GENERAL REMARKS. 



The number of species enumerated and described from this group is 

 228; of these Florissant has the largest number (152), while from the 

 Green River Station 24 species only have been determined from specimens 

 obtained in a cut of the railroad just above the station, and which, of 

 course, represent the Flora of the Green River Group. Of the other local- 

 ities, I have found 15 species in the specimens from Elko, 14 in those from 

 Randolph County, Wyoming, 7 in those from Alkali Station, 6 in those 

 obtained near the mouth of the White River, and of the other localities 

 marked in the table two or three only in each. 



With these materials it is not well possible to determine, from a com- 

 parison of the plants of each place, the degree of relation of the local 

 vegetable groups, and, therefore, a table of distribution does not seem of 

 great value for that purpose. It is, however, important to record the data, 

 which may help to trace the march of the vegetation on the American 

 continent during the Tertiary ; to see also if the different localities, which 

 I formerly referred to the same stage, show traces of identity in the char- 

 acters of their plants and at the same time to fix, if possible, the age of 

 the very interesting vegetable group of Florissant by its affinity with some 

 local Flora of Europe. And as this volume is, most probably, the last 

 which I shall have opportunity to prepare on Tertiary plants of Western 

 America, I think proper to leave all the materials which have been examined 

 thus far, exposed as clearly as possible for future comparison. 



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