328 [December, 



The species is named in honor of Dr. D.D. Owen, of New Harnnony, Indiana, 

 who has contributed this as well as numerous other objects to Palceontology. 



Dr. Owen made the following observations on the locality of the fossils 

 from the " Mauvaises Terres " of Missouri. 



The region of country where the remains of the fossil mammalia exhibited 

 were procured, is a part of the district known to the French Canadian voya^eura 

 of the Upper JVIissouri as the Mauvaises Terres or Bad Lands, which lie between 

 the Missouri river and the base of the Black Hills, and the waters of the Shagea 

 and Moreaux. It presents the appearance of the great bed of some ancient lake, 

 the base of which is some three hundred feet below the general level of the wide 

 expanse of prairie which rises in terraces towards the Rocky Mountains. 



This depressed valley of the Mauvaises Terres appears more a valley of exca- 

 vation than of subsidence, as is proved by the multitude of isolated pinnacles, 

 mounds, and curious outliers, which, having resisted the denuding forces, 

 stand in all imaginable fantastic shapes, memorials of the excavating forces that 

 have been at work. These rise to the height of from two to three hundred feet, and 

 form between them a complete labyrinth of intricate passages stretching as far as 

 the eye can reach, that soon bewilder the incautious explorer. 



These remarkable insulated peaks, like the sides of this great valley, are com- 

 posed of horizontal beds of indurated clays, marly strata, and thin beds of quartz 

 ore conglomerates, all probably belonging to the age of the Eocene tertiary, and 

 are the receptacles of those unique fossil remains, presenting a most extraordinary 

 assemblage of pachyderms, some of which seem to have combined the at present 

 anomalous character of ruminants, associated with a few carnivorous animals. 



The skulls, bones, and fossil fre'sh-water turtles are mostly found on mounds of 

 white, pale flesh-colored, and light grey and greenish marly and argillaceous 

 earths, the debris of denuded strata. The Palseotherium bed lies towards the 

 base of the section, from ten to twenty feet above the bottom of this great 

 valley. 



Further details concerning this curious country and its ancient fauna, together 

 with a section of the strata composing it, will be found in the forthcoming geo- 

 logical report of the North West. 



The Committee on Proceedings announced that Dr. Meigs' Memoir of 

 the late Dr. Morton was published, and was now ready for distribution. 



On, motion of Dr. McEuen it was 



RcRoIved, That the thanks of the Society be presented to M. Desmers, 

 Bishop of Vancouver, for his offer of the hospitalities of his Mission to 

 the members, and of his assistance in furthering the objects of the 

 Society, and that a Committee be appointed for the purpose of seconding 

 hi? proposal. 



Committee, Dr. McEucn, Dr. Horner, and Dr. Leidy. 



