FLORA OF THE GREEN RIVER GROUP. 171 



Fraxinus Cngcri, sp. nov. 



Leaflet small, membranaceous, very entire, unequilateral, broadest below tbe mid- 

 dle, ovate lanceolate, acuminate, narrowed to a short petiole. 



There are three leaflets of the same kind remarkably similar in shape 

 and size to Fraxinus primigenia, Ung., "Syllog.," i, p. 22, pi. viii. figs. 3-8. 

 They are 41 to 7 centimeters long, II to 2h centimeters broad below the 

 middle, where they are much larger on one side than the other. The sec- 

 ondary nerves are parallel, open, curved in traversing the areas, branch- 

 ing near the borders, effaced in touching them. It may be the same species 

 as that of Unger, but it is not possible to ascertain the degree of relation- 

 ship, as in the leaflet representing the European species the secondary 

 nerves are neither described nor distinctly figured. 



Hah. — Florissant. Lacoe's Cabinet, No. 57. 



Fraxinus Brownellii, Lesqx. 

 "U. S. Oeol. Rep.," vii, p. 230. 



Fraxinus Libbeyi, ep. nov. 



Plate XXVII, Figs. 5-7, 9. 



Leaves very variable in size, unequilateral, ovate-lanceolate, acuminate, rounded 

 to a short petiole, irregularly serrate; secondary nerves parallel, close, 10 to IS pairs 

 according to size, branching near the borders, camptodrome, joined to the teeth by 

 anastomosing veinlets. 



The leaves vary from 31 to 11 centimeters long, 1£ to 4 centimeters 

 broad. They are very unequal at base, generally cut straight and obliquely 

 on one side toward the petiole, enlarged and rounded on the other, deeply 

 more or less irregularly serrate. Fig. 9 represents a long narrow leaf, 

 broader in the middle, gradually narrowed upward and downward, rather 

 oblong; the other leaves are broader toward the base and ovate; the 

 secondary nerves are more or less divided near the borders, generally 

 camptodrome, joined to the teeth by nervilles, a few of them entering the 

 teeth; the nervilles are parallel, flexuous, simple or forking, or anasto- 

 mosing at right angles in the middle; the areolation as seen in fig. 9 is 

 formed of very small quadrate or round-quadrangular meshes. 



jy a j —Florissant. Princeton Museum, Nos. 217, 245, 275, 281. 



