ELEMENTS 



OF 



CONCHOLOGY. 



INTRODUCTION. 



CoNCHOLOGY or Testaceology isthe sciencewhich 

 treats of the structure^ appearance, properties and 

 methodical arrangement of Shells, th». external 

 testaceous covering of certain moUuscoi animals. 



Testacea constitute the Hid Order c. Vermes^ 

 the Vlth Class of the Linnsean System oi Nature. 



This Order includes all shells of a calcareous na- 

 ture, that is, composed of carbonate of lime mix- 

 ed with some gelatinous matter, and exclude.? 

 those which are called crustaceous^ in the cover- 

 ing of which phosphate of lime is a constituent 

 part. 



