STRATIGRAPHIC POSITION OF JUDITH RIVER FORMATION 743 
opinion of the writer this prophecy of Leidy’s made in 1860 is today 
being verified. 
Professor E. D. Cope, with the assistance of C. H. Sternberg 
and John C. Isaacs, spent a part of the summer of 1876 in the explo- 
ration of the Judith River basin between Fort Benton and Armell’s 
Creek, 130 to 150 miles farther down the Missouri River,’ and 
secured a considerable number of dinosaurs, referable to several 
new genera and species, and fragmentary remains afterward 
determined to be Ceratopsia. Hatcher spent a couple of months 
of the summer of 1888 in the Judith River badlands with what he 
calls very indifferent success,? and in the summer of 1903, with 
T. W. Stanton, spent two more months ‘‘in the field study of the 
Judith River and associated formations of northern and central 
Montana and adjacent areas of Canada.’’ 
In the interval between 1855 and the present time (1912) 
explorations have been carried on over widely separated areas in 
the Rocky Mountain region of the United States, resulting in the 
discovery and development of many localities from which verte- 
brate remains (many in a fragmentary condition) have been col- 
lected, the beds in which they occurred being post-Laramie forma- 
tions. The most characteristic species appear to be those of genera 
belonging to the Ceratopsia, one of the first described species coming 
from the beds at Black Buttes, Wyo. 
Besides the localities in Converse County, Wyo., collected by 
Hatcher, Williston, Baur, and Case, and the Denver and Arapahoe 
areas of Colorado by Cannon, Cross, and Eldridge, and the Hell 
Creek region by Barnum Brown, many others in the Rocky Moun- 
tain region have yielded vertebrate remains, mostly, however, in a 
fragmentary condition. Thus Ceratopsia have been found near 
the North Platte River in Wyoming about 4o miles north of Fort 
Steele by Hatcher in 1888, and from near the same locality by 
Knowlton and Peale in 1910, here also by Hatcher, on the east side 
of the Big Horn Mountains 40 miles south of Buffalo, Wyo.; on the 
west side of the Big Horn River between Fort Custer and Custer Sta- 
t Bull. U.S. Geol. and Geog. Surv. Terr., III (1877), 565-97. 
2 Monograph U.S. Geol. Surv., XLIX (1907), 7. 
3 Bull, U.S. Geol. Surv., No. 257, 1905, p. 9. 
