478 



MOLLUSKS : GASTEROPODS. 



contains gasteropods which have a shell with an expand- 

 ed lip deeply notched near the canal, and a claw-shaped 

 operculum. They feed on dead animals. Their shells 



Fig. 382. 



Pteroceras lambis, L. One half. Chinese Seas.' 



Fig. 383. 



Fig. 384- 



S trombus pugilis, L. One half. 

 West Indies. 



Aporrhais occidentalis^ Beck. 

 New England. 



are extensively used in the manufacture of shell cameos. 

 The living species are estimated at about eighty, and 

 the fossil at two hundred. Marine. 



* Foreign shells are quite as likely to fall into the hands of American 

 students as those of our own coast. 



