FLOEA OF THE DAKOTA GKOUP. 39 



QUERCUS, Linn. 



Quercus Dakotensis, sp. nov. 



Leaf subcoriaceous, ovate-lanceolate, narrowed in rounding to the base, less 

 abruptly, however, to an acute or blunt apex (not distinct), entire on the borders toward 

 the base, nearly regularly dentate from below the middle upward, short pedicellate; 

 medial nerve straight; secondary nerves thin, slightly bowed, divided into two or three 

 branches, each entering a tooth. 



The leaf is 9 centimeters long and 4i centimeters broad in the middle; 

 the point not distinct appears blunt; the pedicel is slender, nearly 1 centi- 

 meter long as far as it is seen before entering the stone; the secondary 

 nerves diverge 55° to 60°. 



The species is related to Quercus Beyrichii, Ett., "Kreidefl. von Nied- 

 ers.," p. 14, pi. ii, fig. 2, from which it differs by the teeth not being turned 

 upward or serrate, but abruptly acuminate outward; by the texture, which 

 is not distinctly coriaceous; by thin secondary nerves and a narrow straight 

 midrib. The upper veins are under the same angle of divergence, craspe- 

 dodrome; the lowest pair, attached a little above the base of the leaf, 

 follows the entire border up to the lower teeth. This species has also a 

 degree of affinity to Castanea Hausmanni, Dkr., ''Paleont.," iv, p. 181, pi. 

 xxxiv, fig. 1. The teeth are of the same character. 



These three species may be referable to the preceding genus, but the 

 tertiary divisions of the veins are not discernible in any of them. 



Hab. — South of Fort Harker. Ohs. Sternberg. No. 62, Mus. Comp 

 Zool., Cambridge. 



Quercus hexagona, Lesqx. 



"U. S. Geol. Rep.," vi, p. 64, pi. v, fig. 8. 



This leaf, to which I could not indicate any related form when I 

 described it (1. c.), is, in shape especially, allied to the Oligocene Quercus 

 Osbornii, pi. xxxviii, fig. 17, which, itself, is comparable to Quercus tephrodes, 

 Ung., as figured in Sieber, "Nord-Bohm Braunkohl. Fl.,*' iii, fig. 17. 



Quercus Ellsworthiana, Lesqx. 



"U. S. Geol. Rep.," vi, p. 65, pi. vi, fig. 7. 



Another specimen referable to this 9pecies, as yet insufficiently repre- 

 sented and described, is a leaf of the same size and form as that of the 

 "U. S. Geol. Rep.," I. c. The nervation is of the same character, at least 



