PEEFACE. XXvii 



Mammalia and Reptilia of tlie Loup Fork formation of Northern Kansas 

 was made, Mr. Hill discovering several new species of Mastodon, rhinoce- 

 roses, tortoises, &c. 



The Tertiary formations explored in 1878 were the John Day, Loup 

 Fork, and Equus beds, of Oregon. These were examined by Mr. C. H. 

 Sternberg, who received important aid from his brother, Dr. George M. 

 Sternberg, U. S. A. The John Day formation was chiefly examined on the 

 John Day's River, and the Loup Fork beds at various points in the same 

 region. These yielded about fifty species, many of them ]-epresented by 

 specimens in an admirable state of preservation. The Equus beds were 

 examined both in Washington and Oregon; in the former near to Fort 

 Walla Walla, and in the latter in the desert east of the Sierra Nevada. 

 The basin of an ancient lake, originally discovered by Governor Whit- 

 aker, of Oregon, was found to be strewn with the bones of llamas, horses, 

 elephants, sloths, and smaller mammals, with birds; and all were collected 

 by Ml-. Sternberg and safely forwarded to Philadelphia. I examined this 

 locality myself in 1879, and obtained further remains of extinct and recent 

 species of mammalia found mingled with numerous worked flints. 



In 1879 Mr. J. L. Wortman took charge of m}^ party exploring in 

 Oregon, and made extensive and valuable collections of the fossils of the 

 John Day and Loup Fork beds of the eastern part of that State. In 1880 

 Mr. Wortman explored the deposits of the Idaho Pliocene lake of the 

 Snake .River Valley, and made a valuable collection.* The same year he 

 examined the Eocene beds of the Wind River Basin previously discovered 

 by Dr. Hayden, and sent east forty-five species of vertebrata, of which 

 twenty-four were new to science. In the following year Mr. Wortman 

 pushed his explorations northwards, and discovered that the basin through 

 which the lower part of the Big Horn River flows is filled with deposits of 

 Wasatch Eocene age. These he examined for vertebrate . remains, and 

 succeeded in obtaining sixty-five species, of which twenty- seven were 

 previouslv unknown. Most important additions to our knowledge of the 

 structure of various types were made, owing to the i-emarkably perfect 

 condition of some of the specimens. 



•Proceedings Academy, Philadelphia, 1883, p. 153. 



