180 Association of American Geologists. 



of one of the teeth by Prof. Owen, should be referred to a genus 

 of the aquatic mammaUa, and which is now named " Zygodon," 

 — specimens of the vertebras of which, from the tertiary deposits 

 of Alabama, he exhibited to the Association. 



Mr. Nicollet then made some highly interesting remarks upon 

 the geology of the region on the Upper Mississippi, and the cre- 

 taceous formation of the Upper Missouri. 



He referred to his arrival in this country for the purpose of making a 

 scientific tour, and with the view of contributing to the progressive increase 

 of knowledge in the physical geography of North America. After spend- 

 ing several months in Philadelphia, Baltimore and Washington, he pro- 

 ceeded through the southern states ; explored the south Allegany range, 

 the states of South Carolina, Georgia, Kentucky, Mississippi, Alabama, 

 Florida, Louisiana, Arkansas Territory, and Missouri ; ascended the 

 Red. River, Arkansas river, and to a great distance the Missouri river. 

 Having thus made himself well acquainted with the lower half of the 

 Mississippi, he undertook the full exploration of that celebrated stream, 

 from its mouth to its very sources ; the latter of which he succesfully 

 reached near the close of the month of August, 1836. During five years 

 of unremitted exertions, he took occasion to make numerous observations 

 calculated to lay the foundation of the astronomical and physical geogra- 

 phy of a large extent of country, and more especially of the great and in- 

 teresting region between the Falls of St. Anthony and the sources of the 

 Mississippi. With these labors was connected the study of the customs, 

 habits, manners and languages of the several Indian nations, that occupy 

 this vast region of country. 



Mr. N. acknowledged, in feeling terms, the generous hospitality, on the 

 part of our citizens generally, of the agents of the American Fur Com- 

 pany, the civil and military officers, as well as the kind protection of the 

 government, extended to him on all occasions, so as gready to facilitate 

 his operations and second the accomplishment of his designs. At the 

 expiration of this long and arduous journey, Mr. N., broken in health, 

 and his means exhausted, returned to Baltimore, where he soon received 

 a flattering invitation from the war department and topographical bureau 

 to repair to Washington. The result of his travels having been made 

 known to these departments and appreciated by them, he was intrusted 

 with the command of a new expedition, to enable him to complete to the 

 greatest advantage of the country, the scheme which he had himself pro- 

 jected in his first visit to the far west ; namely, the construction of a map 

 of the region explored by him. This map having been recently submit- 

 ted to Congress, the senate of the United States has, unanimously, ordered 

 its publication under the direction of the topographical bureau. It is to 

 be accompanied by a report embracing an account of the physical geog- 



