30 TRANSACTIONS OF THE [nOT. 4, 



Mr. Lesquereus divides his Eocene-Tertiary into four groups, 

 as follows: Group 1: Raton Mts., " Placiere " [should be Placer 

 Mt.], Canon City, Golden, Marshall's, Erie, Sand Creek, Henry's 

 Fork, Fort Ellis, Spring Canon, Black Buttes, Alkali Station, 

 Point of Rocks, etc. 



Group 2: Evanston, Mt. Brosse, Troublesome Creek, Bridger's 

 Pass. 



Group 3: Carbon, Rock Creek, Washakie, Medicine Bow, Fort 

 Fetterman. 



Group 4: Barrell Springs, Green River Station, Sage Creek, 

 Florissant, Castello's Ranch, Elko.' 



The Fort Union beds he places above all the preceding and 

 calls them Miocene, for the same reason that I did, viz., because 

 he identified the flora with that called Miocene by Heer. 



Prof. Lester F. Ward, who is now in charge of the department 

 of fossil botany in theU. S. Geological Survey, and whose ability 

 and conscientiousness give special importance to all he writes, 

 has recently published " A Synopsis of the Flora of the Laramie 

 Group. '^ He accepts the erroneous view of Dr. Hayden, that 

 the Laramie and Fort Union groups are parts of one formation, 

 and this colors, and to a degree impairs, the value of his work. 

 He publishes figures of a large number of new species of fossil 

 plants collected by himself, mostly from the Yellowstone Valley. 

 To these he adds a few figures of true Laramie plants which 

 were obtained at Black Buttes, Point of Rocks, Goklen, etc.; 

 but his monograph as a whole is simply an important contribu- 

 tion to what was before known of the Fort Union flora. 



Among about one hundred species of fossil plants which he 

 figures from Montana, only one is found in the true Laramie; 

 this is Trapa microphylla, described by Mr. Lesquereux from 

 specimens obtained at Point of Rocks. Possibly the species may 

 not be the same, for Mr. Lesquereux's material was very meagre; 

 but probably it is the same and comes from the true Laramie 

 beneath the Fort Union beds. If it is the Laramie plant, and 

 found in the Fort Union strata, it will be the first species com- 

 mon to the Laramie and Fort Union floras that has come to my 

 knowledge in twenty years' study of these floras. Even should 

 one or several species of plants be found common to the Laramie 

 and Fort Union beds, this fact would not impair the truth of 

 the statement that I have made, that the Laramie and Fort 

 Union floras are radically distinct and should never be classed 

 together. 



Whether the Laramie is Cretaceous and the Fort Union 



' Recent investigations have shovrn that this classification requires 

 important modifications. 



