No. 3. — Preliminary Account of the Fossil Mammals from the 

 White JRiver and Loup Fork Formations, contained in the Museum 

 of Comparative Zoology. Part II. The Carnivora and Artiodac- 

 tyla hy W. B. Scott. The Perissodactyla by Henry Fairfield 



OSBORN. 



This paper, the second upon the Fossil Mammals of the Museum of 

 Comparative Zoology, is a continuation of the one published by the 

 writers^ in August, 1887, upon the White Eiver Mammalia, and in- 

 eludes a number of additions to and corrections of the results there 

 described. It is, however, especially devoted to a consideratiou of the 

 upper Miocene or Loup Fork mammals collected in Nebraska by Messrs. 

 Garman and Clifford, and in Kansas by Mr. Sternberg. The specimens 

 from these different localities exhibit a considerable range of specific 

 variation. 



The Loup Fork species here described have for the most part been 

 long established, but these collections add much to our knowledge, and 

 enable us to determine very fully the structure of forms which have 

 been known hitherto only from fragments. Of such new observations 

 we may mention: (1) the determination of the foot structure of Meryco- 

 choerus; (2) oi Elastomer yx ; (3) the restoration o^ Cosoryx ; (4) discovery 

 of the mandible of jElurodon hycenoides; (5) the discovery of an exceed- 

 ingly large feline animal ; (6) observations upon the molars of the equine 

 series; (7) the manus and pes of Aceratherium; (8) the skeletal char- 

 acters and restoration of Aphelops fossiger ; (9) the homologies of the 

 elements of the molar teeth in the rhinoceroses; (10) the brain char- 

 acters of Aphelops and Mesohippus ; (11) the discovery of a Loup Fork 

 species of Chalicotherium. 



We have again to express our thanks to Dr. F. C Hill, Curator of 

 the Geological Museum at Princeton, for his skilful excavation and 

 mending of the specimens, and to Mr. R. Weber for the very accurate 

 series of drawings which accompany this paper. 



Geological Museum, Princeton, N. J., July 8, 1890. 



1 The authors, as initiated in their Memoir upon the Uinta Mammalia, have 

 divided the subjects for their present and future joint papers. 



VOL. XX.— NO. 3. 6 



