﻿C Y K E X A. 



Plate XVJII. 



Species 101. (Mus. Bnt.; 



Cyrena ovalis. Cyr. testa tenui, ovata, suhcpquilatcrali, 

 mguhtrilai; dctist; Uyn'it, epidcrmide olivaceo- 

 nigriciinti, niicnti Indnfii, infiis purjnired; latere 

 anfico breviihculi, vlnndo; latere postico late 

 ^uhlrunrato ; urnhniiil/ns elirviitis, purpureo per- 

 peiidicHhiriter faxcint':'. 



The ovat. Cyuexa. Shell thin, ovate, subequilateral, 

 regularly ami very closely ridged, covered with 

 an olive-blackish, shiny epidermis, purple with- 

 in : anterior side the shorter, rounded ; posterior 

 side broadly subtrimcated ; nmboes raised, per- 

 pendicularly banded with purple. 



Pkime. Journal de Conchyliologie, PI. 2, f. 6. 



Hah. ? 



The ridges in this corbicula are more fine, close, 



and continuous than either of the two similarly shaped 



species. 



Species 102. (]\[us. lirit.) 



Cyrena Fi.oriuan-a. Cyr. te.-td hreri, altd, crassd, 

 tumidinsimd, inaiquilafrralHer suhtrigond, la'vi- 

 gatd, snhtns epidermidem rosed, iiiti'is earned, 

 epidi',-iiiid>'j!iirido-fidvd, rastaneo inaculatd; latere 

 p(i.<liro drrliri miijidoto, ad angulum fere cariiiato, 

 i»frd (irniiiiii'ti!.! : nmhimibus tumidk, elavati.'! ; 

 latere autka hrevi, der.Uvi 



The Florida Cyrena. Shell short, high, thick, very 

 tumid, inequilaterally trigonal, smooth, pinky 

 under the epidermis, flesh-coloured within ; 

 epidermis yellowish fawn, spotted with chestnut ; 

 posterior side sloped, almost keeled at the angle, 

 a'-'uminated below ; umboes tumid, raised ; an- 

 terior side short, sloped. 



Coxrad. Freshwater Shells of United States. 



Hah. Florida. 



Species 103. (Mas. Brit.) 

 Cykena isocardioides. Cyr. te.9td hrevi, althsimd, 

 tenui, tumidissimd, superne suhtrigond, epidermide 

 Icevigatd, tenui, corned indutd, iiitus ad cardinem 

 et suhtus umbones piirpured ; latere antico hrevis- 

 simo, suhtus iimhones exeavato, versus medium 

 valde infiato ; umhonibus subdistantibus, latere 



postico subrostrato, angvlato, trnncaio, iiuiri/iiir 

 ventrali valde convexo. 



The IsocARDiA-LiKE Cyrena. Shell short, very liigh. 

 thin, very tumid, triangular at the upper part, 

 covered with a smooth, thin, horny epidermis, 

 purple inside at the hinge, and under the umboes ; 

 anterior side very short, excavated beneath the 

 umboes ; umboes a little distant, posterior side 

 rather beaked, angular, truncated ; venti'al mar- 

 gin very convex. 



Deshayes ? MS. Cum. Col. 



Hah. ■ ? 



Species 101. (Mas. Brit.) 



Cyrena soli ha. Cyr. tesid cra.«r?, magna, hrevi ter 

 suhrliiiinboided, tum.dissimd, epidermide toHuis. 

 simd indutd, aniice leuiter rugatd ; latere antico 

 brevissimo, umhonibus fere terminalibus ; latere 

 postico producto, obtusli angulato; margiiie lalem- 

 dorsali elongate, arcuato ; margine veidrali con- 

 vexo, versus angulum posticum sursnin acclivi. 



The solid Cyrena. Shell thick, large, shortly sub- 

 rhomboidal, verj- tumid, covered with a very thin 

 epidermis, anteriorly lightly wrinkled ; auterioi' 

 side very short, umboes nearly terminal, posterior 

 side produced, obtusely angular ; dorsal margin 

 lengthened, arched ; ventral margin convex, 

 sloped up towards the posterior angle. 



Deshayes ? MS. Cnm. Coll. 



Hah. Australia. 



Species lli.j. (Mus. Brit.) 



Cyrena Jukesii. Cyr. testa ovald,compressd, Imvigatd, 

 cpideniiide fused, crenulatim striata indutd; latere 

 aiiticn hrevi; latere postico producto, margine 

 dorsali arcnatim decliri. 



JuKEs's Cyrena. Shell ovate, compressed, smooth, 

 covered with a brown e]iidermis with crenulated 

 striae ; anterior side short ; posteiior side pro- 

 duced, dorsal margin slightly arched, sloped 

 downwards. 



Deshayes. Proc. Zool. Soc. 1854, p. 19. 



Hab. Port Essington. 



