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TERTIARY FAUNA OF FLORIDA 



rather prominent mesially ; surface sculptured with concentric strise with 

 flattish wider interspaces ; hinge normal, rather heavy, inner margins entire ; 

 pallial sinus small, angular. Length 4.5, height 3.5, diameter 3.0 mm. 



The small valve from which the above description is drawn up (the diameter 

 as usual being twice the diameter of the valve) is up to the present time the 

 sole representative of the genus known from the Bowden marl. It is doubtless 

 immature. 



Anomalocardia dupliniana n. sp. 

 PLATE 55, FIGURE n. 



Upper Miocene of the Natural Well, Duplin County, North Carolina; 

 Burns. 



Shell small, trigonal, high, with high, quite anterior beaks, the lunule and 

 escutcheon not defined ; anterior end rounded ; posterior end produced, blunt ; 

 base moderately arcuate, not flexuous ; surface smooth with feeble concentric 

 striation, stronger posteriorly ; hinge normal, feeble ; inner margins entire ; 

 pallial sinus small, angular. Length 5.0, height 4.2, diameter 2.5 mm. 



In this case also a single juvenile valve represents the genus in this horizon. 

 In the older Miocene of Virginia and Maryland conditions were so much 

 colder that it seems improbable that Anomalocardia, which is a tropical or sub- 

 tropical genus, will ever be found. 



Anomalocardia caloosana Dall. 



PLATE 42, FIGURE 10. 



Venus {Anomalocardia) caloosana Dall, Trans. Wagner Inst., iii., p. 1198, pi. xlii., fig. 

 10, 1900. 



Pliocene of the Caloosahatchie beds, on the Caloosahatchie and Myakka 

 Rivers and Shell Creek, Florida ; Pleistocene of North Creek, near Osprey, 

 Florida. 



Shell elongate, with low, pointed beaks, the anterior end rounded and 

 swollen, the posterior end compressed, attenuated, and rostrate ; the posterior 

 dorsal slope long and straight; the base convex and slightly flexuous behind; 

 sculpture of concentric waves, not coincident with the lines of growth and 

 steeper on their dorsal slopes ; these frequently become enfeebled or obsolete 

 between the middle of the shell and the radial ridge bounding the escutcheon; 

 lunule defined by an impressed line, lanceolate and narrow ; escutcheon striated, 

 impressed, bounded by a radial ridge which extends from the beaks to the 

 rostrum ; hinge delicate, normal, the rugosities distinct when adult ; basal 



