621 



sed postice valide angulata; margine ventrali prope angulum 

 paululum contracto. 



Shell almost trigonal ; the posterior side decidedly angular, and 

 the ventral margin very slightly contracted near the posterior 

 angle. The typical variety is marked with fluctuating angular 

 lines arranged in bands. 



Our specimens are both from China, in Mr. Cuming's collection. 



30. Cyther^a impudica (pi. cxxix. f. 55, 56, 57, 58). 

 Venus, Chermt,. f. 347, 348, 350 ; Lamarck, Cyth. no. 3. Var. 

 C. castanea, Lamarck, no. 4. 



Cyth. testa C. meretrici simili, sed magis ventricosa, soUda, et 

 rotundata. 



Shell much more ventricose, thick, and rounded, than C. mere- 

 trix. One variety is of a pale pink-buff (f. 55); another, the 

 same radiated and suffused with grey ; a third has two brown rays ; 

 and a fourth, C. castanea, Lamarck, is chestnut all over. 



Fig. 58, Singapore; Mus. Cuming. Mg. 56, 57, Philippines; 

 Cuming. Fig. 55, Mr. Sowerby's collection. 



31. Cythee^a casta (pi. cxxix. f. 43, 44, 46), Gmelin. 

 Var. C. brunnea, Chemn."^ 



Cyth. testa C. meretrici simili, sed soHdiore ; C. impudica simili, 

 sed rectiuscula, suba^quilatera ; latere postico subquadrato ; testa 

 pallida, nonnunquam fascia aurantiaca unica prope marginem 

 cincta ; epidermide rufescente. 



Shell more straight and square, less oblique and rounded, than 

 C. impudica ; colour pale, witJi a reddish epidermis. There is one 

 variety from Ceylon, \vhich always has an orange band near the 

 ventral margin, leaving the remaining space white : Mr. Sowerby 

 possesses specimens of this. 



32. CytheRjEA ovum (pi. cxxix. f. 45), Hanley, Species of 

 Shells. 



Cyth. testa C. castcB simili, sed magis elongata et ovata. 

 Much more elongated and oval than C. casta. 



33. CYTHERiEA LYEATA (pi. cxxix. f. 61), Sowerli/,jun. 



Cyth. testa ovali-subtrigona, crassa, ventricosa, fulva grisescente 

 concentrice subundatim sulcata ; latere postico subangulato, fusco ; 

 lunula vix distincta. 



This beautiful shell takes the form as the group just concluded. 



