629 



rabescente maculata et radiata; latere antico brevi, rotundato, 

 postico rotundato ; lunula elongata, distincta, vix tumida ; liga- 

 mento subelongato ; margine dorsab subelevato. 



Shell oval, rather compressed, smooth, fawn-coloured, with 

 brown rays and spots ; anterior side short, rounded ; lunule 

 rather long, defined, and raised ; posterior side rounded, elevated 

 at the dorsal margin. 



England, and the Mediterranean. Mr. Cuming's specimens 

 are from Mazatlan. 



60. Cytheiuea maculata (pi. cxxxi. f. 93, 94, 97), Linnaus, 

 p. 1132. 



Cyth. testa C. Chioni simili, sed antice elongatiuscula, prope 

 lunulam magis excavata, postice subacuminata, subangulata; 

 lunula tumida. 



Shell generally flatter and less rounded than C. Chione, with 

 the dorsal margin and lunule tumid. The colouring is arranged 

 in square spots, disposed angularly, and partly collected into two 

 central rays ; in one variety these spots are purple. 



South America. The very acuminated variety, fig. 93, 94, is 

 from Australia, in Mr. Cuming's collection. The posterior 

 elongation does not commence till the shell has attained a con- 

 siderable growth. 



61. CythebjBA unicolor (pi. cxxxi. f. 90, 91), Sowerbg, 

 sen., Pro. Zool. Soc. 1835. p. 23. 



" Cyth. testa ovato-subcordiformi, crassiuscula, brunnescente, 

 lsevi, polita; latere antico posticoque concentrice sulcatis, sulcis 

 medio obsoletis ; latere postico longiore, versus partem ventralem 

 subacuminato ; margine ventrali lsevi, intus purpurascente." 



Shell heart-shaped, rather thick, whitish or brown, smooth, 

 grooved at the sides, plain in the middle ; the hinder side longest, 

 angulated, and near the ventral margin rather acuminated. 



Xippixapi, West Columbia ; coarse sand, at 6 fathoms. Cuming. 



61.* Cyther/ea squalida (pi. cxxxi. f. 87, 88, 89), Sowerbg, 

 Pro. Zool. Soc. 1835. p. 23. Var. C. binuliata, Beeche/s Yoyage. 



"Cyth. testa ovato-subcordata, crassiuscula, rubente-albicante 

 radiata ; latere postico longiore, subacuminato ; costellis nume- 

 rosis, concentricis, obtusis, concinnis, confertis." 



Shell more angulated posteriorly than C. maculata, and with the 

 lunule and dorsal margin less tumid. Although named from the 



