. p. 91A, . , , 10, { Z) . Idem, . ■ ' , . , ;o/i_ posteriorly and with less conspicuous sculpture. S, f^aVoi re- seinliles more closely the Duplin ]^, lata Dall (l) and the recent 3. concent rica-G^ul a (2), of V7hlch are slip-htly more ineo'ii- (1). Idem, p. 914, pi. 5^, fig. 20. (2). Proc. Boston ^oc . i'at. ''-^ist., vol. 8, p. 280, 1862; Dall, and SiraiDSon, "Bull. IJ. S. 'B'ish ■-^omm. , vol. 20, vt . 1, "o. 174, pi. 58, fig. 12. lateral and more comnressed. Ihe Pliocene S. -polita Dall {^) is slightly larper, more ixiequilateral, more compressed, v.lth (5). loe. Git., p. 915, t^I. 55, fig. 17, IS-TG. feeble sculpture. ■The name is ffiven in memory of ".'illiain 'Tore Oahb, whose Santo Jomingia.- memoir is a classic in :;he -eolop'ical litera- ture of the 'Test Indies. Occurrence .- lov/er "'iocene : Bo -den be s, Bowden, Janaios. Super family -.M Y A J ^ A . Tamils; ^orbulirlae. ^enus 0 0 :-^UJ :■. i Brnr-ni dre ) I ama rck . Section Aloidis i.iegerle. CO-RBUIA (AL0I:DI3) ,-:a Dall. Oorbula vieta Guppy, 18G6, Qiiart« Jour. Gool. Soc. London, vol* 22, T), 480, pi. 26, fip-. 8 f ri ^^-ht valve); -n. ,-,nr, ^i. 26, fig. 6, (left valve, as ^r. cina tensaj e:?c carte. Oorljula dis^arilis (^pTdI), 187 J^, Trans. Am. Philos . 3og., new ser. , vol. 15, -0. 247, (non d'Orbina-;, ISoJ^); "]r--Gina tensr ,Qt>^p,. idem, p. 252. Gorb-'la vieta Guppj/, 1874, Geol. ^""ag., decade 2, vol. 1, -o. 441, (checlc list); Erycixia tensa,^'if?em, r). 442 (ex parte). Oorbula vieta Gup ^y, 1876, Quart. Jour. Oeol. "-loc. London, vol. .^2, p. 520; :"'rycir]a tens a,^' i'^ em, p« 531. ? Gorbula disparilis -abb.loSl, Jour. Acad. ^''at. 3oi., Phila- ., ZnA ser- delphia,, vol. 8, pp. ?;4?, 571. Oorbula disiparilis Gupoy and Dall, 189^, Proc. U. S. Fat. T'us., Z*- vol. 19, p. :^27 (non d'Orbieny, 185^^). Oorbula ( Aloi^^is) hetero.-^eiia (Gupoy Lias.), Dall, 1898, Trp/c. .'/agner "^Bee Inst. Sci., Philadelphia, vol* 3, nt . 4, p. 850, pi. |-*f, fir. 15. 34 0 orb 111 a heterop-ena Ou■:^^37, ".ro-un arr^ Pilsbry, 191], Proc. Acad. -at. 3ci., "^hila^'olphia, vol. G5, p. ?7.1. Descri-otion»- "^his form is very clo-oe to 2* vieta. n-f-- differs from it in hL^vinr ' beaks narrov7er, less elevate^., and less prominent, and the posterior -oart of the shell more pro- duced. Ion. 9.5, alt. 8, diara. 5 mm." f Dall, 1898). T;;pe looalit.y.- 3owden, Jamaica. Hight valve of nteditira size, high, decidely inflated, sub- equilateral to moderately ineo ■ dlateral, clir-htly more produced posteriorly; dorsal marrins subequal, both ooncave, roxmded anter- iorly below, posteriorly trujicatea below, base gently arcuate; i-mbones tumid, high, stronrl: incruve' and moderately to deci^^'er!