30 CARDIUM. COCKLE. 



and longitudinally lance-shaped, like the upper ones of the 

 full grown shell. 



Variety. With the spines somewhat spatulate or flat- 

 tened, and rather longer and more distant. We have in our 

 cabinet specimens, where some of the spines are lanceolate, 

 some of them pointed and curved, and others spatulate, 

 thick, and very obtuse. 



Cardium Spatula. Laskey, JVern. Soc. p. 381. 



Common on most sandy coasts, v. v. 



4. Cardium edule. Common Cockle. 



Lister, 334. f . 1 7 1 Pennant, pi. 53. f. 3 Da Costa, pi. 1 1 . 

 f. 1 Dorset Cat. pi. 11. f. 1 Donovan, pi. 124 Wood, 

 pi. 55. f. 4. 



Shell convex, a little produced on one side, with about 

 twenty-six ribs, which are flattened in the middle and a 

 little rounded at the sides, mostly marked w th concentric 

 rings and ridges, and somewhat roughened near the cir- 

 cumference with obsolete recurved scales, which are 

 stronger on the shorter side : color white or yellowish- 

 white with often a blueish cast, generally dark red at the 

 elongated end and towards the hinge ; inside white, with a 

 large dark red blotch on the produced side. The very young 

 are globular, semitransparent, and clear white. Length 

 about an inch and a half j breadth a little more. 



Variety A. Cardium rusticuni. Lister, pi. 329. f. 166. 

 Donovan, pi. 124. f. 2. Wood, pi. 55. f. 2, 3. 



Shell larger, with about eighteen or twenty ribs, which 

 are more elevated and rugged in the interstices, of a fer- 

 ruginous or livid color, with often narrow chocolate- 

 brown zones. 



Variety}^. Very much elongated and flattened on one side. 



Variety C. Globular, with all the ribs rounded, rather 

 polished, of a pale reddish white, with a rose-colored 

 tinge about the projection below the hinge on the poste- 

 rior side, and about half the size. 



These two last are found imbedded in blue clay at the 

 mouths of rivers, in Dublin bay : but all the varieties may 

 be distinguished by the obscure transverse scales . 



Common on all coasts, v. v. 



