574 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



Scapherpeton excisum Cope, 1. c, 1876, p. 357. 

 Scapherpeton favosum Cope, 1. c, 1876, p. 357. 

 Hemitrypus jordcmianus Cope, 1. c, 1876, p. 358. 



PISCES. 



ACTINOPTERI. 



Ginglyniodi. 



Lepidosteus occidentaUs Leidy; Lepidotus haydeni et Lepidotus occi- 

 dentalis Leidy, Proc. Acad. Phila., 1856, 73 ; Trans. Amer. Philos. Soc, 

 1860, p. 149. 



? Dipnoi. 



Arotus Meroglyphus Cope; Ceratodus Meroglyphus Cope, 1. c, 1876, p. 

 260. 



? Arotus eruciferus Cope; Ceratodus eriiciferus Co^pe, 1. c, 1876, j). 259. 



? Elasmobranchii. 



Myledaphus hipartitus Cope, 1. c, 1876, p. 260. » 



Hedronchus ster-nbergi Cope, 1. c, 1876, p. 259. 



Subsequent to the deposit of the Judith River beds, they, with the 

 underlying formations, were subjected to great disturbances, which ap- 

 peared in lines of elevation running generally east and west. The strata 

 rise to these axes at various angles, and are sometimes thrown up so as 

 to be vertical. The summits of the axes are thus frequently composed 

 of the shale of the Fort Pierre epoch, or of the rusty Fox Hills sand- 

 stone capping it, leaving the Judith Eiver beds in synclinal troughs 

 These are cut through by the Judith River and Dog and Birch Creeks, 

 where the stratification is well exhibited. Fig. 4 represents a butte of 

 No. 6, between bluffs of 1:^0. 4 on Dog Creek, three miles from its mouth. 

 Fig. 5 represents a bluff of No. 4, which descends beneath the border of 

 No. 6, at a locality on the west side of Birch Creek. At several locali- 

 ties near and below Cow Island, axes of elevation run nearly north 

 and south cross the Missouri Eiver, elevating theTaeds at high angles. 

 These disturbances were probably connected with the elevation of the 

 Bear Paw and Little Rocky Mountain Ranges on the north side of the 

 Missouri River, as has been remarked by Hayden.* 



From what has preceded, the general conclusion is reached, that the 

 series of beds from the lowest of the Fort Pierre epoch to the summit of 



* Iq the geological portion of Captain Ludlow's Report of an Exploration from Carroll 

 to the Yellowstone Park, by Messrs. Dana and Grinuell, p. 125 (1875), it is stated that 

 " a carefnl examination will, however, serve to convince the observer that all the beds 

 are really horizontal, and that the apparent bendings and twistiogs of the rocks 

 referred to by Dr. Hayden are due simply to the action of running water". My obser- 

 vations, prolonged over two months, enable me to fully confirm the statements of Dr. 

 Hayden. 