- ly prosogyrate, subcentral in position; near th'. posterior mer-in an oiaseure carina present, lollov/ed anteriorly by a stronger, roadly rounded carina, the area betr/een the tv:o flattened or slightly depressed; surface sculptured v/ith concentric rof.ae of medium width; left valve small, elonprate subovate, well- inflated, moderately i-„ Hate al; roimded anteriorly, trrincatod r)oster- iorly; ant ero-dor sal margin si iP'htly concave, postero-dorsal slip-htly loni?er and straight; umbones tamld, moderately hip-h, ■olaced before the median vertical; posterior carina lo\'.', obscure; sculpture of obscure, fine concentric rugae, suppressed over much or all of the sr'jrfa -e and about ten to tv7elve very narrow radi- als, the posterior slope v,-ithout rrdial sc uJ.pt itr e ; the marrins ■7 _ Ox the lir-araent pit decidedly t hi cleaned axid posteriorly forming a projecting process. Dimensions.- A right v^lve : Length, 8 ram.; alt., 7 mm.; diara. , 3 mr.:. A left valve: Leno-ht , 5.5 mm.; alt., 4 mm.; diam. 2 mm. Hemarks.- Right valves of G_. heterogena are very abtmdant, but, curiously enough, left valves are much less numerous. The two can not be confused with the other Oorbulas, the right valves being recognized b:. its high, narrov; outline and the left by its more elon?rate ortline and radial sculpt:tre. Right valves dis- play an inconstant outline, some being more oroduced posteriorly; the largest has the following dimensions: length, 8.5 mm.; alt., 7.5 mm.; diam., 4.5 mm. iTie average valve is higher and narrower than the one figured b;; jail. Both sets of sculpture on the left valve are usually obscure. Axi interesting feature is the decided thicfeenin?? of the hinge-mar^^in on the left valve behind and luider the ligament pit. The type of £. vieta is from the Socene of Kanzanilla, Trini- dad, but ^uppy also reporte'' it from the "Upper I'iocene, Jamaica", confusing it ^Tith the present species. In the 1896 notice of Jintillean fossils Dall apparently consolidated both vieta and the ^o-.vden form with the recent 0. disparilis d'Orbigny (l). (1). In de la Sagra, Hist., phys., polit. et natur., de 1 ' lie de 'Juba I'ollusoues, vol. 2, p. 287^, pi. 27, firs. 1-4, 1853. (?rench ed). although the "Olifroeene of Jamaica" is the only horizon and local ity friven. Later in the V/agner Institute papers the three forms are differentiate t. Jhe Santo ■i-'oninfian form under the name disparilis a-^parently cannot "be distinguished from the Bowden soecies. ^rabo 's Gosta Rican Miocene specimens of dis~ parills (l) are poor b'lt closely resemble heterorrena. JTone of (1). loc. Git., p. 345, 1081. the Oosta Rican Pliocene disparilis (S) are as large, hut valves of the same size shov*' no constant differences. In both those (2). loc. eit., p. .'^71, 1881. cases only right valves are available.- for com'oarison. ■:'he recent disparilis is lar.eer, v/ith ir/ider and h'p-her umbones and less regula, r sculr)-':ure . Occurrence .- Up-oer Oligocene: Ohipola marl, "Florida (l^all, 1898); Oak '"-rove sand, Florida (Dall, 1808); Gatun formation, Panama (Dall, V.l 3); ^nto Jomingo (^Jabb, 187S; I'uppy, 187d, 1875); louver F.io eene : Bowden beds, Bowden, Jamaica (Gup-.^y, 1866, 187^.; Ouv.y and .Oall , 1895; TJall , 10Q8). i'ioGone: Ohoe"'-:?hatchie ijr.;iation, ':'lorida (Dall, 1808); ? 