82 SIE J. WILLIAM DAWSON ON THE 



continental elevation with climate somewhat extreme, then the subsidence which allowed 

 the warm waters of the equatorial current to circulate through the interior basin of the 

 continent would restore warmth and humidity, and would afford the climatal conditions 

 favourable to the introduction of a new and more varied flora and allow this to 

 extend far to the north. Such a state of affairs would also afford the local causes neces- 

 sary to the formation of the coals which characterize the Lower Cretaceous, and which, 

 folded up and altered in the great earth-movements of the Tertiary period, constitute beds 

 of true anthracite in the Queen Charlotte Islands and in the Rocky Mountains. 



IL — Eecent Collections of Plants from the Kootanie Formation. 



The collections now under consideration were made in 1891 by Mr. H. M. Ami, F.G.S., 

 at Anthracite, and by Dr. Hayden at Canmore, both places being situated in the Cascade 

 Coal Basin of the Rocky Mountains. ' Those from the latter place are limited to a few 

 specimens in a dark gray shale. The Anthracite specimens are in a black shaly rock 

 much jointed, with frequent slickensided surfaces and liable to break across the bed- 

 ding. The fossils are represented by shining anthracitic films on the black matrix, and 

 the more delicate leaves can be distinctly made out only in a favourable light. These 

 peculiarities of preservation oppose considerable difficulties to their comparison with 

 the fossil plants from other and less disturbed districts, and in the following descriptive 

 list some allowance has been made for them in the identifications proposed with species 

 from the Potomac and other formations. It is also to be remarked that though from 

 the same formation which afforded the plants described in 1885, few of the species are 

 identical. This may indicate some dilFerence of horizon within the formation, or may 

 depend on local differences, or on the fragmentary and imperfect nature of the collec- 

 tions. In any case it is plain that the collections hitherto made must very imperfectly 

 represent the flora as a whole, either in number of species or in the completeness 

 of the specimens. Hence the present notes must be looked upon as merely provisional 

 and introductory, and their presentation to the Society is justified only by the great geo- 

 logical importance of the facts which, however imperfect from a palœobotanical point of 

 view, they serve to indicate. 



I may be permitted to add that the history of geological discovery in the Canadian 

 North-west affords a convincing proof of the value of fossil plants when carefully 

 collected with reference to the containing beds, in determining the geological ages of the 

 formations in which they occur, while there can be no question of their paramount value 

 in indicating geographical and climatal conditions. 



Annual Kept. Geo). Surv. Can., 1885, p. 126 B. 



