﻿C Y E E N A. 



Plate III. 



Species 7. (Mus. Brit.) 



Ctrena insignis. C<jr. testa elungalo-subqnadratd, 

 snlcompresm, antice rugis elevatis, undulatis, non- 

 nidlLs bifurcatis Urata, postice Icevigatd; latere 

 aiitico hrevi, rolundo ; latere postico subquadrato, 

 urea dorsali impressd ohllqtie radiato ; imibonibus 

 di-pri^ssis ; manjine ventraJ! rcciiusculo. 



The wonderful Cyeena. Shell elongated-sub- 

 quadrate, rather compressed, anteriorly ridged 

 with rai.sed, undulating, some of them bifur- 

 cated wrinkles, posteriorly smooth ; anterior side 

 short, round ; posterior side rather square, 

 obliquely rayed with a dorsal area ; umboes 

 depre.ssed, ventral margin rather straight. 



Deshates. Proc. Zool. Soc. 1854, p. 18. 



Hab. Philippines. 



The wrinkles on the anterior surface of this shell 



are very remarkable. 



Species 8. (Fig. a, b, Mus. Brit.) 

 Cyrena hinor. Cijr. testa oeato-sub rotunda, depre^Ka, 

 cmnpressd, nubviridi-stramined, medio albo bi- 

 radiato, Iwvigato ; intus viride piirpureo radiato ; 

 latere aniico breviter lirato, brevi, valde declivi ; 

 latere postico latiori ; umbonibus obtusis ; margine 

 dorsali depresso ; cardino angusto, dente laterali 

 autico breviiisculo. 

 Thy smallek Cyrena. Shell ovate-roundish, de- 

 pressed, compressed, greenish straw, with two 



white rays, smooth ; rayed with bright purpli^ 

 ■\vithin ; anterior side shortly ridged, shoi'i, 

 much sloped ; posterior side wider ; nmboes 

 obtuse ; dorsal margin depressed ; hinge narrow, 

 lateral anterior tooth rather short. 

 Prime. MS. Mus. Brit, 

 Eab. — 



This little shell being rayed within and without, 

 and being more depressed at the dorsal margin than 

 most of tlie group to which it belongs, may show 

 it to be a distinct species, rather than the young of 

 some other. 



secies 9. (Mus. Brit.) 



Cyrena unioniformis. Cyr. testa crassd, oblmigd, rcni- 

 formi, subarcuatd, epidermide nigra, rugatd iit- 

 dutd ; latere antico brevi, margine dorsali declni; 

 umbotiibus parvis incurvif, depressis, latere postico 

 producto, margine dorsali arcitato, margine venirali 

 excavato ; ligamento maximo. 



The unio-shaped Cyrena. Shell thick, oblong, 

 kidney-shaped, rather arched, covered with a 

 black, rough epidermis ; anterior side short, 

 dorsal margin sloped ; umboes small, incurved, 

 depressed ; posterior side produced, dorsal 

 margin arched ; ventral margin excavated ; liga- 

 ment very large. 



Prime. Proc. Zool. Soc. 1860, p. 319. 



Eah. ? 