3apote, Jos a Rica (Gabb, 1881). Pliocene: Jaloosahatchie marl, Florida - 5S9 - Oall, 1838). , ..i„i,,, , g,,,^,,^ ^3,^,^. ,^^^^^^_ ^^^^^ ^^^^ (r.abb, 1881). Section ^iiiieocorbula Oossmann. CORBULA ( 0UTT;0G0R-3ULA ) SEHI , A Jail. ? Oorbula cubsmla-na C-upoy, 1874, Heol. Ilag. , decade 2, vol. 1, p. 441 (ex oarte, non d '01-131,^13-, 1855), C orb Vela ( 0 aieocor-oula) serlcea Dall, 1893, Trans, '.'/agner Free Inst. 3ci., Philadelphia, vol. 5, pb . 4, p. 848; 1900, pt. 5, pi. 36, fig. 8. ? Oorhulc serisea Dall, Brovrn and Pilshr: , 1911, Proc. Acad. -at. 3ci., Philadelphia, vol. G5, p. 371. Description.- "Shell much like the precedinp* species 0. seminella Dall in general form, hiit slightly ] _• and with less emargination 'beiie? th the rostrum, the sculpture, hovzever, is quite different, heing of very numerous, eciial, fine, sharp, close-set rihs, the interspaces crossed by fine, close, sharp radial striation, y;hich at ci. -\. istinguishes it from aiiy of the allied si^ecies. Both valves are similarly sci^Lptured, the sculpture "becoming obsolete on the bt.?ks. Ion. 4.5, alt. 5.5, diara. 2.5 mm. "^^ largest vr-lve measures 5.4 by 4 mm." "As the ri e not overrun by the radial sculoture, the effect is not reticulate. O.lavelleana Orbirny, of the recent Aiitillean famia is said to be radially str\'^'"f--\ but I have not •1 _ "been able to obtain soeeinens of it for -"^n ^ariL;on." ( Dall, 1890) 'Jype losalit:;.- Bor/den, Jaraaica. The shell is small, well-inf latel, moderately inequilateral, elongate, rostrate; left valve slightly smaller than the right; abruptly roimded anteriorly, posteriorly the margin sloping above, obliquely subtnu-ic belo?/, the angle betv/een the two portions, obt se and subrouiide "^ to roiuided; bas^ rc.-tly arciiate, sli--^htly emarginated posteriorly, the postoro-ventral arg-le sharp and less than 90 ; posterior carina well-define ^1, sharp or subrou.d- ■e^ , ventrslly the sn.rfaee of the shell slightl^ depressed in front of the carina. ReFarlrs.- 0_. serioea is very rirolific, being the most abund- ant Qorbula. It is recognized by its somewhe.t elongate outline, fine, but strong ooneentric sculpture aiid weaJc, fine radials. The radials are never prominent and may be entirely absent. 3ome of the valves are higher than the tr T)ical form. Ball has placed in synonymy Hie fossil fbrms which Guppy deteDnainel as the recent "3. cubaniana d'Orbigny (1), but ao-oarent- (1). In de la Safrra, -ist. )h s., polit . et natur., f^.e I'lle de 3uba, Koilusques, vol. r„ ^^. '^^'7^ -n . r% fi^s. 51-54, l^^n:^ ly Gup^y reported that species on! " from the Pliocene of Trini- dad and if the Trinidad form i:' sericea that lor>-Ti-^^- ■■<: '^'^■- •'-i fied as sericea is perhaps distinot, beins- larger, with astraipjiter pos- terior margin, more acute poster o-ventral angle, s_ rr post- erior £lo"oe . Qgcurrenee.- IJoper Olip-ocene: ?Gatun formation, Panama (Pro7,Ti and Pilsbr;-, 1911); lov/er I'iocf^-T^: ^.n-.