J. S. NEWBERRY — THE LARAMIE GROUP. 529 



We cannot clearly recognize the American divisions ; but if the top of our beds repre- 

 sents the Fort Union, the Fort Pierre beds are six hundred feet below. I suppose, 

 then, that we would have to regard the intermediate shales and sandstones as Laramie, 

 though there is little to show why they should be separated from the Fort Union 

 group above. 



Professor Lester F. Ward : I take it that the discussion here to-day should avoid, 

 so far as possible, repetition of the statements that have already been published. Like 

 Dr. Newberry, I have in my hands a large amount of material both from the 

 typical Laramie group and from the Fort Union group, which has not been published. 

 A few years ago, as you all probably know, I did publish a paper on the Laramie 

 group, to which I prefixed a prefatory discussion in regard to the probable age of 

 that group. In that discussion I admitted that there was the same lack of identity 

 between the Fort Union fossil plants and those of the lower Laramie which Dr. New- 

 berry has pointed out. In further investigations of this material (for at that time I 

 had only studied a small portion of it, except in a very general way) I have not had 

 any occasion to alter my opinion in that respect, and I am to-day prepared to say 

 what I said then and what Dr. Newberry has said this morning, viz., that so far as 

 the floras of the Fort Union group and of that which was originally called the Lara- 

 mie beds of Colorado, Wyoming, and New Mexico are concerned, they are not identi- 

 cal — the^y are very different. 



I hazarded a possible explanation in case the geologists and animal paleontologists 

 eventually establish the synchrony of those beds, viz., that possibly the latitude taken 

 in connection with a different topography such as may have existed in the two regions 

 might account for the great difference in the floras. But I alsc expressed the opinion 

 that in all probability there would eventually be found a difference of age — how great 

 it would be premature for me to say. The great difference is not so much in the species 

 as in the general facies of the two floras. There are eight or ten identical species* in 

 the Laramie and Fort Union, but these weigh very little in comparison with the more 

 important fact that in the lower Laramie — the original Laramie formation — there is 

 a large predominance of such genera as Ficus, and also many palms, which, to the 

 mind of a paleobotanist naturally and probably correctly suggests a warmer climate. 



Whatever may be true in regard to the difference of age — and it seems to me that the 

 two must go together — I am quite satisfied that a warmer climate prevailed during the 

 period of the deposition of the Wyoming and Colorado beds than that which prevailed 

 during the deposition of the Fort Union beds. Among the leading genera of the upper 

 beds are Populus and Platanus. Some of these forms are, I admit, very irregular and 

 peculiar, but they are not found in any such abundance in the lower beds. They are 

 more northern forms — forms which now, at least, grow in the colder climates, and 

 very few species of Ficus, very few genera of palms, are found, so far as my own col- 

 lection is concerned, in the Fort Union beds. Moreover, as Dr. Newberry has stated, 



*The species common to the Laramie of Colorado and Wyoming and the Fort Union group, as 

 shown in the table of distribution given in my Synopsis of the Flora of the Laramie Group (Sixth 

 Annual Report U. S. Geol. Survey, 1885, pp. 443-514), are as follows : 



Sequoia langsdorfli, 



Sabal eampbellii, 



Quercus olafseni, 



Juglans rhamnoides, 



Juglans rugosa, 



Ficus tilicefolia, 



Magnolia hilgardiana, 



Trapa microphylla. 

 These are exclusive of several species thus far only found in the Laramie of British Columbia 

 and one of the American areas, as also of a number of more or less doubtful cases. 



