CARDIUM. 227 



ICELAND COCKLE. 



26. Cardium Icelandicum. C. testa sulcata, costis ad triginta sex, tri- 



quetris, Icevibus. Linn. Gmel. p. 3252. 

 Shell grooved, with about thirty-six smooth, triangular ribs. 

 Testa gibba, longitudinaliter sulcata, costis subtriquetris, acutis, ano 



obsolete cordato. Brug. Encyc. Meth. Hist. Nat. 6. p. 222. 

 Chem. Conch. 6. pi. 19. f. 195, 196. Encyclop. Method, pi. 300. f. 8. 



A strong shell, of a whitish, or yellowish-brown 

 colour, with from thirty to thirty-six triangular ribs ; 

 the grooves are deep, and ridged transversely, especially 

 towards the external edges ; the inside is grooved, with 

 a crenated margin. Length two inches ; breadth about 

 the same. 



Inhabits the coast of Iceland, and was discovered by 

 Chemnitz. 



GREENLAND COCKLE. 



27. Cardium Groenlandicum. C. testa antiquata, glabra, tenui, murina, 

 lineis angulatis ferrugineis picta ; mar gine glabra, striis longitudina- 

 libus obsoletis. Linn. Gmel. p. 3252. 



Shell antiquated, smooth, .JhM> and mouse-coloured, with angular fer- 

 ruginous lines; margin smooth, striae longitudinal, and obsolete. 



Testa cordata, Icevi, grisea, decussata, striis lateralibus obsoletis. Brug. 

 Encyc. Meth. Hist. Nat. 6. p. 222. 



Chem. Conch. 6. pi. 19. f. 198. Encyclop. Method, pi. 300. f. 7. 



This species, as Chemnitz observes, has externally 

 the appearance of a Venus, and might be taken for a 

 shell of that genus, but for the hinge, which has four 

 teeth, the same as other cockles ; bat the two primary 

 teeth are very small. The surface is smooth, and marked 

 with very fine, distant, longitudinal striae, diverging 



