Quercus. AMENTACEZ. 5 
They vary in size from two and one half to five centimeters long, and 
from one to two centimeters broad. The secondary veins are in a very 
open angle of divergence from the narrow midrib, often, especialiy in the 
small leaves, in right angle to it, curved toward the borders, camptodrome, 
with primary areas generally divided to the middle by thin tertiary veins. 
As in the former species, to which it is related by its areolation, the ner- 
villes in right angle to the secondary veins are divided by cross branches, 
generally oblique, passing by multiple ramifications into very small areol, 
not as distinctly quadrangular as in the former species, but rather irregu- 
larly polygonal. 
This species is also related to Quercus elena, Ung., but essentially differs 
by the form of its shorter leaves. It is more closely allied to the Live 
Oak, Q. virens ; to the var. nana by its nervation, and to the var. maridima 
by the form and size of the coriaceous leaves. I have mentioned as Quer- 
cus virens, from the Pliocene chalk bluffs of the Mississippi, Amer. Journ. 
of Sci. and Arts, 1859, Vol. XXVII. p. 364, leaves which appear identical 
with those described here. 
Habitat. — Same locality as the former. Voy’s Collection. 
§ II.— Leaves SERRATE OR DENTATE. 
Quercus Nevadensis, sp. nov. 
Pl. IT. Figs. 8, 4. 
Leaves obovate, rounded to an obtuse point, gradually narrowed from the middle to the 
base ; borders distantly dentate ; nervation subcamptodrome. 
We have of this species only the two specimens figured. The length 
of the leaves is nine to eleven centimeters, and their width from three 
to five; their shape is obovate or oblanceolate, as they gradually enlarge 
upwards from a narrowed base, and are rounded to an obtuse point. The 
teeth of the borders are distant and short, generally turned outside, sepa- 
rated by shallow sinuses, and descend to below the middle of the leaves, 
even, in the small specimen, to near the base. The secondary veins are 
close, sixteen pairs in each leaf, parallel, mostly simple, passing from the 
middle nerve, at an angle of divergence of 50°, nearly straight to the 
borders, where they abruptly curve, entering the teeth by a short branch, 
a nervation of the same type as that of the dentate leaves of Dryophyllum. 
The nervilles are very distinct, somewhat distant, mostly simple and de- 
