DESCRIPTION. 137 



Fig. 5. Hinge of Cardium echinahim. 



Fig. 6. Cardutm cdule. 



Shell antiquated, with 20 — 30 louiuled rib^, ob- 

 soletely imbricate. 



Lister Conch, t. 333. f. 170 t. 334. f. 171. 



Specimen pale brown, cinereous towards the 

 margin ; a dark brown and tawny spot uj^on 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 frora 

 the surface. 



Fig. 7' C. cardissn. 



Shell cordate, valves compressed, dentato-cari- 

 nate ; beaks approximate. 



Lister Conch, tab. 3 IS. 



Specimen white ; equivalve ; ribs oblique ; beaks 

 slightly crossing each other ; cordate impression 

 on the area well defined ; anterior side nearly flal, 

 posterior one convex except towards the margin 



inhabits the Indian Ocean. 



