TRANSACTIONS OF WAGNER 

 I 304 



•-^ ^ TERTIARY FAUNA OF FLORIDA 



When perfect the surface is finely, closely, sharply concentrically striated, 

 the even sculpture broken here and there by resting stages. A faint reflection 

 of radial striation sometimes appears towards the base on the most convex 

 part of the disk. The beaks are low, pointed, and prosogyrate, the lunule 

 cordate and striated, defined by an incised line. The escutcheon is bordered 

 on each side by a strong, rounded keel, is slightly excavated and flattened, 

 with the striation more feeble than on the disk ; in front of the keels is a wide, 

 shallow sulcus, corresponding to a concave flexuosity of the posterior base 

 which more or less strongly rostrates the shell. The internal basal and anterior 

 margins are finely crenulate ; the pallial sinus is small and angular ; the two 

 larger right cardinals are feebly grooved. The external striation sometimes 

 becomes a low lamellosity, the surface being harsh to the touch. 



Anomalocardid penita Conrad appears to dififer by a more slender and elon- 

 gated shell, the posterior end of which shows hardly any flexuosity, but is 

 extended like that of A. caloosana, while the lunular region is much less 

 impressed than in A. Uoridana. 



This form is not typical, but might be regarded as a precursor, in which 

 Anomalocardia is developing from Chione. 



Anomalocardia chipolana n. sp. 

 Plate 55, Figure i. 



Oligocene of the Chipola horizon at Alum Blufl:, Calhoun County, Florida ; 

 Burns. 



Shell small, trigonal, produced behind, sculptured with elevated concentric 

 lines, more crowded towards the base; both lunule and escutcheon feebly 

 defined, beaks low and pointed ; hinge very delicate, normal, the internal mar- 

 gins faintly crenulate ; both ends of the shell rounded, the base with hardly 

 any flexuosity. Length 6.5, height 5.0, diameter 3.0 mm. 



A single valve, perhaps young, was obtained and is named to fix the pres- 

 ence of the genus in these beds, from which it has been otherwise, so far, 

 unknown. 



Anomalocardia bowdeniana n. sp. 

 Plate 57, Figure 7. 

 Oligocene of the Bowden marl, Bowden, Jamaica. 



Shell small, ovate-trigonal, subrostrate, with a flexuous base behind ; beaks 

 rather high, prosogyrate; lunule large, impressed', well defined, but with no 

 defined escutcheon ; posterior end pointed, anterior end rounded, base arcuate, 



