78 



POPULAR CONCHOLOGY. 



a very short canal or a notch only ; right lip sharp, and 

 wrinkled within ; left lip with several 

 irregular plaits ; no operculum. Animal, 

 with the foot almost as long as the shell, 

 very thin, and very flatly compressed, the 

 front truncated portion stretched beyond 

 the head, the latter broad and flat ; ten- 

 tacula long and slender, with the eyes camdiaria hbata. 

 outside at the base. — 70 species; also 

 fossil. 



These shells are generally found on the sands of the 

 shores washed by the Indian and African seas, and on the 

 coast of America : they are rare, but not remarkable ; and 

 are usually rough to the touch, and striped. 



Admete. Kroyer. — Shell oval, transparent, brittle, 

 with raised transverse lines ; aperture oval, slightly bor- 

 dered or thickened at the lower part ; columella curved, 

 without plaits, obliquely truncated beneath ; the lip thin 

 and straight. Animal, with the foot large, longer than 

 the shell, broadly truncated before, lancet-shaped behind ; 

 head rounded off, small, without proboscis or tongue 

 membrane ; tentacula long, and thread-like, with the 

 small eyes upon a tubercle at the outer base ; no oper- 

 culum. — 1 species. 



A. crispa is brought from N. America. 



Family 6. — CAS SID A CEA. 



The animals have a large, broad foot, a thick head, with 

 a long stout proboscis ; the tentacula also long and thick, 

 the eyes on a projection at the base ; the tongue has in 

 the middle line one, and on each side three rows of teeth. 

 The shell is of a long, egg-shaped form ; the apertur 



