jnowlton.J LOCALITIES IN BITTER CREEK VALLEY. 5 
There is do satisfactory exposure of the overlying strata near this 
3oal, but at a point about 3 miles to the southwest, near the old 
stage crossing of Cooper Creek, and certainly higher in position, the 
beds are very fossiliferous and contain a typical Fox Hills fauna of 
ibout twenty-five species. It is of course possible that there is a fault 
)r other disturbance between these two points, but no evidence of it 
ippeared, and the relations before mentioned are probably correct. 
Hie evidence afforded by the plants, while somewhat conflicting, tends 
;0 place this plant horizon well down in the series, or approximately 
;imilar to the plant horizon of Harpers, for at least two of the species 
freinitzia formosa and Brachyphyllum macrocarpum) are common to 
)oth localities. These are very characteristic species and can not 
veil be mistaken. Of the other species two (Trapa f microphylla and 
Dioxpyros f Jicoidea) are found at Black Buttes and at Point of Rocks, 
vhile the remainder of the forms previously named have a higher 
listribution. These latter, however, rest on single examples and are 
tot entitled to the weight that should be allowed the others, which are 
epresented by numerous specimens. For the present at least it seems 
•est to regard this flora as belonging to the Montana formation. 
The remaining coal and plant-bearing horizon that we visited on the 
>aramie Plains, now known as the " Button Creek mine," is similar 
i age to the coal of Carbon, and is regarded as Laramie. 
LOCALITIES IX BITTER CREEK VALLEY. 
The stratigraphy and paleontology of the Bitter Creek Valley and 
nmediate vicinity have been much studied and have given rise to 
rolonged discussion. The exposures are in most cases extensive, and 
nhe fossils, both plant and animal, are very abundant. 
Black Buttes Station is one of the most important of these localities, 
nd has been frequently visited by geologists. It is introduced into 
ic present discussion only on account of the geological and paleonto- 
l )gical bearing it has on certain other points in the Bitter Creek 
alley. 
The following brief account of the geology at Black Buttes is taken 
om the paper before referred to by Mr. T. W. Stanton and myself 
). 143) : 
The most prominent feature of the section of Black Buttes is the massive bed of 
ndstone, somewhat over 100 feet thick at the base of the exposure, forming steep 
lis and cliffs northeast of the railroad opposite the station, and passing beneath 
e surface by its dip of 9 or 10 degrees near the coal mine. The upper portion of it 
also exposed on the south side of Bitter Creek Valley, about a mile from the 
ation. 
All of the Laramie fossils, whether plants, invertebrates, or vertebrates, that have 
i therto been described or listed as coming from Black Buttes, were obtained from 
e overlying beds within about 100 feet of the top of this massive sandstone. The 
iginal specimen of Agaulhaumus sylvestris was found about 20 feet above it, and 
e plants that have been described catne from the same horizon and from several 
gher bands up to the bed overlying the principal coal, some 60 or 75 feet higher. 
ie invertebrates from tins locality have, about the same range. Most of the beds 
