TRANSACTIONS OF WAGNER 

 1470 



^' TERTIARY FAUNA OF FLORIDA 



Crassatellites clarkensis Dall. 

 PLATE 36, FIGURES 20, 21, 24, 25. 



Crassatellites clarkensis Dall, Trans. Wagner Inst., iii., pt. v., p. 1192, pi. xxxvi., figs. 20, 

 21, 24, 25, 1900. 



Eocene of the Wahtubbee Hills, Clarke County, Mississippi, Burns ; near 

 Saline Bayou, St. Maurice, Louisiana, Vaughan ; and at Claiborne, Alabama, 

 L. C. Johnson. 



Shell solid, elongated, moderately thick, inequilateral, the anterior end 

 shorter, nearly equivalve; anterior end rounded, posterior end obliquely de- 

 scending, pointed, and subrostrate, with a marked carina from the umbo to the 

 posterior angle ; lunule and escutcheon subequal, lanceolate, impressed ; sur- 

 face smooth except for incremental rugae and microscopic radial striation ; 

 nepionic shell small with about six sharp, low, concentric ridges, which cease 

 abruptly in less than three millimetres from the apex ; hinge well developed ; 

 scars of ligament and resilium of moderate size ; third right (posterior) car- 

 dinal nearly intact and distinct; anterior and basal margins sharply, finely 

 crenate, the subsurface layer of the shell weathering out with distinct ribs 

 corresponding to the crenations. Lon. 42.5, alt. 26.5, diam. 19.0 mm. 



This resembles C. protextus, from which it is easily separable by its more 

 pointed rostrum, sinuate below, and the very small space occupied by the nepio- 

 nic sculpture, which in C. protextus extends over a radius on the disk of some 

 eight or ten millimetres. The latter also has more conspicuous radial striation 

 and coarser crenations. 



Crassatellites (Scambula) psychopterus Dall. 



PLATE 42, FIGURES 8, 9. 



Crassatellites psychopterus Dall, Trans. Wagner Inst., iii., part v., p. 1198, pi. xlii., figures 

 8, 9, 1900. 



Eocene of the Wahtubbee Hills, Clarke County, Mississippi ; Burns.. 



Shell thin, flat, ovate, rounded in front and behind, the anterior end 

 shorter; surface smooth except for incremental lines and three or four low, 

 distant, concentric ridges ; nepionic shell with little or no sculpture ; lunule 

 and escutcheon linear or obsolete; left valve with two well-marked cardinals, 

 the posterior dorsal margin with a shallow groove for the edge of the oppo- 

 site, valve; basal margin with a row (in the adult) of minute pustuliform 

 crenations. Lon. 20.0, alt. 15.0, semi-diameter 1.3 mm. 



The single valves upon which (with a fragment of a larger specimen) this 

 species is founded are undoubtedly young; the crenations do not appear on 



