KNOWI/TON] KOOTANIF PLANTS FROM GREAT FALLS, MONTANA 123; 



to agree best with certain species of Zamites, it was referred pro- 

 visionally to this genus. 



According to Heer, Saporta, and others, the leaflets in Zamites 

 are inserted on the upper surface of the rachis and are more or less 

 contracted or inequilateral at base. In Pterophyllum the narrow 

 leaflets are attached, usually at a right angle, by their entire bases 

 to the edge of the rachis and are free throughout. 



The. present collection contains two well preserved specimens, one 

 of which fortunately shows' the upper surface of the leaf, and from 

 this it is ascertained that the leaflets are attached by their bases to 

 the edge of the rachis, thus throwing the species into Pterophyllum, 

 to which I have accordingly transferred it. The two specimens here 

 mentioned are preserved in small nodules, which when broken open 

 exhibit nearly the complete leaf in an admirable state of preserva- 

 tion. 



There are also several examples preserved in a soft shale that 

 seem to belong here. They have, as may be seen from the figure,, 

 slightly narrower and rather more acuminate leaves, but the differ- 

 ence is probably too slight to warrant separating them. As a mat- 

 ter of fact, they do resemble Heer's Zamites speciosus 1 about as 

 closely as the present species, but there is no evidence to show that 

 the leaflets are not attached along the side of the rachis, and, more- 

 over, the nervation, said by Heer to be obsolete in his Z. speciosus, 

 is the same as in Pterophyllum montanense. 



Locality. — Flood siding 6 miles southwest of Great Falls, Mon- 

 tana [at or near type locality]. Collected by Prof. O. C. Mortson,. 

 Spanish Coulee, 12 miles east of Cascade, Montana. 



NILSONIA SCHAUMBURGENSIS (Dunker) Nathorst 



Nilsonia schaumburgensis (Dunker) Nathorst, Anzeiger d. k. Akad. d. 

 Wiss. in Wien, Jahrg. 26, 1889, p. 237; Fontaine in Ward, Monog. 

 U. S. Geol. Survey, No. 48, 1905 [1906], p. 303, pi. lxxii, figs. 17-21. 



The specimens obtained at Geyser are discussed at length by Pro- 

 fessor Fontaine, and the present specimens add nothing of interest. 



Locality. — Meridith mine, 3 miles southeast of Nollar's ranch and 

 6 miles southwest of Geyser, Cascade County, Montana. 



Fl. Foss. Arct., vol. 3, 1874, p. 64, pi. xiv, figs. 1-12; pi. xvi, fig. 4. 



