1878. | United States Survey of the Territories. OF 
Mr. Orestes St. John, geologist of the Teton division, entering 
the field assigned to the Teton division of the survey at its south- 
western corner, the first five weeks were devoted to the examina- 
tion of the region lying in the great northern bend of the Snake 
river, and which includes an area of 1,700 to 2,000 square miles. 
The Blackfoot mountains are mainly composed of Carbonifer- 
ous strata, which mainly represent the earlier period, whose 
epochs are indicated by similar paleontological peculiarities 
which distinguish the Lower Carboniferous formations in the 
Mississippi basin, and which more extended research will doubt- 
less reveal in this distant region. But one of the most interesting 
discoveries in this connection was the presence of fish-remains, 
representing several forms identical with or closely allied to 
Keokuk species of the genera Cladodus, Petalodus, Antliodus, 
Flelodus. 
Dr. White, the paleontologist of the survey, has shown the 
identity of the lignitic series of strata east of the Rocky mount- 
ains in Colorado with the Fort Union group of the Upper Mis- 
souri river, and also its identity with the great Laramie group of 
the Green River basin and other portions of the region west of 
‘the Rocky mountains. He also finds the planes of demarkation 
between any of the Mesozoic and Cenozoic groups, from the 
Dakota to the Bridger inclusive, to be either very obscure or inde- 
finable; showing that whatever catastrophal or secular changes 
took place elsewhere during all that time, sedimentation was 
_ probably continuous in what is now that part of the continent 
from the earliest to the latest of the epochs just named. Other 
results and further details of the season’s work will appear in the 
following paragraphs. 
__ The general course of travel pursued by Dr. White during the 
= season was as follows, not including the numerous detours, 
_ meanderings and side trips which the work necessitated: Outfit- 
ting at Cheyenne, he journeyed southward, traversing in various 
directions a portion of the. great plains which lie immediately 
adjacent to the eastern base of the Rocky mountains in Colorado. 
The most easterly point thus reached was some sixty miles east 
of the base of the mountains and the most southerly point about 
_ twenty-five miles south of Denver. Returning to Denver to 
= renew his outfit, he crossed the Rocky mountains by way of 
Boulder pass through Middle park. After making certain com- 
VOL. XII.—NO, II. 8 
