CARDIUM. 219 



cate longitudinal ribs, four or five of which, on the ante- 

 rior part of the shell, are finely tuberculated. The in- 

 side is white, marked with light purple, under the sum- 

 mit : the margin is serrated ; the hinge has four teeth in 

 each valve. Length an inch and an eighth ; breadth an 

 inch. 



Country unknown. 



From its shape and colour, this shell might be taken 

 for the young of the C. magnum; but that it is decidedly 

 different from that species, may be inferred from the 

 number and appearance of the ribs. It is well figured 

 in the Encyclop&die MSthodique; but the specimen in 

 that work is larger than ours, being an inch and three 

 quarters long, and an inch and a half broad. 



TOOTHED COCKLE. 

 PI. 53./. i, 2. Linnean Society's Cabinet. 



18. Cardium ringens. C. testa rotunda, ventricosa, alba; marginis den- 



tibus profundis, anterioris roseis. Linn. Gmel, p. 3254. 

 Shell round, ventricose, white ; margin deeply toothed, and rosy, on the 



fore part. 

 Testa rotundata, longitudinaliter costata, margine antico profunde ser- 



rata, hiante. Brug. Encyc. Meth. Hist. Nat. 6. p. 225. 

 List. Conch, pi. 330. f. 167. Petiver Mus. p. 36. n°. 836. Knorr 



Vergn. 4. pi. 14. f. 3. Favanne Conch, pi. 52. f. F. Chem. Conch. 6. 



pi. 16. f. 170. Encyclop. Method, pi. 296. f. 3. 



A strong shell, with the eight anterior ribs deeply cut 

 like the teeth of a saw ; the colour is white, except a 

 rosy blush on the teeth, and, sometimes, on the apex of 

 the shell. The inside is white, with a tint of pale rose 

 colour on the anterior margin ; there are four teeth in 

 each valve ; two primary teeth, the largest of which is 



