244 



THE GEOLOGICAL HISTORY OF PLANTS. 



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distributed ; and these show that further subsidence or 

 denudation in the north had opened a way for the arctic 

 currents, killing out the warm-water animals of the Nio- 

 brara group, and filling up the Mediterranean of that 

 period. Of the flori* of these Upper Cretaceous periods, 

 which must have been very long, we know something in 

 the interior regions, from the discovery of a somewhat , 

 rich flora in the Dunvegan beds of the Peace River dis- 

 trict, on the northern shore of the great Cretaceous Medi- 

 terranean;* and on the coast of British Columbia we 

 have the remarkable Cretaceous coal-field of Vancouver 

 Island, which holds the remains of plants of modern 

 genera, and, indeed, of almost as modern aspect as those 

 of the so-called Miocene of Greenland. They indicate, 

 however, a warmer climate as then prevalent on the Pa- 

 cific coast, and in this respect correspond with a peculiar 

 transition flora, intermediate between the Cretaceous and 

 Eocene or earliest Tertiary of the interior regions, and 

 which is described by Lesquereux as the Lower Lig- 

 nitic. 



Immediately above these Upper Cretaceous beds we 

 have the great Lignite Tertiary of the West — the Laramie 

 group of recent American reports — abounding in fossil 

 plants, at one time regarded as Miocene, but now known 

 to be Lower Eocene, though farther south extending up- 

 ward toward the Miocene age.f These beds, with their 

 characteristic plants, have been traced into the British 

 territory north of the forty-ninth parallel, and it has been 

 shown that their fossils are identical with those of the 



* " Reports of Dr. G. M. Dawson, Geological Survey of Canada." Also, 

 " Transactions of the Royal Society of Canada," vol. i. 



f Lesquereux's " Tertiary Flora " ; " White on tlic Lar<imie Group " ; 

 Stevenson, "Geological Relations of Lignitic Groups," American Philo- 

 sophical Society, June, 1875; Dawson, "Transactions of the Royal So- 

 ciety of Canada," vol. iv. ; Ward, " Bulletin of United States Geological 

 Survey." 



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