-ripn hrdn^ "'oTrde"., Jamaica fDall, 1898). ? Pliocene ('): Trinidad i Gu -p^ , 1874). Section Bothrocorbula C^abb. COKBUJA (BOTHROaORBUIA) TrxT'T— •, Guppy. Oorbula vlrjinea Guppy, 1866, Quart. Jour. Heol. 3oc. London, vol. ;:2, p. 29,?, pi. 18, fig. 11. 3othrocorbula viminea ( Guppy ) G-abb, 1872, Proc. Acad. ITat. Sci., Philadelphia, for 1872, p. 274, pi. IC, iij-s. 3, Sa. •Bothrocorbula viminea (CruppjO Oabb, 1875, Trans. Am. ^^hilos. Soc, newser., vol. 15, p. 247. Oorbula viriunea Ouppy, Geol.,,;i^f?^^1874, Decade 2, vol. 1, o. 441 ! Che ok 1 is t ) . Jorbula V inline a 5uppy, 1876, Ouart. Jour. C-eol. Soc. London, vol. 32, p. 529. 3orbula (Bothro oorbula ) virainea Gup^oy, Dall ,^ :_c-ib. -ajaier ?ree Inst. Sei., Phila.delphia, vol. 5, pt. 4, p. 850. Jorbiila vi£inea_GupTTy , "BroTjn and Pilsbry, 1911, Proc. Acad. Tat. Sci., Philadelphia, vol. 65, p. ?72. Deserir)tiori.- "Shell thick, transverr.ely oblon?, rounded anteriorly, produced posteriorly , into a -^--- c; or- iJ3.i\ivta~. wij'.- -, rather roimd, concentric ribs; hijjge with a single prominent tooth and a deep orbicular pit in front of it." (Guppy, 10 66). Type locality.- Jamaica. Shell larpe, he'-vj;, moderatelj- inflated, elomate, inequilat- eral; left valve slip'htly smaller; rouj^ded anteriorly, posterior- ly the r;.ar?-in curving gently to the shano oostera-ventrsa anirle; base p-entlj? arcuate, gently enargins-teri. oosteriorly; vmbo low, hroad, place 1 anterior to the rne'iaj.i vertical; limular depress- ions deep, subspherical, larger on the left valve; posterior car- ina sharp, more pronomiced ventrally, cituated near the posterior rnargin, the -oosterior dope narrow and flattened; external sur- face sculptured with coarse concentric rugae, suppressed before the posterior carina is reached, with fine concentric striae in- tercalate" betv-'een the ru^-ae and c "■'"*■':;-■ nous across the posterior slope and the area in front of itj racial sculptirre of fine, ob- scure, distant radial striee between the rugae, the rs-i.ials ab- sei:t on the posterior slope; the cardinal tooth in the right valve strong. Piroensions.- Lenjrth, 17.5 rrn. ; sit., 12 nun.; seraidiam. , 4.8 ram. ?.emar>s.- This s-necies, v,hich v/ell-represented, is reriark:- able for the depth of the lunular deiression, on the bs.sis of v/hich '""-abb erecte'^'- as a set)'rate genus ^.othrocorbnl^,. ^-Iie faint radial scul-iture is often obsolete or even absent. The larc'est v valve has the following dimensions: length, 20 mm.; alt., 15 mm.; cl i am . , 7 rm. Dall has described several closely related S)»cies,- the Ohipola 0. synarmostes (l), the Oak Grove 0. radiatula (2) and the '^aloosahatchie 2* v-'illcoxli {7^ ), all of \fnlch are sinallor and, except for the 1: at, va th a ar.ialler and shallower liinular pit. 0_' he-'aoyraa Bror/n and Pilsbrj' (4), from the Gat^m he^s, (1). loc. cit.. Top. 850-851, pi. 7:6, f i p-s . 