224 DESCRIPTION OF SPECIES. 



QUERCUS, Linn. 



Quercus Dentoni, sp. nov. 

 Plate XLVIII, Figs. 1,11. 



Leaves of medium size, coriaceous, elliptical-obloug, very entire, obtuse, narrowed 

 or rounded to a short petiole ; borders slightly reflexed ; secondary nerves open, nearly 

 at right angles toward the base, generally more oblique upward, caniptodrome at a 

 distance from the borders, anastomosing in two series of marginal areoles and sepa- 

 rated by intermediate tertiary shorter nerves, branching and anastomosing at right 

 angles; ultimate areolation small, quadrate. 



The two fragments of leaves preserved indicate the characters of the 

 species. One of them is nearly 10 centimeters long and 3 centimeters 

 broad ; the other is broader but the upper part is destroyed. By the nerva- 

 tion the species is related to Q. chlorophylla, Ung., or at least it is of the 

 same type. The leaves of this last species are always much smaller and 

 the nervation less distinct. 



Hab. — Bad Lands, Dakota. Professor Wm. Benton. 



Quercus Olafseni, Heer. 



Plate XLVIII, Fig. 4. 



Heer, "Fl. Arct.," i, p. 109, pi. x, fig. 5; xi, figs. 7-11 ; xlvi, fig. 10. 



Leaves membranaceous, large, short-petiolate, narrowly elliptical, doubly serrate 

 on the borders ; teeth obtuse ; secondary nerves parallel, slightly curved, some of them 

 forking near the borders, camptodrome. 



Though I have only seen the fragment figured, it is sufficiently char- 

 acterized to show its identity with Heer's species, which is common in the 

 Greenland Miocene. The lateral veins are a little more curved in passing 

 to the borders than represented in most of the figures of Heer. 



Hab. — With the preceding. Professor Wm. Denton. 



Populus Richardsoui, Heer. 

 " U. S. Geol. Rep.," vii, p 177. 



The leaf which I refer to this species is smaller than any of those 

 figured. It is only 3 centimeters long and 2 broad. As the leaf is oval, 

 narrowed, cuneate to the base, it cannot be referred to P. arctica. It 

 resembles P. mutabilis oblonga, Heer, " Fl. Tert. Helv.," but I consider it 

 as a small form of P. Bichardsoni. 



Hab. — Bad Lands, Dakota. Professor McBride. 



