16G 



BULLETIN : MUSEUM OF COMPAllATIVE ZOOLOGY. 



as " of flat-iron shape, with tlie broad end to the south resting upon the 

 Kansas-Nebraska line. The northern limit is probably in the vicinity 

 of Eoca, Lancaster County. On the east the boundary has only been 

 approximated, . . . but it is supposed that it extends from Roca south 

 and east into Johnston 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 is traced with considerable accuracy." An under- 

 standing of the stratigraphic relations of the Upper Palaeozoic rocks in 



GEOLOGICAL MAP 



o r 

 SOUTH-EASTERN 



RASKA 



COAL MiAsunca. 



PERMIAN 

 /E^ VAKOTA CROue 



Fig. L 

 A Geological Map of Southeastern Nebraska (after Knight). 



Nebraska will be facilitated by an inspection of the accompanying 

 sketch-map and section, taken from Professor Knight's article, and of 

 the following table of formations. The stratigraphy of the Kansas 

 Coal Measures is described in the report of the University Geological 

 Survey of Kansas, particularly in Volume III. by E. Haworth. 



Nearly all of the fish-remains described in the present paper are 

 from the Atchison shales, the principal localities being in Cass, Gage, 

 Lancaster, Nemaha, and Sarpy counties. According to Dr. Barbour, 

 the exposures at Cedar Creek, Louisville, South Bend, and Table Rock 



