FLORA OF THE DAKOTA GROUP. 37 



CUPTJLIFER^E. 



FAGUS, Tourn. 



Fagus polyclada, Lesqx. 



"D. 8. Qeol. Rep.," Ti, p. 67, pi. v, fig. 6. 



Fagus cretacea, Newby. 



Plate n, Figs. 6, 60. 

 Newby., "Notes on Ext. PI.," p. 23; "Illustr.," pi. ii, fig. 3. 



Leaf oval, entire, slightly narrowed to the petiole ; lateral veins sharply defined, 

 numerous, parallel, craspedodrome, the points of the nerves being prominent and the 

 intervals between them forming shallow sinuses. 



To offer a point of comparison between this leaf and the one described 

 as Fagxis polyclada I have figured it again, distinctly tracing the nervilles, 

 which are not visible on the original figure. The type of venation is that 

 of Fagus not of Rhamnus; the marginal veinlets only are more distinct 

 than in F. ferruginea, following the border in short curves anastomosing to 

 the upper nervilles, nearly as in Castanea. 



Hab. — Smoky Hill, Kansas. Dr. F. V. Hayden. 



DRYOPHYLLUM, Debey. 



Leaves lanceolate or oblong, generally dentate, penninerve; secondary nerves (in 

 denticulate leaves) sub-opposite, straight, simple, entering the teeth directly by their 

 points, or more rarely branching quite near the borders, one of the divisions entering 

 a tooth, the other curving under, following the margins in wavy flexures and joining 

 the next vein above. In the entire leaves the secondary nerves are more or less curved, 

 camptodrome, with nervilles transversely decurrent, simple or forking, united by venules 

 at right angles. (Sap.) 



Saporta in describing the genus compares the species referred to it to 



some kinds of Oaks and Chestnuts with coriaceous leaves, now inhabiting 



the mountains of Asia and of Mexico, and which seem to have been the 



ancestors of the Oaks and Chestnuts of the present Flora of North America. 



Dryophyllum (Quercus) primordiale, Lesqx. 

 "U. S. Geol. Rep.," ri, p. 64, pi. v, fig. 7. 



Dryophyllum (Quercus) latifolium, Lesqx. 

 Plate IV, Figs. 1, 2. 

 Hayden's "Ann. Rep.," 1874, p. 340, pi. vi, fig. 1. 



Leaf large, broadly ovate, rounded at base, deeply sinuate, obtuse or blunt at 

 the apex ; medial nerve thick ; secondary nerves distant, straight or slightly curving 

 up to the borders, the lower more or less branching. 



