SROMION IV., 1886. Pp ae | Trans. Roy. Soc. CANADA. 
III. On the Fossil Plants of the Laramie Formation of Canada. 
By Sir J. Witu1am Dawson, C.M.G., LL.D., FRS. 
(Presented May 27, 1886.) 
I. —INTRODUCTORY. 
The following paper is a continuation, and in so far a completion, of those on the 
Mesozoic Floras of Canada contained in Vols. I and III of these Transactions. 
On the geological map of Canada, the Laramie series, formerly known as the Lignitic 
or Lignite Tertiary, occurs, with the exception of a few outliers, in two large areas west of 
the 100th meridian, and separated from each other by a tract of older Cretaceous rocks, 
over which the Laramie beds may have extended, before the later denudation of the 
region. 
The most eastern of these areas, that of the Souris River and Wood Mountain, 
extends for some distance along the United States boundary, between the 102nd and 
109th meridians, and reaches northward to about thirty miles south of the “elbow” of the 
South Saskatchewan River, which is on the parallel of 51° north. In this area, the lowest 
beds of the Laramie are seen to rest on those of the Fox Hill group of the Upper Creta- 
ceous, and at one point on the west they are overlaid by beds of Miocene Tertiary age, 
observed by Mr. McConnell, of the Geological Survey, in the Cypress Hills, and referred 
by Cope, on the evidence of mammalian remains, to the White River division of the 
United States geologists, which is regarded by them as Lower Miocene.’ The age of 
the Laramie beds is thus stratigraphically determined to be between the Fox Hill Creta- 
ceous and the Lower Miocene. They are also undoubtedly continuous with the Fort 
Union group of the United States geologists on the other side of the international 
boundary, and they contain similar fossil plants. They are divisible into two groups,— 
a lower, mostly argillaceous, and to which the name of “ Bad Lands beds” may be given 
from the “ bad lands” of Wood Mountain where they are well exposed, and an upper, 
partly arenaceous member, which may be named the Souris River or Porcupine Creek 
division. In the lower division are found reptilian remains of Upper Cretaceous type, 
with some fish remains more nearly akin to those of the Eocene.” Neither division has 
as yet afforded mammalian remains. 
The western area is of still larger dimensions, and extends along the eastern base of 
the Rocky Mountains from the United States boundary to about the 55th parallel of 
latitude, and stretches eastward to the 111th Meridian. In this area and more especially 
in its southern part, the officers of the Geological Survey of Canada have recognized three 


' Report of Geol. Survey of Canada, 1885. ? Cope in Dr. G. M. Dawson’s Report on 49th parallel. 
