756 A. C. PEALE 
the Rocky Mountain region. Further, a comparison of the Fox 
Hills fauna from the Judith River Basin with those of other sections 
in the Rocky Mountains, particularly with those from Colorado 
where the most complete Fox Hills sections is found, shows that 
only 4 of the 18 species occurring in the Judith River section are 
not found elsewhere. These Fox Hills beds in the Judith River 
basin were named Claggett by Dr. Stanton, but apparently this 
is only another name for the Fox Hills formation as developed in 
the disturbed portions of the Judith basin. Our second conclusion, 
therefore, is that the Fox Hills formation, with its characteristic 
fauna and flora, immediately and unconformably underlies the 
Judith River beds and that it rests conformably upon exposures of 
characteristic Pierre shales throughout the Judith basin. 
It has further been shown that the Judith River beds occupy 
the identical stratigraphical position of the Lance formation. 
Both rest unconformably upon Fox Hills sandstones. Possibly 
we have in the Judith River beds the equivalent of only the lowest 
portions of the Lance formation. It has also been shown that out 
of 33 species of vertebrates occurring in the Judith River beds, 
23 are common to both the Judith River and the Lance formations. 
The invertebrates of both are mainly fresh-water forms which 
closely resemble each other in the two formations, and the plants 
of both, so far as they are known, suggest a Lance or Fort Union 
rather than the Belly River age. Undoubtedly there are areas on 
all sides of the Bearpaw Mountains in which, when we get beyond 
the area of disturbance due to the uplift, continuous sections will 
show below the Pierre shales, the Belly River series with char- 
acteristic floras, and above, the Judith River beds with floras 
referable to the Lance and Fort Union formations. There are indi- 
cations that the conditions are like those found on the Canadian 
side of the international boundary. We have no hesitation in 
stating the third conclusion, viz., that the Judith River formation 
is the representative if not the exact equivalent of the whole or of 
some, perhaps lower, portion of the Lance formation and that the 
latter name should be replaced on the ground of priority of use by 
the name Judith River formation. 
We have also seen that the Belly River series is always overlain 
by the Pierre shales not only in the Canadian sections but also 
