OF CONCHOLOGY. 11 



to enable him to discriminate the dif- 

 ference. But, indeed, this is often a 

 difficult matter, even to those who have 

 studied the science for many years. 



In almost all the cypraea, there is 

 considerable difficulty in distinguish- 

 ing them from the voluta, in their 

 young state. The denticulated lip 

 being the last part of the shell which 

 the animal forms. The strombus ge- 

 nus want the expanded lip in the 

 young shell, from which circum- 

 stance it is frequently taken for the 

 buccinum and murex. 



The Linnean arrangement of shells, 

 consists of three orders, viz. Multi^ 

 valve, JBivalve, and Univalve. 



The first order, multivalve, are 

 shells consisting of more parts than 

 two. Every part of a shell which is 

 connected by a cartilage, ligament, 

 hinge, or teeth, is called a valve of 

 such shell. 



The second order, bivalve^aire shells 



