STRATIGRAPHIC POSITION OF JUDITH RIVER FORMATION 531 
conclusions, made the statement that the Judith River beds lie 
immediately below the Fort Union (as then known), and have their 
equivalent in Colorado, occupying there the same position as in 
Montana. He also stated that he believed them to be of Creta- 
ceous age, and thought that they formed either the upper part of 
the Fox Hills, or a group to be called No. 6, the Fox Hills being 
known as No. 5. 
This opinion as to the Cretaceous age of the beds was based 
upon the study of the vertebrates by Professor E. D. Cope, a posi- 
tion which has been taken by all vertebrate paleontologists, both 
in the United States and in Canada. From this opinion the writer, 
in the light of what is known today, which will be briefly detailed 
below, dissents, and wishes to express here the conviction that the 
Judith River beds are of Eocene age. He, however, holds to his 
previous view that they do lie between the Fox Hills and the Fort 
Union formations as then known and described. ‘This is why they 
were so generally referred to the Laramie. This is the position 
that has been assigned them by everyone who has studied them 
from the time they were first noted by Hayden in 1853-55, and 
named by him in 1871, down to the time of the investigations by 
Hatcher, who was the first (in 1902)’ to assign them to a position 
in the Montana Cretaceous lower than that of the Fox Hills. In 
1896, however, Hatcher had considered the Judith River beds as 
representing the lower 400 feet of strata at the base of the Ceratops 
beds of Converse County, Wyo., and just above the Fox Hills 
sandstone. This position above the Fox Hills coincides with that 
assigned them by Hayden, Meek, Cope, and Osborne, and by the 
writer, as just stated. The position indicated for the beds by 
Hatcher, in 1902,” is that assigned them by Stanton and Hatcher 
in 1905, and their views are fully elaborated in their bulletin’ pub- 
lished by the U.S. Geological Survey. 
The historical aspect of this question has been so thoroughly and 
most admirably stated by Stanton and Hatcher in the bulletin just 
cited, and it is only necessary to recapitulate enough to show that 
the statement made above is correct. 
t Science, XVI, 831, 2. 
2 I aytal 9) DWAIN) zeae 3 Bull. U.S. Geol. Surv., No. 257, 1905. 
