23 CARDIUM. COCKLE. 



CARDIUM. COCKLE. 



Shell with two equal convex valves, mostly rib- 

 bed longitudinally, and toothed round the "mar- 

 gins: hinge with two primary teeth, and a larger 

 remote one on eaeh side, all locking into the op- 

 posite valve. 



1. Cardium aculeatum. Spinous Cockle. 



Lister, pi. 321. f. \5S-Pennant, pi. 53. f. IDonovan, 

 pi. 6 JFood, pi. 51. f. 1. 



Shell very convex, thin and light in proportion to its 

 size, with about twenty-one ribs which have a groove down 

 the middle of each, produced, rather straight, and a little 

 angular on the cartilage side, clothed with pointed and 

 straight or somewhat curved spines which increase in size 

 towards the flattened margin ; the anterior side rounded 

 and covered with flattened tubercles which enlarge towards 

 the margin : color yellowish-brown, with darker bands 

 and blotches, and sometimes pale or whitish markings ; 

 inside white, glossy, often tinged with purple or flesh-co- 

 lor, grooved in the middle up to the very hinge : length, 

 when full grown, nearly four inches ; circumference about 

 eleven. 



Cardium spinosum. Sowerby, Brit. Miscell. pi. 32. 



The half-grown shell. 



Western coasts, and North Britain, v. v. 



2. Cardium tuberculatum. Tuberded Cockle. Fig. 12. 

 Lister, pi. 328. f. 165 -Donovan, pi. 107. f. 2 Dorset 



Cat. pi. 2. f. 2 Wood, pi. 50. f. 1, 2. 



Shell very convex, thick, ponderous, and rounded, with 

 about twenty-two very prominent and rounded ribs, which 

 are not grooved down the middle, covered with obtuse tu- 

 bercles which form very rugged wrinkles on the posterior 

 side, and roughly striate in the interstices; the anterior side 

 elongated, flattened, and sligh.ly prominent in the middle, 

 presenting a broad heart-shaped front, with about seven 

 cord-like ribs on each side, and a little gaping below the 

 cartilage - y the posterior side remarkably prominent and 



rounded, 



