38 

 CARDITA. 



GENERIC CHARACTER. 



* 



Shell subovate or suborbicular, with strong radi- 

 ating ribs; teeth in one valve two, generally oblique, 

 one of them elongated, thick, mostly rather curved, 

 the other sometimes straight, short, and thick ; in the 

 other valve, one elongated, thick, and oblique tooth, 

 and a deep elongated cavity for receiving the larger Ji 



tooth of the other valve ; margin crenulated ; palleal 

 impression entire. 



OBSERVATIONS. 



A genus formed by Bruguiere to receive part of 

 the Linnean Veneres, from which Lamarck has sepa- 

 rated the species of a suborbicular form, under the 

 name of Ve^icricardia ; in these the oblique position 

 of the anterior tooth alone distinguishes the hinge 

 from that of the Cm^ditse of Lamarck ; I have there- 

 fore adopted the present genus as defined by Blain- 

 ville and Sowerby, who include the Venericardise '^ 

 and thus it remains as originally constructed by Bru- 

 guiere. 



Both the recent and fossil species are numerous ; 

 and several of the latter occur in the tertiary of the 

 southern states. 



1*1 





