344 UNITED STATES GEOLOGICAL SURVEY— TERTIARY FLORA. 



Of the thirty species enumerated in the table, two appear identical with, 

 and one isTclatedto Canadian species, recognized as Tertiary, as seen below 

 from qnotations of Prof G. M. Dawson's report. Six arc identical with, and 

 seven are analogous to, those of the Lower European Miocene; two are iden- 

 tical with, and one allied to, Arctic Miocene species. Seven have a close 

 relation to plants of the Lower European Eocene, S(^zanne and Gelinden, 

 two localities composing a subdivision separated at the base of the Tertiary, 

 under the name of Paleocene. Three are identified and one analogous in the 

 flora of Golden; nine identical and one analogous in that of Black Buttes; 

 and four have analogy 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 spcicimens from a bed of clay near the very base of the 

 Lignitic formation, where, according to the information kindly furnished to me 

 the vegetable remains representing the species were very abundant, but diffi- 

 cult to separate in their integrity from the crumbling shale. Though not posi- 

 tively determinable, on account of the indifferent state of preservation of the 

 specimens, this plant has such an analogy of characters with the one described 

 under this name from Point of Rocks, that, being found in the same circum- 

 stances of habitat, I consider as positive the identity of both forms. The 

 species is also represented at Point of Rocks by numerous specimens, for one- 

 half of those received from this place bear remains of it, and of another, 

 Pistia corrvgata,\vh\ch may be a mere form of the same. The Tiapa leaves 

 of Point of Rocks are correlated by fruits considered by Prof Dawson as 

 referable to this genus, and which were found at the same locality as the 

 Lemna. 



In regard to the identity of the Lignitic measures of Canada with those 

 of the United States, the geological evidence is conclusive. The report 

 quoted above proves it by good sections and diagrams, which expose the same 

 distribution of lignite 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 described, a number of plants 

 from the Tertiary strata, of a higher stage apparently, for they- mostly are of 

 Miocene types. 



