TRANSACTIONS OF WAGNER 

 1402 



TERTIARY FAUNA OF FLORIDA 



spoon-shaped ; general form irregular ; the specimen figured is more trans- 

 verse than usual ; hinge normal, the teeth not very prominent ; ligament and 

 resilium coherent, equally long, extending into a deep groove below the broad 

 surface of attachment; visceral area of the valves smooth with a marginal 

 smooth border ; the outer edge is minutely granular, outside of which is a more 

 or less irregularly radiately striate or granular margin to the edge of the 

 valves ; adductor scars well marked. Lon. of figured specimen 83, alt. 68, diam. 

 about 45 mm. 



This fine species recalls C. macerophylla, but differs in the posterior furrow, 

 the radially grooved and appressed lamellae, and apparently in being larger 

 when adult. It was found at Shell Creek, where it was not very rare, and 

 sparsely on the Caloosahatchie near the site of old Fort Denmead, at a point 

 called Fourmile Hammock. 



Chama crassa Heilprin. 

 Chama crassa Heilprin, Trans. Wagner Inst., i., p. 93, pi. xii., fig. 27, 1887. 



Pliocene marl of the Caloosahatchie ; Heilprin and Dall. 



This species is easily recognized by its ponderous valves exhibiting two or 

 more whorls, with close, low lamellation, devoid of spines or foliations, and 

 of a turbinate shape with a deep, wide, radial posterior sulcation. In perfect 

 specimens the appressed margins of the lamellae are radially striate. It has the 

 character, very rare in Chama, of entire, non-crenulate inner margins to the 

 valves. The most nearly related recent species is perhaps C. lobata of the 

 Pacific. 



Chama caloosana n. sp. 

 PLATE 54, FIGURES 2, 5. 



Pliocene marls of the Caloosahatchie, Shell Creek, and Alligator Creek, 

 south Florida, Dall and Burns ; Pliocene of Trinidad Island at Matura, Guppy. 



Shell of moderate size, attached by the whole of the anterior end of the 

 right valve, with a sharp, narrow, radial sulcus near the posterior dorsal border, 

 on each side of which in the normal individual is a radial series of a few, flat, 

 triangular, radially striated foliations; in specimens having no foliations the 

 sulcus is inconspicuous ; the surface otherwise is concentrically striate with 

 traces of obsolete oblique or even divaricate radial threading ; the left valve is 

 flattish, subquadrate, with an analogous but narrower sulcus bordered with 

 flat, radially striate foliations ; there are sometimes a few anterior foliations 

 and the divaricate surface sculpture is more apparent than on the fixed valve; 



