knowlton.] DESCRIPTION OF SPECIES. 45 
nervation are nearly identical, but the large pair of secondaries is much 
more liexuose, and the finer nervation is that of Ficus rather than that 
of Populus. 
Habitat. — Point of Rocks, Wyoming. 
Ficus hesperia n. sp. 
PI. IX, fig. 5. 
Fivussj). Kn., Stanton and Knowlton, Bull. Geol. Soc. Am., Vol. VIII, p. 140 (1897). 
Leaf rather broadly elliptical, about equally rounded from the broad- 
est point at the middle of the leaf to both base and apex; base wedge- 
shaped, apex very obtuse; margin perfectly entire; midrib very thick, 
slightly undulate; secondaries, about ten pairs, alternate, emerging at 
a very low angle, camptodrome, arching far inside the margin and join- 
ing by a broad regular bow to the one next above; apparently with a 
series of bows outside the secondary arches; ultimate nervation not 
preserved. 
The Dutton Creek material contains of this form the single example 
figured. It is cm. in length and 3 cm. in width. It is broadly ellip- 
tical in outline, broadly wedge-shaped at base, and obtuse and rounded 
at apex. The midrib is very thick, with about ten pairs of regular 
parallel secondaries, which join well inside the margin. 
Habitat. — Goal mine on north fork of Dutton Creek, near old stage 
road, Laramie Plains, Wyoming. Collected by Knowlton, Stanton, and 
Knight, July 28, 1896. 
Ficus squarrosa n. sp 
PI. VIII, fig. 2. 
Leaf of medium size, thick, irregularly quadrangular in outline, 
broadly rounded at base, truncate at apex with short obtuse point, 
leaf three-lobed, with very small, obtuse lateral lobes; palmately three- 
nerved; secondaries, about seven pairs, alternate, at an angle of about 
45°, all camptodrome, the lowest pair passing into the lateral lobes, 
provided with six or eight camptodrome branches on the outside; 
second pair of secondaries forked just above the middle; all second- 
aries above the lowest pair much arched toward the apex; nervilles 
strong, percurrent or forked, approximately at right angles to the 
secondaries. 
This species is characterized by its nearly square outline, small 
obtuse lateral lobes, rounded base, and short, obtuse apex. It is 8.o 
cm. long and about 7.5 cm. broad. The upper secondaries arch very 
strongly in the upper portion of the leaf, each joining by a series of 
short bows the secondary next above. 
This leaf is the only one observed in the collection. It is not quite 
perfect, lacking the central portion of the base and a portion of one 
