DESCRIPTIONS OF SPECIES. 71 



nition, and that since it is plainly different from any of its associates it will 

 be in the future identified and its structure and relations be more fully 

 made out. 



Formation and locality: Tertiary (Green River group). Green River, 

 Wyoming. 



Quercus castanopsis Newb. 



PL LVI, Fig. 4. 

 Proc. U. S. Nat. Mus., Vol. V (March 21, 1883), p. 505. 



"Leaves oblong-elliptical, rounded at the base; nervation regular; 

 midrib straight, branches parallel, simple, terminating in the principal teeth 

 of the margin; margins doubly dentate, the larger teeth receiving the 

 extremities of the nerve branches, and each carrying a minor denticle; 

 upper surface smooth; texture of the leaf coriaceous." 



Collected by Mr. S. M. Rothhammer. 



But a single specimen of this leaf is before us, yet this is so peculiar 

 and strongly marked that it seems to deserve description. In general aspect 

 it closely approaches the leaves of Castanea and Fagus, but the margins 

 are doubly dentate, a feature I have not found in any of the beeches or 

 chestnuts. It is present, however, in some of the chestnut oaks, as in Q. 

 Olafseni Heer (Fl. Foss Arct, Vol. I, p. 109, PI. X, fig. 5; XI, figs. 7-11; 

 XL VI, fig. 10). It seems safer, therefore, to refer the leaf to Quercus 

 rather than to the other genera mentioned. 



Formation and locality: Tertiary (Eocene?). Yellowstone River, 

 Montana. 



. Quercus consimilis Newb. 



PI. XLIII, figs. 2-5, 7-10. 

 Proc. TJ. S. Nat. Mus., Vol. V (March 21, 1883), p. 505. 



"Leaves petioled, lanceolate, acuminate, wedge-shaped or rounded at 

 base, where they are often unequal ; margins usually dentate, occasionally 

 only undulate, sometimes entire below, denticulate above; teeth acute, 

 often spinous, sometimes short and closely appressed; nervation fine and 

 regular; lateral nerves slender, parallel, generally arched upward; below, 

 where margin is entire, camptodrome; above, craspedodrome, the branches 

 terminating in the marginal teeth ; tertiary nervation consisting of minute 



