28 
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 each side, all locking into the op¬ 
posite valve. 
1. Cardium acul eat urn. Spinous Cockle. 
Lister , pi. 321. f. 158— Pennant, pi. 53. f. 1— Donovax , 
pi. 6— IVood, 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 5 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. Soicerby , Brit. Mscell. pi. 32. 
The half-grown shell. 
Western coasts, and North Britain, v. v. 
2. Cardium tuberculatum. Tuberchd Cockle. Fig. 12. 
Lister, pi. 328. f. 165—I)o)iovaji, pi. 107- f- 2— Dorset 
Cat. pi. 2. f. 2—IVood, 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 slightly 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 j the posterior side remarkably prominent and 
rounded, 
