OP CONCHOLOGY. 26t 



TUREITELLA AlABAMIENSIS. 



Description. — Shell slender ; volutions twelve or more ; sub- 

 quadrangular, lower margin sometimes projecting; suture 

 distinctly marked; aperture sub-elliptical, sliglitly oblique; 

 surface marked by numerous fine revolving lines, which are 

 scarcely alternate, and crossed by distinct lines of growth, 

 which make a deep sinus on the body of the volution, and 

 are again bent backwards on the lower angle. 



This species scarcely differs from T. ceelata, Conrad, from 

 the Vicksburg (Miss.) beds, except that it is destitute of the 

 lines of granulas which give so decided a character to that 

 species. 



Locality. — Nine miles below Prairie Bluff, Alabama, r^a Tthet^ 

 CUCULLiEA, Lamarck. 

 CUCULLiEA MACRODONTA. — t. 27, f. 17. 



Description. — Shell of medium size, sub-rhomboidal in 

 outline, broad heart-shaped in profile; hinge line nearly as 

 long as the greatest length of the shell; hinge area broad, 

 corrugated; valves deep; beaks distant, slightly incurved; 

 surface marked by from forty-five to fifty low, radiating ribs, 

 which are finely corrugated by concentric lines; ribs indis- 

 tinct on the posterior part; a rather deep, narrow sulcus ex- 

 tends from the beak to the posterior basal angle, leaving a 

 prominent umbonal ridge; hinge line with sixteen teeth, the 

 right valve having four at each extremity, parallel to it; mus- 

 cular scars sub-quadrangular, the posterior much the largest; 

 muscular ridges faint or obsolete ; pallial line crenulate ; inner 

 margin of shell smooth. 



This species is remarkable for the very transverse lateral 

 teeth, a feature not often noticed in fossil species of the genus. 



Locality. — Nine miles below Prairie Bluff, Alabama. 

 CRASSATELLA, Lamarck. 



Crassatella tumidula. — t. 27, f. 16. 



Descrijjtion. — Shell sub-triangular or sub-clavate in outline ; 

 anterior end broadly rounded; posterior end narrow, acute; 

 valves ventricose in front, attenuate behind, with a shallow 

 sulcus in front of the umbonal slope; surface smooth, except 

 rugose markings on the umbones; hinge teeth moderately 

 large ; lateral tooth elongate, linear ; ligamental area shallow, 

 broad-triangular; muscular scars large; anterior subreniform; 

 posterior circular; margin of shell finely crenulate on the 

 anterior and antero-basal portions. 



Closely resembles C. pteropsis, Gabb, a Cretaceous species. 



Locality. — Six miles above Claiborne, Alabama, west side 

 of the river. 



