TRANSACTIONS OF WAGNER 

 1408 



TERTIARY FAUNA OF FLORIDA 



Subfamily CARDITIN^ 



Marsupium seated in the soft parts, not reflected in the structure of the 

 shell. 



Mytiloid forms. 



Genus Cardita (Bruguiere, 1792) Lamarck, 1799. Type Chama calyculata 

 Linne. 



Valves elongate-quadrate, strongly radially ribbed, very inequilateral, with 

 a slight ventral byssal gape. 



Section Cardita s. s. Type C. calyculata Linne. 



Hinge with two left and three right cardinals, the laterals obsolete in the 

 adult ; the inner margins of the valves usually fluted or serrate. 



Section Carditamera Conrad, 1838. Type C. arata Conrad. 



Valves with the laterals well developed in the adult, the right anterior 

 cardinal often obsolete. 



Section Glans Megerle, 1811. Type C. trapezia Linne. 

 Valves short, quadrate, convex ; the posterior right cardinal often obso- 

 lete ; the species usually small. 



Subgenus Beguina Bolten, 1798. Type Chama phrenetica Born. 



Shell large, mytiliform, subcompressed, with feeble radial sculpture, the 

 umbones terminal, the hinge as it were drawn out and arcuate, the lunule 

 tubular, the posterior cardinals much elongated, laterals absent. 



Azarella Gray, 1854, is synonymous. This peculiar shell seems to stand 

 alone, with no recent or fossil congener. It belongs to the Indo-Pacific fauna. 



Cardioid forms. 



Genus Venericardia Lamarck, 1801. Type V. imbricata Lamarck. Parisian 

 Eocene. 



v Shell rounded-trigonal, strongly radially ribbed, the ribs frequently beaded, 

 especially when young, the lunule minute and deep, the escutcheon linear, the 

 internal margins crenate, the hinge with two transversely striated cardinals in 

 the left and three in the right valve, the laterals absent or obsolete, a sublunular 

 pustule sometimes present in the left valve. Eocene to recent. 



Megacardita Sacco is probably synonymous, the form being slightly more 

 quadrate and elongate. 



