282 Annals of the Carnegie Museum. 



Aceratherium, 3 species. 



Elotherium ramosiim. 



Hyopotamus. 



Oreodon, 3 species. 



Leptomeryx sp. 



Hypertragulus. 



A lacertilian. 

 With the exception of the upper 100 feet of sand-beds and greenish 

 sandstones, the deposits at White Butte do not seem to correspond 

 very closely with Cope's description, neither does the list of the verte- 

 brates which I obtained exactly agree with his, though five or six 

 genera are probably the same. Cope's collection, however, which is 

 now the property of the American Museum of Natural History, is 

 labelled "White Butte, Dakota." There is a White Butte in the 

 northern part of South Dakota, about 60 miles southeast of White 

 Butte, North Dakota. The latter is sometimes called " Chalk Butte." 

 Professor A. G. Leonard ^* has described an isolated remnant of 

 what he thinks may be Tertiary deposits on the top of Sentinel Butte. 

 He says that "similar beds occur on top of Slim Butte and Cave 

 Hills, not far south of the North Dakota boundary, and on account 

 of their fossils are considered by Todd as of Miocene age.'"" 



While making a collection of vertebrate fossils at White Butte, and 

 in the Little Bad Lands (not the Little Missouri Bad Lands), in 1905, 

 the present writer studied these deposits quite carefully, so that they 

 might be compared with deposits of the same or nearly the same age 

 to the southward in South Dakota, Nebraska, Colorado, etc., and to 

 the westward in Montana. The general appearance and topography 

 of these beds is given in another portion of the present paper. 



The western portion of White Butte is a long ridge dissected in two 

 or three places by streams which have their origin between the 

 eastern and western portions of the butte. Its northern portion is 

 perhaps 300 feet higher than the surrounding plain and is broken into 

 mounds, hogbacks, and broken flat-topped ridges, but, on account of 

 the upward slope of the land, the ridge becomes relatively lower and 

 lower until it dies out on the plain to the southward. The northern 

 and lower portions of the butte are composed of Fort Union deposits 



'* Third Biennial Report of the North Dakota Geological Survey, 1903 and 1904, 



pp. 172-173- 



•'■•See South Dakota Geological Survey, Bull. No. 2, p. 62. 



