NOMENCLATURE. 41 



BIVALVES AND MULTIVALVES, 



Ambitus. Circumference of the shell. 



Area. Slope. 



antica. Anterior slope or Area ; that side of the 



beaks or that space in which the ligament 



is situated. 

 distincta. Distinct 3 separated from the sides of 



the shell either by a channel or a keel. 

 inflexa, Inflex^ having incurved lips. 

 literata. Literate; ornamented with characters 



like letters. 

 postica or Areola. Posterior slope; the other 



side of the beaks. 

 marginata. Marginate ; surrounded by an ele- 

 vated margin. 

 paiula. Patulous ; the margins of the areola 



gaping. 

 serrata. Serrate ; saw-like in the channel of the 



areola. 

 Apices. Beaks; the tips or extreme parts of 



the umbones or bosses. 



