96 Bui^i^ETiN 31 96 



teeth — two cardinals in the left valve, one in the right, an anter- 

 ior lateral shallow socket in the right, a posterior in the left. 



It appears that the large cardinal tooth in the right valve 

 does not fill all the space between the two of the left, especially 

 just beneath the apex, and we are inclined to believe a trace of a 

 resilium ma}^ be present. 



Type, specime7is fig7(red, etc. — Paleont. Museum, Cornell 

 Univ. ; from the Claiborne sand beds, Claiborne, Ala. 



Crassateliites trapaquarus Harris, PI. 33. Figs. 1-5. 



Crassatella trapaquara Har. , Proc. Phila. Acad. Nat. Sci., 1895, p. 



49, Pl- 2, fig. 3, a. 

 Harris' original description. — General form as figured, surface con- 

 centrically striate anteriorly, smooth posteriorly except a few, shallow con- 

 centric depressions marking periods of growth ; hinge teeth not so strong as 

 in texalta ; lunular margin concave ; basal margin of the valves but slight- 

 ly convex, crenulated within anteriorly and basally but not posteriorly. 



This seems to be the direct descendant of halei — of the Sa- 

 bine but shows a much broader posterior rectilinear margin, 

 sharply defined concentric markings on the anterior and crenula- 

 tions about the margin as described above. The species halei is 

 somewhat intermediate between tiimidula and trapaquara. The 

 beaks for about ten millimeters are sharply and beautifully 

 grooved concentrically, but even here this marking fails com- 

 pletely behind the umbonal ridge. The erect, nearly central um- 

 bones of this species distinguish it at once from the oblique semi- 

 ovate antestriata. 



Type. — Paleont. Mus. Cornell Univ., from vSmithville, Tex. 



Horizon. — St. Maurice. 



Speci77iens figured. — Paleont. Mus. Cornell Univ., Tex. and 

 lyisbon. 



Localities. — Smithville, 8 miles E. of Alto, Elm Cr., north- 

 ern boundary Murchison's headright, N. E. of Weache's, Hous- 

 ton Co., Texas; Moore's Iron Mine, "Marble Quarry" and Fill- 

 more 2 miles W. of Houghton, La. ; Chickasawhay River and 

 Graveyard Bridge near Enterprise, and Johnson's Place, Miss. ; 

 Lisbon and Coffeeville (compres.sed form), Ala. One specimen 



