ON FOSSIL rLANïS. 71 



of Europe as high as the Miocene of Oeuingeu, and is found in the leaf beds of 

 Mull, that is if, as seems likely, the P. Hebridicus of Forbes is this species. It also 

 occurs at Atanekerdluk in Greenland, in Iceland and in Spitzbergen. 



It seems probable that P. Gvlielmœ, Goept, is merely a variety. It occurs with 

 the former in Switzerland and Greenland. Farther, Schimper suggests that P. 

 Raynoldsii and P. Haydenii^ of Lesquereux, both Upper Laramie species, and found 

 plentifully in the sandstones on Cow^ River, near Calgary, may be varieties of this 

 somewhat variable species. 



POPULUS ARCTIC.4., Heer. {V\. X, Figs 2, 3 & 4.)— This is much the most abundant species 

 in Mr. McCounell's collection, and seems to show that then, as now, this genus was 

 dominant. This is an European as well as American and Greenland species, and 

 presents a great variety in the size and forms of the leaves, which have gi^'en rise 

 to the formation of several species. Mr. McCouneH's specimens show a great 

 number of gradations in form, from broad oval to a very broad reniform, and in size 

 from one inch to four in diameter. Its occurrence in the Laramie of Western 

 Canada is noticed in my paper as Laramie Plants, (Trans. Eoy. Soc. Can., 1886). 



There seems to be some uncertainty as to the reference of this leaf to Popidus. 

 Saporta, thinks that it may really be a Menospermum allied to the modern M. 

 virginiam. If a poplar, it is remarkable that its nearest living ally seems to be P. 

 Euphratica of the banks of the Euphrates and Jordan. 



PoPULUS HooKERi, Heer. (PI. X, Fig. 5).— This species, found thus far only at Mackenzie 

 Eiver, has small leaves, resembling those of P. arc/ica in form, but differing some- 

 what in venation, in which it approaches slightly to P. tremuloides, the common 

 aspen. " 



PoPULUS RiCHARDSONil, Heer. — A large and fine species, quite different from the preced- 

 ing, and allied to the modern aspens. It is found in the Fort Union Laramie of the 

 United States, and in the Greenland and Spitzbergen collections, also in Canada 

 in the Upper Laramie, on Bow Ttiver. Its nearest relation in modern Canada is P. 

 grandidentata, the great-toothed aspen, the leaves of young shoots of which species 

 greatly resemble those of the ancient form. - 



CORYLUS McQuARRii, Pories.— This species is found in the Mull leaf-beds and elsewhere 

 in Europe, also in Alaska, Iceland, Spitzbergen and Greenland, and in the Upper 

 Laramie of the western plains, both in Canada and the United States, though it 

 seems to be less common than further north. Further south than Mackenzie 

 Eiver, this species is associated with leaves not distinguishable from those of the 

 modern hazel, C rostrata.' 



NoBDENSKoLDiA BUREAUS, Heer. (PI. X, Fig. 6).— This is a beautiful fruit, divided into 

 lobes at top, and supposed to be allied to Tiliaceae. The.se fruits occur in Greenland 

 and Spitzbergen, and have been discovered by Mr. McConnell for the first time in 

 Canada. It is by some referred to the genus Cistus or to Dioxpyros. 



' Fossil Plants of Laramie, Trans. R. S. C, 1886. ' Ibid. 



