EXPLANATION OP TERMS. 211 



Bivalve. A shell with two valves ; from bis, 



twice, and valve. 

 Bifid. Cleft in two ; from bis, twice, and fid t, 



I have cleft. 

 Bifurcated. Having a fork of two teeth ; from 



bis, twice, and furc a, a fork. 

 BranchicK. Gills ; from the Greek foayxia 



(branchia) the gills offish. 

 Cardo or Hinge. In bivalves, that part of the 



circumference where the valves cohere. 

 Carinate. Furnished with a keel-like elevated 



ridge ; from carina, a keel. 

 Columella. The pillar round which the whorls 



form their spiral circuit ; from colum e//a, 



a little column. 

 Convoluted. Rolling regularly over each other ; 



from con, together ; and volut ws, rolled. 

 Cephalopodes. Having feet on the head ; from 



the Greek Ke<j>a\n (cephale) a head, and 



TroSes (podes) feet. 



Corneous. Horny ; from cornu, a horn. 

 Crenated. Notched ; from cren , the notch of 



an arrow. 

 Coriaceous. Like leather ; from cori ww, skin, 



leather. 

 Callosity. Hardness of skin or flesh ; from call 



us, which has the same signification. 

 Ciliated. Furnished with a fringe like eye-lashes; 



from cila, an eye-lash. 

 Cancellated. Crossed like the bars of a latticed 



window ; from cancelli, lattice. 

 Complicated. Folded together ; from con, with, 



together, and plica re, to fold. 