12, If', 1898; 19C0. (2). idem, p. 851, pi. 3 6, figs. 1-7.. (3). idem, pp. 851-852, pi. So, fig. 9. (4). Proc. Acad. Liat. 3ci., Philadelphia, tdI. 64, pp. 518-510, pl. 26, firr. 4, 191S. is more elong-ate, with fewer concentric imdulationG, finer ra-Hal striae and vathoat the deep deprr -"-•■'. -^n in front of the imbo,- at least on the right valve. 0?ciirrence»- Upper Oligocene: Santo Dorainp-o (Cabh, 1873; Guppy, 1874, 1876; Dall , 1898); ^ra tun formation, Vamos-vamos, Panama (Dall, 1898); lorjer I'iocene : ^^owden beds, Sov/den, Jamaica (Gupoy, 18 66, 1874; Ball, 1398). oowei o;,' var . 11 . ?astroohaena ovata Sovverb:; vsr. rotrmda Dall, 1808, Trana . ./agiier 7ree liist. 3ci., Philadelphia, vol. 3, pt . 4, p. 825. ? ^-agtrochg cr^ rot nnda "Dall, 1015, ■^ttII. U. 3. I!at . ., no. 30, p. 157, pi. 19, fig. ?. Descrj-Qt ion.^ "Shell r eceinbliiip- the ovata of the -.v-e size, but not attainiiog so large a size as the adult ova '.a, with a more rounde'' posterior end rather shorter gape, the m^o- phore dfcidedly larger, wider, and more ooncpicuonr: . Lon. 7, 1 at . 5.5, diam. 2 . 8 mm . " "The diiferenee "between the recent and the 01i!?ocene shells are so slif^ht, an'"'' the rarE-e of variation in the liv- i., .= oeGi::ieno so .iaj-':ei, i;;iab I feel ;i. willi. , a the distinctive characterc above mentioned seem - , the foo;:il cliell s more than v ■ rlet-^l •• -nk luitil I een a larger numoer o_' ^ ::e 'ji.x'n., . '' ' Jall , T^-pe locality.^ Bowden, Jamaica. Shell er.F,ll, thin, sleu'^er, el o: convex, vi an a promi^^en ; .j. , ^i. anterior end ; e 1 3iirface .'elatl ent incr^ oix^ala and irrej^ul, -^^ l.^^u, u •■'o.i: u.^cr' '.u^j, :.:jj:e r.ronounoed toward the mar^jins; hiii^'e edonbul , ' , 'er ':'. ^e nar'^in, a short m^o-ohore 'rciecti:: •" ''he shell; rausole Bears decidedly,- n:L.e(;u.-x, -i- larger; palMal ainiTC olocciure. Dl?-Bnsions .- Length, 19 cim. ; alt., 7.5 nrn. ; . ...i '. ., ? . 5 m. 3enia.r',:b.- Althonffh the speciniens at hand are rnxich r than the t;;roe material, the^/ are Gnaller, thijriner . ore elon»-sted than the 'r'^.ecent eastand v;est coast 2* ov-^- "■-- --orerbT,' (1) Ihe Pliocene and Recent G. cuneiforr'n.s Spengler ( : (l). Proc. Zool. Soc. London for 18"-1, -o. "1; . .ilu^, , iJe:" "". Oat. Rec. Sh., p. 10, pi. 9, fig. 42, 184r:. (2). ITova Acta Soc. Hafn. vol. S, p. 170, figs. -1-11, l':Ga. and he- vie r, more Islmitl^' rounded posteriorly/, vi th a more a'brupt gape . i^he 'Tampa rotimda is reprecented \>:^' "burrows c " , ':he xiK- ured speci-en heing from the Ohipola marl. Occurrence.- Unper Oli.r^-ocene : ? Tampa ai] , Florida (Dall, ISOO, 1915); Ohipola ■ arl, Florida (Dsll, 1090, 1915). Lower ;"iocene : Bowden hedc, :3ov.-den. Jama:'- , , 191^'). _ 5^^ - 3tiT>erfamil ) j o I,: A J ':. A . Family Pholadirlae. 3 ub f ami 1 j- Jo uar n (-■ "^ i ^\ ?■- e . Genus IMRTISIA Leach ': MAI^TESIA ? sp. indet. The fragoent in the national Miisenin collection to vhich Dall referred (l) as a Xylooha'^'-a may probabl;- "be a T!artesi3 since (1). Drans. "Tafmer Free Inst. Sci., Philadelxihia, vol. Z, pt. 4, . 