488 Scientific Intelligence. 



ian, and for many geologists most of what is considered Upper 

 Quader is of the same age as the Lower. In any case, if even 

 your splendid leaves, which you refer with doubt to the genus, 

 were true Credneria, their relation should be indicated as with 

 the Cenomaniau or with the original type, not with the derived 

 one in the Senonian. This, however, is of little importance, as 

 really the characters of these leaves are, in my view, far different 

 from those of Credneria, especially on account of the basilar posi- 

 tion of the lowest secondaries (or lateral primaries) and the 

 absence of the secondaries, or rather tertiaries, underneath. It is 

 also from the basilar point of attachment of the lateral primaries 

 that I can not recognize the identity of the two leaves of pi. xl, 

 fig. 8 and 9, with Platanus Meerii, whose leaves are moreover 

 entire. 



There is, however, a species of the Dakota group which shows 

 the closest relation (even identity?) to species of the Laramie. It 

 is Populus elliptica Newby., which can scarcely be separated by 

 distinct characters from P. cuneata of the same author. This 

 last species is therefore evidently of Cenomaniau type, the first 

 being the ancestor of Populus arctica, P. Pichardsoni, P. Zad- 

 dachi, P. speciosa, P. amblyrhyncha, P. Daphnoides, P. Oxy- 

 rhyncha, etc. The type is not seen with the Cretaceous of 

 Greenland; not even in the Patoot Senonian. But it is repro- 

 duced, and frequently so, in the Tertiary of Greenland, as you 

 well know. This with a number of other affinities tend to show, 

 in my opinion at least, that if there has been a migration of the 

 plants between America and Greenland at the Cenomaniail period, 

 the migratory movement has been northward, not southward. 

 But this question is out of place here. 



I received last Saturday the No. 37 Bulletin of the Survey with 

 the figures and descriptions of your Types of the Laramie. This 

 small volume is very handy and for study of paleobotany more 

 valuable still than the synopsis. Though I have sent an acknowl- 

 edgment of receipt to the Survey, I take the liberty to thank you 

 heartily for the production of a book which will be of great 

 assistance to paleobotanists of the present and especially for the 

 future American students of vegetable paleontology. What an 

 immense amount of material is still in reserve for those who fol- 

 low in your footsteps and collect specimens along the Yellow- 

 stone ! How is it that you did not find any Palms near Fort 

 Union, or along the Yellowstone ? 



Very sincerely and thankfully yours, Leo Lesqttereux. 



Professor Ward has sent the editors the following remarks on 

 Mr. Lesquereux's letter. 



To certain of the above criticisms, the force and legitimacy of 

 which I freely concede, the following reply may be made. 



I was not so fortunate myself as to find Palms in the Fort 

 Union beds, and the only ones coming from them that are known 

 to me are those determined by Dr. Newberry to which Professor 

 Lesquereux refers, and which represent only a single species, 

 Sabcd Campbellii Newby., which occurs so abundantly at Golden, 



