34 FOSSIL PLANTS FROM MONTANA KXOWLTON. 



the mouth of the YeUow.stone, and on the Yellowstone, at O'Fallon's 

 Creek, 100 miles above where the Yellowstone joins the Missouri, and 

 in the valley of the Yellowstone between this point and its month. 



Much additional material from the same general region AA'as obtained 

 by Dr, C. A. White and Trof. Lester F. Ward, of the present Geological 

 Survey, during- the years 1881-1883. Prof. Ward's material came from 

 the Y'ellowstone in the vicinity of Glendive, ]\Iont., and the results of a 

 preliminary examination of it arc published in the Sixth Annual He- 

 port by the Director for the year 1884-'85 (pp. 512 et seq.) and also as 

 a special bulletin (Types of the Laramie Flora, Bull. U. S. Geological 

 Survey No. 37). Prof. Ward's material, it will be observed, is from 

 practically, the same region as nuich of that obtained by Dr. Ilaydcn, 

 and, as shown both by the matrix and by the species represented, some 

 of the material must have come from practically the same spot. 



DESCRIPTION OF THE SPECIES. 



Thuya iutemipta Ntnvlty. 



Later Extinct Floras, p. 42 ; Illustrutious of Cret. and Tert. Plants. PL xi, Figs. 5, 5a. 



This beautiful species has not before been obtained, so far as I know, 

 since the original specimens were collected by Dr. Hayden, near Fort 

 Union. The slab obtained by Prof. Meeds bears a single small, but 

 highly characteristic branch of this conifer. 



Popxilus Meedsii, sp. nov. 

 PL I. Figs. 1, 2. 



Leaves short-pctioled, 12 to liO"^'" hmg, 3 to 7*^"^ broad, long-lanceolate, 

 usually being broadest in the middle, from which point they taper grad- 

 uall}- downward into a wedge-shaped base and upward into a similarly 

 shaped, rather acute apex; lower third of margin smooth, remainder 

 provided with very short outwardly pointing teeth separated by shallow 

 sinuses; midrib strong, straight; secondaries, 12 to 14 pairs, alternate 

 or subopposite, emerging at an angle of 15° or 50°, running straight 

 toward the margin, along which they arch, forming a nearly regular 

 series of quadrangular meshes, and from which slender branches enter 

 the weak teeth ; tertiaries strong, forming lattice-like bars nearly at 

 right angles to the midrib or in some cases more nearly at right angles 

 to the secondaries; ultimate nervation fine, quadrangular. 



This beautiful species, which I take pleasure in naming in honor of 

 Prof. Meeds, the collector, seems to find its nearest living analogue 

 in Populm angustifol'm James (i*. halsamifera var. angmtifolia Watson), 

 a species still living along streams from New Mexico and Colorado to 

 California and Waslungton. The living species ditlers merely in hav- 

 ing the leaves more nearly ovate-lanceolate and in being < rcnate-serrate 

 with numerous fine teeth. The nervation is quite similar in both, being, 

 however, less regular and with the secondaries at a more acute angle 



