﻿CtASTIM)CH.ENA. 



Pi.Aii; III. 



Species 12. (Mus. Brit.) 



GastrocHjEna mytiloide.^. Gas. fesin compressd, e/ii- 

 dminide jJavescenti itidufd, ohlmigd, forhiosd; lattre 

 aiifico ante umbmies producto, acuminata ; lafrrc 

 poatlco ante aream di'pre-sso, area posited contahu- 

 latd, distanftr >iidcatd ; area dormli aiignntd. 



The >n"nLUS-sHAPED Gastboch.^na. Shell com- 

 pressed, covered with a yellowish epidermis, 

 oblong, tortuous ; anterior side produced in front 

 of the umbones, acuminated ; posterior side de- 

 pressed in front of ihc area, posterior area con- 

 tabulated, distantly grooved : dorsal area narrow. 



Lamarck. Anim. s. Vert. 



]I„h. ? 



Resembling (laytrorlicna rustratu, but with dorsal 

 area very naiTOw, and posterior flattened area 

 grooved at distant intervals. 



Species 13. (.Mus. Brit.) 



GASTEOCnj:XA RUCrLOSA. r.'ii.s-. fr.-<ti! dipi-e.-sd, iihliqitr 

 cuneiformi, elongatd, antkhanijustii.^i'h'irindiitatd, 

 2)osf ice concent rice distanter linit^l ,• liinlu. jiit'iVun-ri. 



The wrinkled Gastrocu.ena. Shell depressed, ob- 

 liquely cuneiform, lengthened, narrow in front, 

 rather acuminated, posteriorly concentrically 

 distantly ridged ; gape moderate. 



SowEEBT. Proc. Zool. Soc. 18:34-. p. 22. 



Bah. Gallapagos Islands. 



Species 14. (Mus. Brit) 



GaSTROCH.ENA LAMELLOSA. Gas. /'>■/"' r,v,l/i,; <.<•!, ,ni- 

 gustd, elongatd, antice. attcmt'th!, nciniiiinili!, jioit. 

 tice concentrici lamitiis rrehrls liratd; hialu 

 ventrali angustu, ehiigato. 



The lamellated Gastroi'H.esa. Shell compres.sed, 

 naiTOW, elongated, anteriorlv attenuated, acu- 

 minated, posteriorly concentrically ridged with 

 frequent lamina-, venti-.-il hiiitus inirinw, Ioiil;-. 



Deshates. Proc. Zool. Soc. 1^"4. ]>. -Vl^. 



Hal. Isl. Zebu, Philippines. 



Species \r,. (Mus. Brit.) 



Gastrocm.kna 

 ntrini/iu' i 



6'ff.s-. te.^td ehnigato-,cat,i 



d;„ 



aciimiiiatd, t'-nuifer denai; siriafd 

 leviier depressd; hiatnlaiisslino,feiv ad teriuiiiion 

 posticum caJvariiDi exteuso. 



The liiGANTic Gastkoch.t.na. Shell elongated-ovate, 

 acuminated at each end, finely densely striated, 

 slightly depressed in the middle; hiatus very 

 broad, extending nearly to the end of the 



Dkshayes. MS. in Cuming's Collection. 



l/„h. ? 



This large species is named from specimens 

 the British JIuseuni. The valves are more r< 

 ovate, althongh acuminated at the end and 

 ened, than tliose of G. cmieiformiy. 



dves. 



ilarly 

 ntrth- 



Species 16. (Mus. Brit.) 



Gasti;uch.hna o\j 



orntd, ..,j;,l,i 



nhli 



■dlinu hm.j.n 



7'« '"■ 



,i;dr 



lr,W >^t,-;,ila ; hinta i;j,ttrall subrutiiud,,. 



The ovate Gastroch.ena. Shell very ventricose, 

 short, ovate, solid, anteriorly and as far as the 

 middle concentrically striated, past the middle 

 smooth, near the dorsal margin obliquely tumid, 

 and strongly concentrically striated ; ventral 

 hiatus rather round. 



Soweert. Proc. Zool. Soc. l^Si, j). 21. 



Huh. Panama. 



Species 17. (Mns. Brit.) 



GASTnOCH.EXA PUPIXA. Tr't/v. tr.-it,; i-(llnij;.< 



fubd h:r'vi,angiistr htilbifuiini, in xfct'cmf^ 

 ifiumiarticidatd, per latiis ud tr>:t,i.< mUnr,: 

 The pupina Gastroch.'Exa. Shell with vul 

 known ; tube smooth, narrowly bulb- 

 ciuasi-articulated in five sections, atta- 

 the side to .shells. 



es un- 

 haped, 

 .ed by 



