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1409 



TERTIARY FAUNA OF FLORIDA 



Subgenus Cardiocardita Anton, 1839. Type Cardita ajar Bruguiere. 



Hinge normal, pallial line with a broad scar in the locality usually marked 

 by a sinus in groups with a sinuate pallial line, shell veneriform. 



Agaria Gray, 1847; Actinobolns Morch, 1853 ; and Azaria Tryon, 1872, are 

 synonymous. 



Subgenus Cossmannella Mayer Eymar, 1897. Type Cardita agyptiaca Fraas 

 (sp.). Egyptian Eocene. 

 Shell elongate-oval, the cardinal teeth feeble, the ribs slender and distant, 

 the pallial line simple. 



Subgenus Cardites Link, 1807. Type Cardita antiquata Linne (sp.) := C. 

 sulcata Bruguiere. 

 Shell like Venericardia s. s., but the anterior right cardinal absent ; the 

 laterals obsolete. Recent. 



Section Cardites Link s. s. (See above.) 

 Shell more or less colored ; frequenting warm seas. 



Section Cyclocardia Conrad, 1867. Type Cardita horealis Conrad. 

 Pleistocene and recent. 

 Shell white, with a rude periostracum, the female incubating the nepionic 

 young in the atrium of the ovary. Boreal and colder waters of the globe. 



Subgenus Pleuromeris Conrad, 1867. Type Cardita tridentata Say. Miocene 

 and recent. 

 Shell small, subtriangular, nearly equilateral, the hinge like Venericardia 

 but the anterior and posterior right cardinals feeble, the left valve with feeble 

 anterior and posterior laterals. 



Subgenus Pteromeris Conrad, 1862. Type Astarte perplana Conrad. Oligo- 

 cene and recent. 

 Shell small, high, the anterior end longer, with narrow umbones and radial 

 ribbing, a well-marked lunula and escutcheon present, the hinge as in Cardites. 



Subgenus Miodontiscus Dall, 1903 (new name) ^= Miodon Carpenter, 1864 ; 



not Sandberger, 1870, nor Dumeril, 1859. Type M. prolongatus Cpr. 



Pliocene to recent. 



Shell not unlike Pteromeris, which has the anterior right cardinal missing 



and no laterals, while Miodontiscus has the posterior right cardinal absent and 



a posterior right and anterior left lateral feebly developed. 



