156 DESCRIPTION OF SPECIES. 



not entire bnt distantly dentate, and the base slightly decurrent to a thick 

 short petiole. In the European species the leaves are mostly entire, but 

 sometimes also denticulate in the upper part, and the base of the leaf is 

 not as decurrent, while the petiole, generally thick, is a little longer. The 

 nervation is as represented in Heer, "Fl. Tert. Helv.," ii, pi. Ixxiv, fig. 4. 

 ^«5.— Randolph Co., Wyoming. U. S. Geol. Expl. Dr. F. V. Hayden. 



CASTANEA, Linn. 

 Casta Ilea iutermedia, Lesqx. 



" U. S. Geol. Rep.," vii. p. IM. pi. xxi, fig. 7. 



SALICINE^. 



SALIX, Linn. 

 Salix amygdala? folia, sp. nov. 



Plate XXXI, Figa. 1,2. 

 "U. S. Geol. Rep.," p. 165. 



Leaves narrowly lanceolate, tapering to a blunt acumen, rounded in narrowing 

 to tbe petiole, serrulate; lateral nerves at an acute angle of divergence. 



The leaves, 6 to 7 centimeters long, 12 to 15 millimeters broad, with 

 a slender petiole 2 centimeters long, may seem to represent a variety of 

 6'. varians, Goepp., so common in the European Miocene. But they are 

 generally much smaller, more narrowly lanceolate ; the secondary nerves, 

 especially the basilar ones, at a more acute angle of divergence; the bor- 

 ders more distinctly serrate-crenate. The form of the leaves is the same 

 as in S. lavateri, Al. Br., but the leaves of this last species are much longer. 



Hah. — Florissant. Seen in the different collections from that locality. 

 • 



.Salix Libbeyi, sp. nov. 

 Plate XXXI, Fig. 3. 



Leaves large, thick, •oblong, enlarged upward, rapidly narrowed to the point, 

 tapering to the base, very entire. 



The nearest relation of this species is S. ahhremata, Goepp., "Schoss. 

 Fl.,"" p. 25, pi. xvii, iigs. 4-11, especially like fig. 7; but the American leaf 

 is twice as large, 8 centimeters long, 2J broad in the upper part, narrowed 

 to the base, which is not rounded, and more enlarged upward. 



Hah. — Florissant. Princeton Museum, No. 780. 



