DESCRIPTION. 
125 
casually darker than the rest. Lateral teeth elon- 
gated, inserted; primary ones smalL 
Inhabits the British coast. 
Fig. 5, Hi NGE oFCardium echinatum. 
Fig. 6 . Caedium edule. 
Shell antiquated, with 20 — 30 rounded ribs, 
obsoletely imbricate. 
Lister Conch. T. 333, F, 170. T, 334. F, 171. 
Specimen pale brown, cinereous towards the 
margin ; a dark brown and tawny spot upon the 
internal cavity of the anterior slope. 
This shell, which is the common cockle of the 
market, is found in great numbers on the British 
coast, buried in the sand at no great distance from 
the surface. 
Fig, 7, C. Cardissa, 
Shell cordate, valves compressed, dentato-cari- 
nate ; beaks approximate. 
Lister Conch. Tab. 318. 
Specimen white ; equivalve ; ribs oblique ; beaks 
slightly crossing each other; cordate impression 
