HAWORTH: division of the KANSAS COAL MEASURES. 293 



deprived of variations. The great familiarity Mr. Bennett has pos- 

 sessed for years with the invertebrate fauna of the Coal Measures of 

 Iowa, Missouri, Kansas and the Indian Territory made it an easy 

 matter for him to point out a horizon at which there was a consider- 

 able abruptness of faunal variation which seems to be sufficient to 

 warrant a division of the Coal Measures. 



According to paleontologic evidence obtained by Mr. Bennett, 

 there is quite a faunal change at the top of the Pleasanton shales. 

 One species CJionetes inesoloba, which is very abundant and wide 

 spread below this line cannot be found above it anywhere in the 

 state. Not only this, but different species first appear in the Erie 

 limestone, thus making a change of considerable importance in the 

 fauna at this line. 



This unusual faunal change is accompanied by as great physical 

 changes as can be found at any line. It has the great bed of the 

 Pleasanton shales below it and the Erie or Triple limestone group 

 above it, each of which has been traced entirely across the state from 

 Kansas City to the south line. In addition to this the same two 

 formations reach, according to Broadhead, from Kansas City north- 

 wards to the border of Iowa, the lower member of the limestone 

 series being known as the Bethany Falls limestone, number 78 of 

 Broadhead's general section. They also extend in undiminished 

 thickness to the west under the surface as far as can be determined 

 by the various deep wells, with no reason of doubting their uninter- 

 rupted extension for a hundred miles or more beyond. 



To sum the matter up in a few words, it is proposed to divide the 

 Coal Measures of Kansas into two divisions, to be designated by the 

 terms Lower (Joal Measures and Upper Coal Measures, the division 

 line to be at the top of the Pleasanton shales, which is at the bottom 

 of the Erie or Triple limestone, the basis of division to be principally 

 paleontologic, but also partially dependent upon the great physical 

 change which marks the line between the two extensive and char- 

 acteristic formations, the Pleasanton shales and the Erie limestone. 



This division does not correspond with either one used by Broad- 

 head for the Missouri Coal Measures. His division between the 

 Middle and Upper is a sandstone situated a little below the Bethany 

 Falls limestone and therefore a little below the line here proposed. 

 Why Broadhead should have chosen sandstone to mark his division 

 line cannot be understood, for, at least in Kansas, all the Coal Meas- 

 ure sandstone is so limited in its extent that it can be used for no 

 lines of demarkation whatever, excepting for the most local divisions. 

 In his excellent Report on the coal deposits of Iowa Dr. Keyes* 



*Ia. Geol. Surv., Vol. il. 1894. 



