THE EOCENE OF NORTH AMERICA 



447 



Union, and that name is therefore adopted for the formation." 

 A section is given showing Fort Union beds to be 4648 feet 

 thick at this place. "The importance of this section, which is 

 the only one known to the writer in which the Fox Hills, Lara- 

 mie, Livingston, and Fort Union formations occur superimposed,, 

 is apparent when it is considered that in eastern Montana and 

 Canada the Fort Union rests directly upon Laramie beds in 

 apparently perfect conformity." 1 Vertebrate fossils were not. 

 found, but the invertebrate fossils from the Fort Union beds at 

 this place were submitted to Stanton, who reported that "almost 

 all the species of the list were originally obtained near Fort 

 Union on the Missouri River." 2 



Of Fort Union fossils in the United States National Museum,. 

 Weed says 3 : "They have been studied by Professor Knowlton, 

 who reports that the Fort Union flora embraces 169 species.. 

 Of this number 130 species are confined to this formation. Of 

 the 39 species found in other terranes, 21 occur in the Mio- 

 cene, 14 in the Denver (post-Laramie), and 9 in the Laramie.. 

 These figures tell their own story." Knowlton states that the 

 flora as a whole is clearly Eocene. This confirms the statement 

 of Newberry that the floras of the Laramie and the Fort Union 

 are totally distinct, "and that these formations should be referred 

 to different geological horizons, the Fort Union to the Tertiary,, 

 and the Laramie to the Cretaceous." Weed gives the following 

 table showing "the comparative sections found along the Rocky 

 Mountain front." 4 



1 Weed : loc. cit, p. 206. 



2 Quoted by Weed, loc. cit., pp. 206, 207. 



3 Weed : loc. cit., p. 210. 



4 Loc. cit., p. 211. 



