56 Bulletin 4 170 



terior-basal margin; within, of the same dark brown polished 

 appearance that characterizes the interior of Yoldia eborea; an- 

 terior row of teeth equaling or surpassing in strength and length 

 those of the posterior. 



This species is plainly the ancestor of L. robusta Aid. from 

 Wood's Bluff. It differs from his species in having much finer 

 striae which continue over the whole surface of the valve; in 

 rabusta the anterior-dorsal region is nude. L. quercolUs is about 

 two-thirds the dimensions of L. robvsta, has a much less angular 

 appearance and a fainter radiating posterior sinus. 



Localities. — Alabama: i mi. W. of Oak Hill P. O., Wilcox 

 Co.; Dale's Branch near Oak Hill P. O., Wilcox 

 Co. 



Type. — Paleontological Museum, Cornell Univ. 



YOLDIA. 

 Yoldia kindlei n. sp., PI- 4, fig"- 6. 



Specific characterization. — Size and general form as indicated 

 by the figure; surface in casts smooth, but in some well preserved 

 fragments indicating more or less regular lines of growth; some- 

 what inflated. 



Named in honor of a most energetic and promising young 

 paleontologist of this University. 



Locality. — TknnesskE: i^ mi. N. of Crainesville, at Hannah's, 

 Hardeman Co. Bed f. 



Type. — Paleontological Museum, Cornell Univ. 



Yoldia eborea, PI. 4, fig. 7. 



Syn. Leda eborea Con., Jr. Ac. Nat. Sci. Phila., vol. iv, i860, 

 p. 295, pi. 47, fig. 26. 



Conrad's origiiial description. — "Triangular, equilateral, ven- 

 tricose, smooth, polished; lunules of equal length and defined by 

 carinated lines; anterior lunule widely elliptical; dorsal margin 

 when the valves are together defined by a slight carina; a slight 

 furrow near the posterior dorsal margin and parallel with it; pos- 

 terior end acutely rounded and submargin slightly contracted; 

 base regularly rounded. 



" Length, ^ inch." 



There is considerable variation in the size as well as the shape 

 of this species. The Tombigbee river specimens are larger and 

 longer than those from the Alabama river exposures; yet they 



