li2 C N C H L O G Y. 



whatever, are capable of liot Dniy addliig 

 to the extent and growth of their Shells^ 

 but can likewifej from time to time, add 

 a frefli poUfhed covering to the whole 

 Shell ; at leaft their organs extend to fuch 

 a length as to clear away all impurities 

 from their Shells. We feldom find any 

 Cowries with Coral or any extraneous 

 bodies adhering to any part of them. 



The head (apex) of an Univalve is the 

 part jufl over the mouth or aperture. The 

 bafe end or tip, (bafin feu acumen) that part 

 oppolite to it, or the end ofthe turban, though 

 fome authors have given them quite contra- 

 ry names, by calling the tip or end the part 

 over the mouth. In fpeaking of Shells 

 it may be underftood, that when the up- 

 per or under fide, or ends are mentioned, 

 it is fuppofed that the Shell lies on its 

 mouth upon a table, with the head towards 

 •the right hand, and the end or tip towards 

 the left. 



The 



