164 POPULAR CONCHOLOGY. 



extent of the order, be advisable to separate 

 it into those two natural divisions, or into 

 Phytophaga and Zoophaga. 



Division I. — Phytophaga. 



The Phytophaga, or herbivorous Tracheli- 

 pods y have the mouth of the shell entire ; that 

 is, without a notch or channel. Those which 

 are marine procure their food from the sea- 

 weed which they find floating on the surface 

 or at the bottom ; and the land species obtain 

 abundance of nourishment in our gardens and 

 elsewhere. 



They are divided into ten families : — Com 

 macidce, LymnceidcB, Melanida, Per is torn idee ^ Ne- 

 ritidaz, Janthinidce, Macrostomidcz, Plicacidce, 

 Scalaridce, and Turbinidce. 



Family 1. — ColimacidcR* 



The animals of this family are entirely ter- 

 restrial, though usually fond of damp situa- 

 tions. Only two of the genera have permanent 

 opercula, the others forming merely a tem- 



* Les Coli?nacees, Lamarck. 



