88 



POPULAR CONCHOLOGY. 



thick brown epidermis, ligament external, three 

 cardinal teeth, and generally one lateral tooth 



in each valve, bosses turned on one side. 

 Animal, foot large. — 1 species recent, and 6 

 fossil. 



Chiefly fossil, with one recent species, Cy- 

 prina Islandica, which is found in the North- 

 ern Seas. These shells are often very large. 



47. Astahte (Sowerby). — Shell equivalve, 

 inequilateral, nearly or- 

 bicular, but somewhat 

 transverse ; two di- 

 verging teeth in the right 

 valve, with one distinct, 

 and one obsolete tooth 

 in the left, covered with a brown epidermis 