8S2, 1898. the median sulcus on the shell is -Dronouneed. .his form and the other burror/ers oi douDtful position are mentioned merely in order to complete the faunal list. Occurrence^.- lower Hiocene : "^owden "^e 'S, Bo7;den, Jamaica (Dall, 1898). ■7-1 Genus .i. jjJi-'^iAuA Turton ? ZYLOPHA:'^ ? S1-). inrlet. Teredim ? doubtful species, ^uppy ancl Ball, 1896, ?roc. U. S. ITat. Mus. , vol. 19, -op. .^rV-F.TB. Description.-. "Almost p-lobular, anterior end finelj? closely laminose, posterior area subenual, nearly rmooth, the me'"Tial rrroove feebly rnarke:! ; Galium aoparently complete, siphonal end sli.p-htly e-aping, truncate, the nargins thickened and reflected the dorsal "olates '.vanting, -orobably lost. Alt. 6 nn." "Thic very singular little -oholad is u.iiortunately i perfect, rendering it advisable to await more material before describing it. It as receive'', v/i th the manuscrint name of ITartesia sphaer oidalis, but it is not a i.lartesia aiid per.iCi^a I'lay prove a Tere- dina." (Cxuppy ano. Dall, 1896). RermTjZS^.- To further material is available to supplem-?nt Guppy's single specir.fin, v' . , _ , Xylophar-a. Occurrence .- Tare r I'iocene : Bo'.vden be":s, 3or:den, Jamaica (Giippy and Dall, 1096). - 5^1:0 - Subfamiljr Ueredininae. Genus T^^I^EDiri laraarck. TEHEDIITA BOV/DETIIAJTA Ball. Terecllm bowdenlana Pall, 1898, Trans. I7afmer Free Inst. Soi., Philadelphia,, vol. 3, pt. 4, pp. 822-82,'?, pi. 36, fig. 4. DescriT)tion.- "The specinen obtained is the portion of a tube containing most of the left valve of a Teredim. v/ith very marlred soulpt'u-e. The anterior border is formed bj; a narrow, ir- rep-ularly broken strip of the shelly matter belonfcing to the missing tube. The thin posterior border of the valve is not in- tact, though enough remains to shov^ the character of the sculp- ture. The sculoture of thr anterior part of tlie valve is eom- ■oosed of small, four-sided lozenffes„ separated by sharp, narrow, arcuste grooves in such away as to produce the effect of a nart- in? on the periphery of the valve. '"his o-roovpfl n-nr] faceted sculpture ceases abruptly behind, but the rows of ..acets are •r'on- tinuei as wider longitudinal riblets posteriorly. The ^ombonal reflection is heavy and radially striate; the m-io -'hysis seens to h?.ve been obsolete and its remains appressed to the internal arch or the umbo. The whole is rather thick and solid, and the ant- c-rc-T5osterior length of the frs.gment is cix and a half millimeters. "The very distinct sculpture of this shell instantly dis- ll - tinpuishes it from any other knov.n Teredina." (Dall, 1898), Type localil-;.:.- 3CT;;'den, Jaraaica. riemarlrc . - Thissoeoies &* uob jceii reco~ni.-:e 1 in the collections at hand. .^ OecurreriG^.- lov/er Hioceiie : ^"-^en beds, Bowden, Janmica (Dall, 1898). p; ■^. "^ _ family Teredinidae. Crenue TEI^ED'' ' aeus ? TSR;;jDO sp. Indet. Small fra?:ments oi' calQifiecl tubes, apparently referra'ole to the s-enu:: Teredo, are present in the colleotlons. Dell (1) hc.£ assigned them to T. incrasnata (Gabb) (2), an unpretentious (1), Tra..-. ./a<