36o IV. C. KNIGHT 



history bearing on these rocks, and added much valuable infor- 

 mation to the literature by a careful examination of the many 

 exposures. His classification must stand as a basis for cor- 

 relating the Permian rocks of the central western United States. 

 The Nebraska Permian is the northern extension of Kansas 

 beds, and agrees with them in all of the essential characters. 

 The area is of a flatiron shape, with the broad end to the south 

 resting upon the Kansas-Nebraska line. The northern limit is 

 probably in the vicinity of Roca, Lancaster county. On the east 

 the boundary has only been approximated, since the highlands 

 separating the valley of the Nemaha from the valley of the Big 

 Blue River, are so deeply buried with loess that there are few, 

 if any, rock exposures. Typical Permian rocks were found near 

 the eastern line of Gage county, and Coal Measures near Pawnee 

 City, Pawnee county. From these data it is supposed that the 

 eastern boundary of the Permian extends from Roca south and 

 east into Johnson county, thence southward through the western 

 end of Pawnee county into Kansas. The western boundary, from 

 Roca to Beatrice, is also buried beneath a very thick bed of 

 loess ; but from Beatrice southward it was traced with consider- 

 able accuracy, since there were numerous outcrops of both Per- 

 mian and Dakota sandstone. Only a short distance west of 

 Beatrice the Dakota sandstone crosses the river and trends south 

 and east along the southwestern border of the valley of the Big 

 Blue River to a point known as "The Mounds," which is a high 

 bluff capped by Dakota sandstone on the west bank of the river 

 some two miles west of Holmesville. From this bluff, the highest 

 in this section of the country, the boundary trends south and west, 

 passing several miles west of Blue Springs, thence westward 

 along the north side of Indian Creek to a point about two miles 

 west of Odell, where it crosses the creek and turns eastward and 

 follows the south side of the valley of Indian Creek nearly to 

 the Big Blue River, where it bends southward and keeps a 

 southern course to the Kansas line. As bounded, this area, 

 comprising nearly five hundred square miles, is nearly confined 

 to Gage county, and, with the exception of that portion in 



