Geology and Mineralogy. 487 



country, less known, perhaps, than any other country in Central 

 America. Abundance of vertebrate fossils, and relics of past 

 human races as well as plain though fast vanishing marks of the 

 early explorers of this country, fill these valleys from the Ulna 

 river to Truxillo. — Communicated to this Journal by the author. 



2. Professor L. F. Ward's Synop>sis of the Flora of the Lara- 

 mie group.— The following notes on Professor Ward's valuable 

 work are from a letter of August 9, 1887, to the author from Mr. 

 L. Lesquereux, received from the former by the editors. 



I am delighted with your excellent exposition, and thank you 

 heartily for the pleasure and instruction I have received from it. 

 Of course I do not agree with you in all your views, nor even 

 with all your assertions ; though that proves nothing against you. 

 I will only mark a few of the points on which I do not fully 

 agree with you. 



Considering the climatic circumstances, as indicated by the lo- 

 cal presence of some species of plants, you say, p. 438, that the 

 Palms of the lower districts of the Laramie indicate a difference 

 of climate greater than can be accounted for by the small differ- 

 ence of latitude. From Dr. Newberry's " Later Extinct Floras " 

 and from Dr. F. Y. Hayden's remarks, it appears' that the largest 

 specimens of fossil Palms (Sabal Campbellix), have been found in 

 the Fort Union Group; near the mouth of the Yellowstone, I 

 suppose. From the Raton Mountains, where plants of the same 

 kind are found in abundance, there is a difference of 22° of 

 latitude; and in that distance there is no marked difference in the 

 characters of the vegetation of the Lai'amie group, not even in 

 the absence of Ficus or of Cinnamomum at certain localities, and 

 therefore only a mere local difference. Ciwiamomum affine Lx., 

 a close relative of G. polymorphum, is not rare in the higher 

 strata of the Laramie, where you place the locality of Carbon. 

 Your exposition of the flora of the Iron Bluff, so remarkably 

 varied and different in each of the successive strata, is the best 

 possible indication of the extraordinary variety of the groups of 

 floras of the Laramie, though separated they may be at the same 

 localities by their intermediate strata. The same difference is re- 

 marked at Golden where, apparently at nearly the same horizon 

 and at little local distance, one of the strata bearing vegetable 

 remains has, in abundance, leaves of Platanus, Ficus Goldiana, 

 and Ficus spectabilis, while the other has mostly leaves of some 

 species of Populus and none at all of the species of the first exam- 

 ined bed. This, it seems, shows the impossibility of considering < 

 the difference in the vegetation of the Laramie at different locali- 

 ties as influenced by mere climatic circumstances. 



In the arrangement of your table of distribution which has 

 been prepared with the greatest care and has certainly demanded 

 long and careful research, I have to remark only on the admission 

 of the Credneria beds of the Upper Quader into the Senonian. 

 They are placed by Hosius at the very base of the Senonian, from 

 which he has a few leaves of Credneria. But the type of these 

 leaves is older; it pertains to the lower Quader or the Cenoman- 



