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Scientific Intelligence. 



In regard to the geographical, topographical, and physical features of 

 this country, its native tribes, its botany, zoology, &c, much interesting 

 information was long since laid before the public by the Reports of Lewis 

 and Clark's and Long's expeditions, by Mr. Catlin, the Prince of New- 

 Wied, Mr. Nuttall and others. More recently, much information of a 

 similar nature has been added by the report of the Pacific Railroad Sur- 

 vey. All these enterprising travellers mention the occurrence of sand- 

 stones, clays, lignite, &c, but without giving us much information in re- 

 gard to the age of these formations, the extent of country occupied by 

 them, or the character of their organic remains. 



In 1849, Dr. John Evans traced a great Lignite formation from below 

 Fort Clark, along the Missouri, to a point twenty miles below the mouth 

 of the Yellow-Stone; and in 1850 Mr. Thaddeus A. Culbertson, who 

 visited this country under the patronage of the Smithsonian Institution, 

 saw this formation at two or three points above Fort Union. In a map 

 accompanying a highly interesting memoir on the geology of the Hud- 

 son's Bay Territories, published recently by Mr. A. K. Isbister, in the 

 Journal of the Geological Society of London, a large area about the 

 sources of the Missouri, is colored as Tertiary, but so as to convey an in- 

 correct idea of the extent of country occupied by it. About the same 

 time, Mr. Jules Marcou published in the Bulletin of the Geological So- 

 ciety of France, a memoir on the Geology of the United States and the 

 British Provinces, accompanied by a map, on which he colors nearly all 

 the country about the head waters of the Missouri as New Red Sand- 

 stone, surmounted along the west shore of that stream by Cretaceous 

 outliers. Between this and the Black Hills he brings up to Cannon-ball 

 River, from the White River basin, a continuous belt of Tertiary. West 

 of this he places a belt of Jurassic, and along the supposed position of 

 the Black Hills he runs a stripe of eruptive and metamorphic rocks, 

 flanked on the east and west by Carboniferous formations. On the west 

 side of the Black Hills he colors another extensive district of Jurassic. 

 In all this Mr. Marcou is certainly mistaken, excepting in regard to the 

 eruptive and metamorphic rocks of the Black Hills ; there may also be 

 Carboniferous formations there, but they have not yet been recognized as 

 far north. by two or three hundred miles, as laid down by him. 



Leaving for a future occasion all local and other details, we now pro- 

 pose to give a brief general sketch of the extent and boundaries, as far 

 as we can, of that portion of the great Tertiary lignite formation from 

 which our fossils were collected, with a few remarks upon its probable 

 age, and relations to the White River basin, as well as to the Cretaceous 

 formations upon which it reposes. 



Ascending the Missouri from Fort Pierre, we find on reaching a point 

 five miles below Heart River, about the 47th parallel north, that the Cre- 

 taceous formations which are so conspicuous for many hundred miles 

 along the river below, pass by a gentle north or north-west dip beneath 

 the water level, to be succeeded on both sides of the river by tertiary. 

 Although this is the first point where the tertiary beds come down to the 

 water level, they are known to occupy the higher country back from the 

 river, on the west side, as far south as the vicinity of Sawacanna or Mo- 

 reau river, and still farther west they go as far south as some of the north- 



