[pENHALLow] NOTES ON TERTIARY PLANTS 3S 



associated with Cretaceous marine animal remains botli in Dakota and 

 in Vancouver's Island, we should be inclined to assign them at least 

 to the base of Eocene. In my judgment, any precise decision as to 

 ■^heir geological age is premature, and it is rash to identify the beds, 

 on the evidence of plants alone, with particular subdivisions of the 

 ■'tertiary elsewhere, .... but in the meantime, it is sufficient 

 to hold that we have here a flora which in Europe would be regarded 

 as miocène, but which in America probably began to exist at ai much 

 -earlier date." ^ 



In a more recent revision of the flora of this region, however,- 

 this statement was subject to some modification, since " the truth 

 appears to be that they constitute a transition from the upper part 

 of the Cretaceous to the Eocene, ^and that the analogies which have 

 been sought to be established between them and European Miocene 

 «deposits are altogether fallacious, and based upon the similarity of an 

 American flora of early Eocene date with one found in Europe at a 

 later period.* This opinion is later confirmed on the basis of data 

 advanced by Newberry and Lesquereux, and it is accepted as established 

 that the Porcupine Creek and the Great Valley Groups are equivalent 

 to the Souris Eiver beds, and that they lie above the Willow Creek 

 Series which defines the transition from the Middle Laramie or Upper 

 Cretaceous, to the Upper Laramie or Eocene.^ 



From a stratigraphical study of the series at Porcupine Creek 

 and at Great Valley,'* the "late Dr. G. M. Dawson was also led to place 

 these deposits in the Eocene. Since that time but little new evidence 

 has been offered with respect to their age, but such as it is, it serves 

 to confirm previous conclusions. In 1881 Mr. R. G. McConnell, of 

 the Geological Survey, examined the entire region, and in his report 

 published in 1882, he states that " the Porcuipine Hills consist of 

 Tocks forming the upper part of the Laramie and mark the axis of a 

 wide synclinal."^ In a letter recently received from IMr. J. F. Whit- 

 eaves, Mr. McConnell is quoted as saying that "' these beds are undoubt- 

 edly above the Willow Creek Series, and that, so far as known, they 

 overlie it conformably." 



' B. N. A. Bound. Comm., 1875. App. 327-328. 

 '' Trans. R. Soc. Can., I., iv., 15, 16, 1882. 

 ^ lUd., IV., iv., 19, 20, 1886. 



* Ihid. 93-100. 



* Kept. Geol. Surv. Can., 1882. IOC, 96C, 106C, 112C, 113C. 



