622 



but is characterized by waved, deep- cut, concentric ridges. The 

 hinder side is marked with deep brown. 



Jinigaran, Island of Negroes, Philippines. Cmning. 



34. CYTHERiEA ARGENTINA (pi. cxxix. f. 62), Sowerbi/, sen., 

 Pro. Zool. Soc. 1835. p. 46. 



Cyth. testa subtrigona, alba, subsequilaterali ; latere antico 

 paulb breviore, postico subacuminato j margine dorsali postico 

 rectinsculo, declivi, ventrali rotundato ; epidermide tend, cornea, 

 extiis velutina, alba, quasi argentata, induta. 



Shell subtrigonal, white, subequilateral ; the anterior side a 

 Httle the shorter, the hinder side rather acuminated ; the ventral 

 margin rounded; epidermis thin, pale-green, with a velvety, 

 silver-like coating over it. 



Gulf of Nocoiya, Central America ; sand-banks at low water. 

 Cuming. 



35. Cyther^ea nobilis (pi. cxxx. f. 68), Beeve, Pro. Zool. 

 Soc. 1849. 



Cyth. testa crassa, alba, rotundata, concentrice subundatim 

 costata, ventricosa; latere antico brevi, rotundato, latere postico 

 unisulcato; margine postico dorsali et Hgamento elongatis; lu- 

 nula distincta, excavata ; uinbonibus magnis. 



A fine, large, heavy, ribbed, rounded, white shell, with hinder 

 dorsal margin and ligament high and long ; lunule excavated, and 

 anterior side short ; a depressed ridge at the posterior side. 



36. Cytheu^a purpurata (pi. cxxx. f. 67), Lamarch, Anim. 

 s. vert. Cyth. no. 9. C. lubrica, Broderij), Zool. Proc. 1835. 



Cyth. testa nitente, crassa, rotundata, subcompressa, purpurea, 

 intiis alba, sulcis inoequalibus cincta, postice obscure angulata; 

 margine dorsali subexcavata ; lunula impressa. 



Shell thick, shining, rounded, purple, white within, rather com- 

 pressed, girt with unequal, distant grooves ; dorsal margin rather 

 hollow ; lunule impressed. 



Puerto Portrero, Central America. Cuming. 



37. Cyther^a umbonella (pi. cxxx. f. 63, 64, 65, 66), 

 Lamarck, Anim. s. vert. Ci/th. no. 55. Var. C. nivea, Ranley, 

 Sp. of SheUs, p. 97. 



Cyth. testa crassa, ventricosa, nitente, ovali, insequilatera, pur- 



