46 DESCEIPTIOX OF SPECIES. 



Heer, with base and top also destroyed. The midrib is narrow, the second- 

 ary veins thin, the lower pair at a more acute angle of divergence; but the 

 divergence of those above is gradually more obtuse, not abruptly so, as is 

 the leaf of the "Phyllites." The veins are close, 5 to 6 millimeters dis- 

 tant, not decurring to the medial nerve, slightly arched in passing up 

 toward the borders, which they follow in curves, anastomosing by nervilles 

 at right angles with the anterior veins. 



The other specimen bears the impression of the under surface of a leaf 

 and the upper part of two others, these tapering into a long acumen. The 

 areolation is very distinct, exposing a coarse reticulation composed of large, 

 irregularly quadrate areas divided into small polygonal meshes. 



These leaves have great affinity to those of the following species ; they 

 differ by their shape, oblong in the middle, by the secondary veins being 

 more distinct, especially near and along the borders; the areolation 

 appears to be of the same character. 



Hab. — South of Fort Barker. Chs. Sternberg. 



Ficus Halliana, Lesqx. 

 " U. S. Geol. Kep.," ri, p. 68, pi. xxviii, figs. 3, 9. 



Ficus Beckwithii, sp. nov. 

 Plate XVI, Fig. 5; XVII, Figs. 3, 4. 



Leaves sub-coriaceous, lanceolate or oblong, very entire, narrowed upward to a 

 long acumen, more rapidly downward from below the middle and slightly decurring to 

 the petiole; midrib strong, gradually thicker toward the base; secondary veins numer- 

 ous, parallel, camptodrome; nervilles close, flexuous, and sub-continuous, at right 

 angles to the veins. 



This species is of the same type as F. protogcea, Heer, "Fl. Arct.," iii, 

 p. 108, pi. XXX, figs. 1-8, differing by the form of the leaves, which in 

 F. protogaea are oblanceolate or largest toward the apex. The veins are 

 closer, though at the same angle of divergence, simple, 7 to 8 millimeters 

 distant, at an angle of divergence of 35°. The nervilles also are very close 

 and distinct. The leaves average 15 centimeters in length and 3J to 4 

 centimeters broad below the middle. 



Hab. — Near Morrison, Colorado. H. C. Beckwith. 



