THE NOMENCLATURE 



OF 



CONCHO LOGY. 



UNIVALVES. 



THE SEVERAL PARTS OF UNIVALVE SHELLS WITH 



THEIR SPECIFIC MARKS^ FORMS^ AND 



DISTINCTIONS. 



Anfractus. The Wreaths or Whorls^ the cir- 

 cumvolutions of the spire around the Co- 

 lumella, are either 



ancipites. Two-edged; longitudinally carinate at 

 the sides, or 



lifidi. Bifid; divided transversely by a line or 

 furrow, as it were, by a suture. 



canaliculati. Channelled ; having a small exca- 

 vated channel along the suture. 



