288 UNITED STATES GEOLOGICAL SUKVEY— TERTIARY FLORA. 



])ar;iblc to Uiis one. Tlie specimen represented in fig. 0, a mere fragment 

 from another locality, is somewhat diirerent hy the lateral nerves more 

 evidently branching and more oblicpie. The lower veins of fig. h have, 

 however, the same characters. Th(! specimen representc'd in fig. 10 has the 

 lower lateral nerves more open, a diiierence unimportant in the determina- 

 tion of species of Juglai/s. 



Habitat. — Green Itiver, Wyoming, above fish-beds {Dr. F. Y.IIaydeii). 

 The fragment represented in. fig. *J is irom Golden, Colorado. It may 

 belong lo a differeut sjx'cies. 



§ 2. — Lenjlets ricuafe or dentate. 



J II i; I a (I s a I k u 1 i II a , Leeqx. 



rialc LXII, rigs. G-y. 



Jiiglann alkalina, Lesqx., Annual Roport, 1874, p. ?>08. 



Leaves lanceolate, acuminate, rounded or narrowed in a curve to a short petiole ; borders creuu- 

 late; lateral veins distant, mostly alternate, parallel, curved iu passing toward the borders, ascending 

 Ligli along them in simple festoons, separated by short intermediate tertiary veins; nervilles m right 

 angle, strong; areolatiou irregulaily ijuadrate. 



Tliis species, very fine and dislinct, is related, by the facies of the leaves, 

 to the Juglanditcs of the Suzanne Flora, which have, however, a different 

 character of nervation. The American leaves have llu; lateral nerves more 

 distant, and their base is not narrowed in the same degree. They are, 

 moreover, mnch smaller, from five to twelve centimeters long and from two 

 to four centimeters broad. This species is also comparable to .7. bi/inica, 

 Ung., presenting, however, the same kind of difl'erencc in the more distant 

 and more oblitpxe lateral nerves, ascending higher along the borders, which 

 are merely crenulate and not denticulate. As seen iroin the figures, the 

 leaves are more or less unequal at tlie l>ase, and more or less narrowed 

 or rounded to the petiole; l)ut they do not diU'er in the essential characters. 

 Variations of the same kind are generally observed upon leaflets of the 

 same species ol' Jug/ans and Canja. The bows along the l)orders are not 

 comieclcd with the teeth by nervilles. 



IIaiutat. — Alhali Station, Wyoming {Wm. Clchurn). 



