136 C O N C H O L O G Y. 



It will be difficult to fix the limits where 

 one clafs ends, and another begins. But, 

 by keeping clofe in view the natural pro- 

 ceffion, it feems praflicable to form a bet- 

 ter fyftem than any yet propofed. 



The enumeration of the Univalves is as 

 follows : 



Divifion I. Univalves. 



Part I. Simple Univalves, or Univalves 

 not turbinated, or little, if at all, fpiral. 

 This part contains four families : viz. i. 

 The Limpets. 2. The Aures Marinae, which 

 are (lightly fpiral. 3. The Vermiculi or 

 Worm Shells : and, 4. The Dentalia. 



Family i. Limpets. Patellae. 



This fiimily derives its Latin name from 

 its refemblance to a little plate ; like this 

 utenfil, the Limpets are for the mofl part 

 round, or oval, or approaching thereto ; 



the 



