lesquereux.] EVIDENCE OF AGE OF LIGNITIC GEOllP. 287 



Tertiary division, separated at its base under the name of Paleocene. 

 Three are identified and two analogous, in the flora of Golden. Nine 

 identical and one analogous, in that of Black Butte 5 and four have an- 

 alogy with Cretaceous forms. 



The relation of Point of Rocks with the Canadian Tertiary is especially 

 marked by Lemna scutata, a floating plant, described by Prof. J. W. 

 Dawson, in the report of the geology and resources of the region in the 

 vicinity of the forty-ninth parallel. The geologist of the commission, 

 Prof. George Mercer Dawson, obtained the specimens from abed of clay 

 near the very base of the Lignitic formation, where, according to the in- 

 formation kindly furnished to me, the vegetable remains representing 

 this species were very abundant, but difficult to get from the crumbling 

 shale. Though their reference to any living species is not distinctly 

 marked, the peculiar character of the plants does not permit any doubt 

 about its identity with that of Point of Rocks, which is also represented 

 by numerous specimens. Half the specimens from this place bear re- 

 mains of this species and of another, Pistia corrugata, which may be a 

 mere form of the same. In regard to the identity of the Lignitic meas- 

 ures of Canada with those of the United States, the evidence is equally 

 conclusive. The report quoted above proves it, by good sections and 

 diagrams, which indicate the same distribution of Lignitic beds, clay, 

 and sandstone strata, as in the great Lignitic of the Rocky Mountains, 

 of which that of Canada is a mere continuation. It enumerates, also, 

 besides those which are descirbed, a number of plants from the Lower 

 Tertiary, of a higher stage, mostly of Miocene types. 



In remarking upon the fossil plants which he had to determine, the 

 celebrated professor of Montreal, J. W. Dawson, says, " That the plants 

 of the first group are for the most part identical with those found by 

 American geologists, in the Fort Union series, and which have been de- 

 termined by Professor Newberry and by M. Lesquereux. They are 

 also similar to plants collected by Dr. Richardson, in the Lignitic series 

 of the Mackenzie River, as described by Heer, and represented by speci- 

 mens in the collection of the geological survey, &c. They also approach 

 very closely the so-called Miocene floras of Alaska and Greenland, as 

 described by Heer, and in their facies, and in several of their species, 

 they coincide with the Miocene floras of Europe." He then adds, " If 

 we were to regard the affinities of the plants merely, and to compare them 

 with the Miocene of other countries, and also to consider the fact that 

 several of the species are identical with those still living, and that the 

 whole facies of the flora coiucides with that of modern temperate Amer- 

 ica, little hesitation would be felt in assigning the formation in which 

 they occur to the Miocene period. On the other hand, when we consider 

 the fact that the lower beds of this formation hold the remains of rep- 

 tiles of Mesozoic types ; that the beds pass downward into rocks hold- 

 ing Baculites and Inocerami; and that a flora essentially similar is found 

 associated with Cretaceous animal-remains, both in Dakota* and Van- 

 couver's Island, we should be inclined to assign them at least to the base 

 of the Eocene. 



From this it seems that Professor Dawson does not separate the two 

 essential groups of the Tertiary: the upper one with its Miocene types, a 

 flora indicating a temperate climate like that of the middle zone of the 

 United States ; the lower one with its numerous species of Palms, of Ficus, 

 &c, evidently representing a subtropical vegetation. In this last flora, 

 the one which is now under examination in this paper, there is no 

 species identical or analogous to any of those of the Dakota group. 



* The assertion is right for Vancouver's Island but not for the Dakota group. 



