82 Geological Survey of Alabama. 



with one cardinal and two obsolete distant lateral teeth ; inner surface 

 with radiating impressed lines, which crenulate the margin ; outer surface 

 with concentric elevated distinct lines ; except on the umbo they are sep- 

 arated by rather large and regular distances. 



Locality. Claiborne, Ala. 



The radiating lines of the inside correspond, at some places near the 

 margin, with indistinct rib-like elevations of the surface. By a mistake, 

 the figure of this species, on plate 1, shows two teeth below the beak in- 

 stead of one. 



MACTRA IN.EQUILATERALIS, n. sp. PI. 1, fig. 18. 



Substance of the shell thick ; inequilateral ; triangular ; anteriorly 

 rounded ; posterior slope carinated ; covered with indistinct concentric 

 lines, which are distinct on the extremities. 



Locality. Vicksburg, Miss. 



As Conrad describes and figures Mactra funerata* as equilateral, I am 

 unable to refer the figured specimen to his species. 



HlNDSIELLA FAB A, n. Sp. PL 1, fig. 25. 



Small, convex ; sinus of the ventral margin gently rounded ; covered 

 with irregular lines of growth ; muscular impressions ovately elongated ; 

 an indistinct oblique tooth below the beak (right valve). 



Locality. Claiborne, Ala. 



Allied to Hindsiella arcuata, Lam., sp.f of the Paris basin. 



ERYCINA WHITFIELDI, n. sp. PI. 1, fig. 29. 



Small; substance of the shell thin, porcellaneously shining; oval; con- 

 vex ; insequilateral, the anterior side the largest ; left valve with two 

 obsolete pyramidal teeth on the anterior side, and on the posterior side 

 a compressed one, which is very small and distant from the beak ; surface 

 shining, smooth, except very fine concentric lines of growth ; margin 

 entire. 



locality. Claiborne, Ala. 



The nearest species in the Paris basin seems to be Erycina obsoleta, 

 Desh.'| Named after Prof. R. P. Whitfield, whose descriptions and figures 

 of American Eocene shells belong to the most careful ones. 



* Jour. Ac. Nat. Sci., I., 2d Series, 1848, p. 121, pi. 12, fig. 13. 

 f Desh., An. s. verteb., I., p. 695, pi. 53, figs. 32-35. 

 t Desh., An. s. vexteb., I., p. 720, pi. 53, figs. 16-19. 



