1869.] ^^ [Haydcn. 



Station, 80 miles west of Laramie. At Carbon where tliey are exposed to 

 view, impressions of fossil leaves occur in the greatest abundance. The 

 species are few and nearly all of them identical with those described by 

 Dr. Newbury, from^the miocene tertiary beds of the Upper Missouri. 

 Some strata consist almost entirely of leaves, in a fair state of preserva- 

 tion, as if they had not been subjected to a great deal of drifting prior to 

 deposition. Indeed, the trees themselves must have grown near the spot, 

 to shed their leaves in such great abundance, just as we find leaves 

 accumulated now in muddy bottoms. Dr. Newbury has identified from 

 this locality, Pcjndus Ouneata, Populus Nebrascensis, Platanus Haydeni and 

 an undescribed species of Cornus. The Wyoming Coal Company's shaft 

 sunk at this station to reach the coal, has descended nearly 60 feet through 

 a considerable thickness of bluish-black arenaceous clay, in rather thick 

 layers, iipon the surface of which are great quantities of Populus and 

 Platamis. Very nearly the same species are described throughout a great 

 thickness of these tertiary beds, and the evidence seems to be pretty clear 

 that the vegetation was nearly uniform throughout the period of the 

 deposition of the coal strata. 



The Cretaceous beds are again exposed in a sort of anticlinal valley, 

 about 10 miles east of the N. Platte crossing. But a few miles on either 

 side of the railroad tertiary beds are seen. 



At Rawling's Spiings, all the formations from the syenites to the cre- 

 taceous, are thrown up over a restricted area ; 2 miles farther west, the 

 tertiary beds again overlay. At Separation, 26 miles west of Benton Sta- 

 tion, a bed of excellent coal has been opened by the railroad company, in 

 the rocks over which Platantos Haydeni and Cornus acuminata, (N, ) with 

 other undetermined species of plants occur. This forms the eastern rim 

 of a basin which extends about 110 miles to the westward. 



Soon after leaving Separation, the strata becomes nearly horizontal, and 

 are of fresh water instead of estuary origin. Beyond Bitter Creek Station, 

 estuary beds reappear dipping east. At Washakie, Red Desert and Table 

 Rock occur thick beds made up of an aggregate of fresh water shells, of 

 the genera TJnio, Paludina, Limnea, Melania, &g., At Black Butes and 

 Point of Rocks, a great abundance of impressions of deciduous leaves are 

 found. At Black Bute Station, about 850 miles west of Omaha, I found 

 in the coal strata Sabal GamphelU, N, BJiamnus elegans, Cornus acuminata, 

 Qiiercus aceroides, Tilia antiqtoa, with some undescribed species. 



At Point of Rocks, an important coal station, about 14 miles farther 

 west, I found Platamis Haydeni, P. Nebrascensis, Cornus acuminata, and 

 Magnolia tenerafolia. In the vicinity of Elk mountain, along the overland 

 stage road, in beds which I regarded as belonging to the older terliary, 

 and holding a position near the junction of the tertiary and cretaceous, 

 and nearly or quite on a parallel with the lower tertiary beds near Den- 

 ver, Colorado, I found Plaiinus Haydeni, Qtiercus aceroides, Mag.nolia 

 tenerafolia,' with fragments of Cornus and Bhamnus. 



Near Green River the eastern rim of what appears to be another tertiary 

 basin commences, the beds having a gentle dip to the westward. Between 



