1895.] NATUKAL, SCIENCES OF PHILADELPHIA. 49 



Genus CRASSATELLA. 

 Crassatella texalta nov. sp. PL 2, fig. 2. 



* Specific characterization. General form as figured; exterior smooth 

 about the umbones, but marked by lines of growth anteriorly and 

 sub-basally; hinge and marginal crenulations as in C. alta Con. 



This species is closely allied to C. alta, but is distinguished by its 

 proportionally longer form and its smooth umbones, the latter feature \^ 



being in marked contrast with the corrugations of C. alta. It 

 evidently does not attain the large dimensions of Conrad's species. 



Localities. Alabama Bluff, Trinity River, Houston Co. ; Hurri- 

 cane Bayou, Houston Co. , Tex. ; 2 \ miles east of Newton, and 4 

 miles west of Enterprise, Miss. 



Geological horizon. Lower Claiborne Eocene. 



Type specimen. Texas State Museum. 

 Crassatella trapaquara nov. sp. PL 2, fig. 3. a 



Specific characterization. General form as figured ; surrace con- 

 centrically striate anteriorly , smooth posteriorly, except a few shal- 

 low concentric depressions marking periods of growth ; hinge teeth 

 'not so strong as in texalta; lunular margin concave; basal margin . 



of the valves but slightly convex, crenulated within anteriorly and \^ 



basally but not posteriorly. 



Localities. Smithville, Bastrop Co.; 8 miles east of Alto, Chero- 

 kee Co.; Elm Creek, between OrrelPs and Evergreen Crossing, 

 Lee Co.; Murchiaon'e Headlight, northern boundary, Houston Co.; 

 R. Williams' Headright, northeast of Weches, Houston Co., Tex. 

 Also Moore's Iron Mine, La. , and near Enterprise, Miss. 



Geological horizon. Lower Claiborne Eocene. 



Type. Harris' collection. 



Crassatella antestriata Gabb. PL 1, fig. 10, a. 



C. antestriata Gabb, Journ. Ac. Nat. Sci. Phila., vol. iv, 1860, p. 388, pi. 67, 

 f. 53. 



Gabb's figure and description were of a young specimen ; the 

 figure herewith given is of an adult. Compared with trapaquara, 

 antestriata is much more oblique, or inequilateral, the posterior ex- 

 tremity is sub-biangular and crenate within, and the basal margin is 

 more convex. Externally antestriata is more strongly marked. 



Localities. Lee Co. ; Elm Creek, between Evergreen and OrrelPs 

 Crossing, Lee Co.; Alabama Bluff, Trinity River, Houston Co.; 



