4 PROCEBDINGS OF THE NATIONAL MUSEUM vol. 82, art. 7 



according to some, lowermost Miocene. It is entirely distinct from 

 the earlier Oligocene Thompson Creek Beds, northwest of Three 

 Forks, and from the late Miocene or early Pliocene Madison Valley 

 Beds, on the east side of the river. When more is known about this 

 bed, it may deserve a special geographic name, but for the present it 

 will probably be sufficient to call it the John Day equivalent in the 

 lower Madison Valley. It may possibly prove to be synchronous 

 with some one of the scattered Oligocene patches of western Montana, 

 named by Douglass. 



REFERENCES 

 Douglass, Earl. 



1903. New vertebrates from the Montana Tertiary. Ann. Carnegie Mus., 

 vol. 2, p. 149. 

 Peterson, Olof August. 



1920. The American Diceratheres. Mem. Carnegie Mus., vol. 7, no. 6, 



pp. 414-417, pi. 57. 

 Troxell, Edward Leffinowell. 



1921. A study of Diceratherium and the Diceratheres. Amer. Journ. Sci., 



vol. 2, pp. 197-208. 

 Wood, Horace Elmer, 2d. 



1927. Some early Tertiary rhinoceroses and hyracodonts. Bull. Amer. Pal., 



vol. 13, no. 50, pp. 230-231. 

 1929. American Oligocene rhinoceroses — a postscript. Journ. Mamm., vol. 



10, no. 1, p. 73. 



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