: 
ind river chain. Passing the first range of mountains in the 
Laramie plains, we find that the Big Laramie river cuts through 
Cretaceous beds, Nos. 2 and 3, continuing our course westward 
to Little Laramie, a branch of the Big Laramie, and No, 3 be- 
_and in a horizontal position across the Laramie range prior to 
its elevation. 
_ + cannot discuss this matter in detail in this article, but the 
evidence is clear to me now, that all the lignite Tertiary beds of 
the west are but fragments of one great basin, interrupted here 
and there by the upheaval of mountain chains or concealed by 
the deposition of newer formations. 
the evidence that I can secure seems to indicate that 
there are no valuable beds of lignite west of the Mississippi, in 
formations older than the Tertiary. 
Postscript, 
After my article on the Lignites of the West was in type, 
Professor Lesquereux sent me the following very valuable notes, 
as the result of his preliminary examination of the fossi 
Species from Rock creek, Laramie Plains. 
1. Populus attenuata Al. Braun. The identity of these leaves with 
the European species is undoubted. 2 
2. Populus levigata, sp. nov., related to P. balsamoides Gipp., a 
PPecies, which, like the former, is abundant in the Miocene of 
urope. . 
3. Pieke: subrotunda, sp. nov. Type of neuration of P. melan- 
aria Heer, and form of leaves of P. mutabilis Heer, both species 
also common in the Miocene of Lk gy —— 
cus acrodon, sp. nov., 2 fine oval leaf resembling a chestnut 
now time 
. leaf, related to Quercus 
prinoides V of ou : 
ercus Haydeni, sp. nov., lyrate leaf with lobes strongly den- 
tate, without near relation to any species, either of the Tertiary 
or of our time. 
