168 UNITED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



S a I i X media, Heer. 

 Plate XXII, Fig. 3. 



Salix media, Heer, Fl. Tert. Helv., ii, p. 32; iii, p. 17.'), pi. Ixviii, figs. 14-19. — Al. Br., Stizenb. Verz., p. 78. — 

 Ludw., PalajoDt., viii, p. 93, jil. xxviii, figs. 1-4. — Lesqx., Anuual Report, 1871, Supplement, 

 p. C; 1873, p. 411. 



Leaves entire, rounded at the base to a short petiole, linear, lanceolate-pointed, or gradually 

 taperirg to the point; secondary veins open, camptodrome. 



The figure represents one of two leaves upon the same* specimen, the 

 one not figured having the same character, rounded at the base, linear-lan- 

 ceolate to near the point where it is broken, and without any trace of secondary 

 veins. These are not generally visible upon the upper surface of the leaves. 

 Of those represented by Heer, one only (fig. 16) has its nervation discernible; 

 it is the same with those described by Ludwig. The identity is recognized, 

 however, by the form of the elongated, lanceolate, entire leaves, rounded to 

 the short petiole, a character distinctly marked in all the figures of this spe- 

 cies published by European authors, except in Ludwig's loc. cit., fig. 2, which 

 seems referable to another. The specimens from Elko agree also exactly 

 in the same characters, and their secondary nervation is still more obsolete 

 than in those of Green Kiver. 



Habitat. — Green River, Wyoming (Dr. F. V. Harjden); Elko Station, 

 Nevada {Prof. E. D. Cope). * 



Salix angusta, Al. Br 



Plate XXII, Figs. 4, 5. 



Salixangusta,Ai. Br., Stizenh. Verz., p. 77. — Heer, Fl. Tert. Helv., p. 30, pi. Ixix, figs. 1-11. — Lesqx., Annual 



Report, 1H71, Supplement, p. 6; 1872, p. 405. 

 Salix anguntifoUa, Al. Br., in Buckl. Geol., p. 512. 

 Salix avgustissima, Al. Br., in Leonh. und Bronn. Jahrb., 1850, p. 169. — Ung., Gen. et Sp., p. 418. 



Leaves entire, generally very long, and comparatively narrow, at least twelve times longer than 

 broad, linear-lanceolate, gradually tapering upward to a long acnmen and downward to a short petiole; 

 middle nerve thick; secondary veins close, numerous, more distinct than in the former species. 



This sjjecies essentially diifers from the former l)y narrower, much longer 

 leaves, either gradually narrowed to the point and fo the petiole, or linear, 

 with borders nearly parallel in the middle, tapering into a long point, and 

 more abruptly rounded to the petiole; the middle nerve is broader, and the 

 secondary veins more; distinct, in a more acute angle of divergence. The size 

 of these leaves is very variable, at least for the length, one of our fragments 

 exposing a leaf of about fourteen centimeters long, while the other specimen 

 is of a leaf preserved entire, and measuring only six and a half ccnlimelcrs, 

 though scarcely broader. Another specimen of the same sj)ecies and from 



