118 PROCEEDINGS OF THE ACADEMY OF 



la 1843, Mr. Edward Harris, who accompanied the distinguished Ornitholo- 

 gist Audubon to the mouth of Yellowstone River, brought back specimens from 

 various localities along the Missouri River, some of which verified the state- 

 ments of former explorers, while others gave evidence of the existence of a fresh- 

 water formation near Fort Union. 



At various times after this, specimens of mammalian remains were brought 

 iu by gentlemen connected with the American Fur Company, indicating the ex- 

 istence of an interesting tertiary deposit on White River; the first account of 

 which was published by Dr. H. A. Prout, of St. Louis, in the American Journal 

 of Science, 1847. 



In 1849, Dr. John Evans, one of Dr. Owen's assistants in the geological survey 

 of the Chippeway Land District, was sent by that gentleman on an expedition 

 to the Mau,vaises Terres of White River, and brought back a fine collection of 

 Mammaliaa and Chelonian remains, which w^re investigated by Prof. Leidy, of 

 Philadelphia. He also collected at the Great Bend, Sage Creek, and Fox Hills, 

 many interesting Cretaceous fossils, which were investigated by Dr. D. D. Owen, 

 and published in his final report in 1852. Dr. Evans' observations, embracing a 

 section of the Bad Lands, together with a deseription of their physical features, 

 were also published in this report. 



In the following year Mr. Thaddeus A. Culbertson visited the Upper Missouri 

 country under the auspices of the Smithsonian Institution, during which expe- 

 dition he collected some interesting vertebrate remains from the White River 

 formations. He also ascended the Missouri on the Fur Company's boat to a 

 point above Fort Union, noting the character of the face of the country, and the 

 occurrence of lignite beds at various localities. 



In the spring of 1853, Dr. Evans again visited this country incidentally, while 

 on his way to Oregon Territory, in the geological survey of which he was en- 

 gaged, uuder the patronage of the general government. During this expedition 

 he made another extensive collection of vertebrate remains, and some fresh- 

 water mollusca at the Bad Lands of White River, as well as some interesting 

 Cretaceous fossils from Sage Creek. The mammalian remains of this expedition 

 were studied by Prof. Leidy, and the other fossils by Dr. Evans and Dr. Shu- 

 mard, and published in the Proceedings of the Acad. Nat. Sc. at Philadelphia, 

 and the Acad. Sciences of St. Louis. 



At the same time (1853) the writers of this paper were employed by Prof. 

 James Hall, of Albany, N. Y., to visit the Bad Lands of White River, for the 

 purpose of making a collection of the Tertiary and Cretaceous fossils of that 

 region. This expedil^ion brought back an extensive and interesting collection 

 of vertebrate remains from the Bad Lands, and of Cretaceous fossils from Sage 

 Creek, as well as from the Great Bend and other localities along the Missouri 

 below Fort Pierre. The first were investigated by Prof. Leidy, and published in 

 the Proceedings of the Acad. Nat. Sc. at Philadelphia; and the latter by Prof. 

 Hall and one of the writers,* and published in the Transactions Acad. Arts and 

 Sciences, Boston. 



In this latter paper a brief vertical section of the rocks seen during the expe- 

 dition, and a complete list of all the mollusca then known from the Cretaceous 

 and Tertiary rocks of that country, were given. The fact that the fossils charac- 

 terizing the Cretaceous formations of Texas and New Mexico belong to different 

 types from those occurring in the northwest, was also in this paper made 

 known for the first time, in the following words : "Among all the collections 

 made in Texas by Dr. Roemer and others, and of all those brought by the 

 , Boundary Survey Expedition, and other surveying and exploring parties, which 

 we have seen, there is but a single species which we regard as doubtfully identi- 

 cal with one from Nebraska. This is Inoceranms Barabini, Morton, (I. Crispii, 

 Mantell (?) )." 



A summary of the leading results of this expedition, throwing light upon 



*Mr. Meek. 



[May, 



