18 FOSSIL FLORA OF THE SIERRA NEVADA. 
Ficus tilizfolia, Al. Br. 
Pi. LV. Figs. 8,9. 
Leaves large, subcoriaceous, entire, unequilateral, palmately three or five nerved, ovate, 
rounded or subcordate at the base, pointed or acuminate ; petiole thick. 
This species differs from the former by its thinner primary nerves, and 
their divisions ascending nearly straight to the borders, where they ab- 
ruptly curve in bows, often touching the margins; by the distinctly unequi- 
lateral base of the more narrowly pointed leaves, and the square primary 
areolation. This species is well known, its characters definite, and its dis- 
tribution very wide. The leaves greatly vary in size, Fig. 9 representing 
its small forms, Fig. 8 the middle ones, for there are leaves of this spe- 
cies twice as large. It has been described by European authors from 
most of the stages of the Miocene. On this continent we find it already 
in the lowest strata of the Eocene Lignitic, as at Point of Rocks, for 
example, quite near the top of the Cretaceous measures. It abounds at 
Golden, Colorado, Black Buttes, Wyoming, etc., and is therefore repre- 
sented in the whole Tertiary. No species has been seen in the Creta- 
ceous Dakota group, however, which could indicate any relation to it. 
The type is represented at the present time by Fieus sycomorus, Linn., an 
analogous species. 
Habitat. — Chalk Bluffs, California. Voy’s Collection. 
Ficus microphylla, sp. nov. 
Pl. LV. Fags sas: 
Leaves small, coriaceous, very entire, broadly oval or rhomboidal in pein rounded 
upwards to a short obtuse point, and downwards to a thick petiole ; palmately three- 
nerved from the slightly unequilateral base ; nervation camptodrome. 
The species is represented in the collection by three leaves, all about 
of the same size, the largest three centimeters long, and a little more — 
than two centimeters broad. The nervation is of the same character as 
that of the two former species; but the primary nerves are very thin, 
in three only, and on «a more acute angle of divergence than that of 
the secondary ones. The lateral nerves ascend to above the middle 
of the leaves, where they curve near the borders, anastomosing by simple 
flexure with the secondary veins, which are scarcely branched, merely 
