MIOCENE FLORA— BAD LANDS. 225 



Populus Z a d d a c li i , Heer. 

 "U. S. Geol. Rep.," vii, p. 176, pi. xxii, fig. 13. 



Hah. — A fine specimen from Little Missouri Valley, Dakota, is in the 

 collection of Professor Winchell. It has the same character as the, leaf, 

 pi. xxxi, fig. 8, of this volume. 



Populus arctica, Heer. 



Plate XL VI, Figs. 2-13. 



"U. S. Geol. Rep.," vii, p. 178, pi. xxiii, figs. 1-G. 

 Populus decipiens, Lesqx., Ibid., p. 179, pi. xxiii, fig9. 7-11. 



I have formerly separated, under the name of P. decipiens, leaves with 

 characters of nervation identical with those of P. arctica, but differing gen- 

 erally by the borders being very entire, the pattern more enlarged in the 

 middle, the base cuneate and the size smaller. But though generally the 

 leaves of P. arctica as figured by Heer have the borders undulate, even 

 obtusely dentate, they are sometimes perfectly entire, and fig. 5 of pi. xlvi, 

 which has undulate borders and is evidently referable to P. arctica, is a 

 leaf still smaller than some of those of the same plate representing P. 

 decipiens, which I now admit as a variety. The leaves of both forms are 

 found together. All those figured here are from the Bad Lands, in the 

 collections of Professors Denton, McBride, and Winchell. 



Populus cuneata, Newby. 

 Plate XLVI A, Fig. 5. 

 Newby., 'Ext. Fl. of N. A.," p. 64; "Illustr.," pi. xiv, figs. 1-4. 



Leaves small, obovate, narrowed in rounding or cuneate to the base, generally 

 round or truncate obtusely dentate in the upper part, rarely narrowed into a short 

 blunt point, entire from the middle, five or seven palmately nerved from the base, 

 loug-petioled ; lateral nerves curving in ascending, branching outside. 



This species has the character of P. arctica in all except the size of 

 the leaves, the coarse denticulation of the generally flat, even emarginate 

 apex. The base is sometimes rounded as in the leaf I have figured, but 

 in others it is exactly wedge-shaped. 



Hab. — Bad Lands of Dakota. Denton's and McBride 's collections. 



CF 15 



