CARDIUM. 237 



longitudinal ribs, separated by narrow grooves ; the mar- 

 gin is crenated. The inside is white, and grooved, and 

 the lateral teeth of the hinge are strong. 



Inhabits the Indian ocean, and the Nicobar islands. 



The only specimen of this shell in the Linnaean 

 collection is a worn single valve. In its live state, it is 

 described by Chemnitz as of a white colour, spotted 

 and banded with pale yellow, and armed with minute 

 points, which seem hollow, and feel rough when the 

 finger is passed over the shell. Our shell appears to 

 be the same, excepting colour and size, as that of 

 Chemnitz ; but Born's specimen differs from both, the 

 hinge in his figure being nearer to the middle of the 

 shell. 



FLEXUOUS COCKLE. 



42. Cardium flexuosum. C. testa rotundata, fusca; costis jlexuosis, 

 sulcis rugosis. Linn. Gmel. p. 3255. 



Shell rounded, brown, ribs flexuous, grooves wrinkled. 

 List. Conch, pi. 343. f. 180. 



An obscure species, about an inch and three quarters 

 long. 



DECUSSATED COCKLE. 



43. Cardium cancellatum. C. testa subruhra, tenui, rotundata, decus- 

 satim striata. Linn. Gmel. p. 3256. 



Shell reddish, thin, rounded, with decussated striae. 

 Gnalt. Test. pi. 83. f. B. 



A small species described only by Chemnitz. Not 

 more than half an inch broad. 



