﻿C Y R E N A. 



Plate XIX. 



Species 108. (Mus. Sowerby.) 

 Cykksa DOSACIFORMIS. Ct/r. testd parvd, teimisshne 

 Uratd, trigond, valde iiicequilaterali ; margine 

 dorsaU ntrinque valda decUvi, area irnqrured, utrd- 

 que valvd senvilunatd; latere antico hreviusculo, 

 (leclivi, subacnminato, latere po.itico attenuati)ii 

 producfo, ad terviinum acuminafo. 

 Thk donax-shaped Cvrena. Shell small, very finely 

 ridged, trigonal, very inequilateral ; dorsal mar- 

 gin mncli sloped on each side, with a semilunar 

 area of purple on each valve ; anterior side 

 rather short, sloped, rather acuminated, posterior 

 side taperingly produced, acuminated at the 

 end. 



SoWEKIiY. 

 Hah. Florida. 



This species belongs to the Corhicida group in the 

 cliiiracter of the hinge. 



Species 100. (Mus. Brit.) 



Cyre.va anomala. Ctjr. ti'std timiussimd, itijlald, altd, 

 sVibtrigond, epidermide tenui, pallida subviridi, 

 indtdd, intih ad cardineni et infra umlones pur- 

 pured ; latere antico inflatd, rotunda, hrevi ; um- 

 bonihus inflatis, roiundis, margine ventrali valde 

 convexo ; latere postico produdo, acute rostrato, 

 attenuato. 



The ANOJl-ilLOUS Ctrena. Shell very thin, inflated, 

 high, subtrigonal, covered with a thin greenish 

 epidermis, purple within on the hinge and under 

 the umboes ; antei-ior side inflated, rounded, 

 short ; umboes inflated, rounded, ventral margin 

 very convex ; posterior side produced, sharply 

 beaked, attenuated. 



Deshayes. Proc. Zool. Soc. 1854, p. 51. 



3ab. Bay of Caraccas. 



Veiy full and globular in front, compressed and 



narrowed to a point at'the back. 



Species 110. (ilus. Sowerby, odd valves.) 



Cyeena Mexicasa. Cijr. testa ovafd, injlatd, tenui, 

 epidermide obscuii fused indiitd, intiis jiaUidissime 



citrnrd, ad talus posticum purpurea; latere 

 antico brcvissimo ; medio injlato ; latere poslico 

 prodncto, margine latero-dorsali declivi, margine 

 terminali obtuso, obttisissime angulato. 



The Mexican Cyrena. Shell ovate, inflated, thin, 

 covered with a dull brown epidermis, very |)al(' 

 flesh-colour within, purple at the posterior side ; 

 anterior very short, middle inflated ; posterior 

 side produced, dor.so-lateral margin sloped, ter- 

 minal margin obtuse, very obtusely angular. 



Broderip and Sowerhy. Zool. .Journ. V. 5. 



Hab. Mazatlan, Me.xico. 



Species 111. (ilus. Sowerby.) 



Cyrena Ceylanica. Cyr. testd magna, solidd, snldn- 

 gond, snbcompressd, altd, suhequllaterali, epid, r- 

 mide tenui, jlavidd, fimbriatim striata indutd ,■ 

 latere postico obtuse biangulato, ante angalnnr 

 aiiiicwm subconcavd, post angulum posticum coni- 

 planatd, valde declivi ; latere antico brrviiiscnio, 

 margine latero-dorsali complanato, decliri. 



The Ceylon Cyrena. Shell large, solid, subtrigonal, 

 subcompressed, high, subequilateral, covered 

 with a thin, yellowish epidermis, with fringed 

 strife ; posterior side obtusely two-angled, rather 

 concave in front of the anterior angle ; flattened, 

 much sloped behind the posterior angle ; anterior 

 side rather short, latero-dorsal margin flattened, 

 sloped. 



Chemnitz. (Venus) Marl, and Chemn. 



Venus coaxana. Gmel. 



Cyrena Zeylanica. Lamarck. 



Ci/rciia pallida. Deshayes. 



Hah. Ceylon. 



Species 112. (Mus. Brit.) 

 Cyuexa cO-MriA. Cyr. testa ovato-oblungd, depressd, 

 tumidd, crassd, Iwvigatd, epidermide pallide Jla- 

 vidd nitenti indutd ; latere antico brevi ; laterr 

 postico prodwln, suliattenuato, angulato, ante 

 anipduni s'dfi'in pd sx,,, niargine dorsali declivi, 

 maniiiie teriuiiinli I'm .njiilato, truncato. 

 The spruce Cyue.na. Shell ovate-oblong, depressed, 



