LATER CRETACEOUS AND KAINOZOIC. 215 



of the United States, and of the so-called Miocene of 

 McKenzie Eiver and Greenland, and that the whole are 

 Paleocene ; and this conclusion has now been confirmed 

 by the researches of Gardner in England, and by the dis- 

 covery of true Lower Miocene beds in the Canadian north- 

 west, overlying the Laramie or lignite series. 



In a bulletin of the United States Geological Sur- 

 vey (1886), Dr. White has established in the West the 

 continuous stratigraphical succession of the Laramie and 

 the Wahsatch Eocene, thus placing the Laramie con- 

 formably below the Lower Eocene of that region. Cope 

 has also described as the Puerta group a series of beds 

 holding vertebrate fossils, and forming a transition from 

 the Laramie to the Wahsatch. White also testifies that a 

 number of fresh -water mollusks are common to the Wah- 

 satch and the Laramie. This finally settles the position 

 of the Laramie so far as the United States geologists are 

 concerned, and shows that the flora is to be regarded as 

 Eocene if not Upper Cretaceous, in harmony with what 

 has been all along maintained in Canada. An important 

 resume of the flora has just been issued by Ward in the 

 bulletins of the United States Geological Survey (1887). 



Before leaving this part of the subject, I would depre- 

 cate the remark, which I see occasionally made, that fossil 

 plants are of little value in determining geological hori- 

 zons in the Cretaceous and Tertiary. I admit that in 

 these periods some allowance must be made for local 

 differences of station, and also that there is a generic 

 sameness in the flora of the northern hemisphere, from 

 the Cenomanian to the modern, yet these local differ- 

 ences and general similarity are not of a nature to in- 

 validate inferences as to age. No doubt, so long as 

 palaeobotanists seemed obliged, in deference to authority, 

 and to the results of investigations limited to a few Eu- 

 ropean localities, to group together, without distinction, 

 all the floras of the later Cretaceous and earlier Tertiary, 



