OTHEK TERTIARY INSECT LOCALITIES. ,37 



his passage down the river on horseback in 1S65, and his brief and cursor\- 

 account of the geological structure of the region is, I believe, the first ami 

 only one until the parties of the Hayden Survey entered the region ten or 

 more years later. Brief rej)orts of the geological and topographical character 

 of the country were made by Drs. C A. White and F. M. Endlich, and 

 Messrs. G. B Chittenden and G. R. Bechler. None of these, however, 

 obtained any insects, excepting Dr. White, who in a single locality found a 

 few poor specimens. On a visit to the place in the summer of 1889, how- 

 ever, I was able to rediscover the beds in which they were found by Mr. 

 Denton east of the Colorado-Utah line, and to greatly extend the stations at 

 which they could be found. In the two localities on the lower White River 

 where Denton found fossil insects, "Chagrin Valley" and "Fossil Canon," 

 as he called them, the general topographical features were the same, bluffs 

 or buttes of a thousand or more feet in thickness being composed of evenly 

 bedded stratified deposits. "Chagrin Valley " must be identified with the 

 valley of Douglas Creek, though it was not here but five or six miles lower 

 down the White River that Denton really obtained his fossils, at a point 

 where, to one traveling westward, Green River beds first appear in mass and 

 are readily accessible, probably in the immediate vicinity of Canon Butte, 

 where the old Indian trail on the south side of the river cuts off a siiarp bend- 

 and passes directly over many favorable outcrops. It was in fact at pre- 

 cisely this })lace that I obtained from the rocks collections agreeing most 

 closely in general appearance and character with those secured by Denton 

 This locality is in Colorado a few miles east of the Utah boundary. His 

 other locality is represented by him to be fifty or sixty miles farther down 

 the river, but still at some distance from its mouth. The distance is no 

 doubt exaggerated, and the locality on the north side of the river, certainly 

 in Utah, not improbably near the mouth of Red Bluff Wash. I made no 

 •search for this place. 



It may in brief be said that the Green River beds in the bluffs on each 

 side of the White River Canon near the boundary line between Utah and 

 Colorado, but especiall}^ on the northern side, are filled for over a thousand 

 feet with insect remains; the highest and the lowest beds respectively 

 yielded me the best results, but hardly a level could be found where patient 

 search did not reveal some relics, though perhaps of no value; the more 

 prolific beds were oftentimes simply crammed with remains, frequently in 



