252 KANSAS UNIVERS^^^• (,)UAR1'ERLY. 



The sole difference discoverable is the relative greater abundance in some 

 places among the upper rocks of iron, giving, when acted upon chemically, a more 

 buff or yellow color to the chalk and a deeper color to the " blue shales." There 

 IS a paleontological distinction between the upper and lower beds, as the writer 

 has already pointed out, (op. cit.), and if one needs characteristic terms for the 

 two horizons, the names Hesperonnis and Rudistes beds would be far preferable. 

 Nor is there any geological horizon of jasper, and I am surprised that the author 

 should have so intimated. As is well known, the Nebraska Tertiary beds lie 

 iincoiifo)-7nably upon the Niobrara, and the silicification of the uppermost part of 

 the chalk from the percolating waters could not possibly produce a geological 

 horizon. 



The resent writer was the first to call attention to the presence in Kansas of the 

 Ft. Pierre deposits. Since that time he has had the opportunity of studying the 

 same group of rocks in various other regions to the northwest. There is absolutely 

 no difference, yet discovered, either lithological or palseontological to distinguish 

 the outcrops in Wallace county from those of the typical beds in Dakota and else- 

 where. Professor Cragin proposes to call these beds in Kansas the "Lisbon 

 Shales," but he gives nothing whatever to distinguish them from the beds above 

 them. Why then should they have a distinct name? Nor does he give any 

 reasons for naming the Arickaree shales of the Fo.x Hills group in Cheyenne 

 county. One is hardly justified in naming geological horizons without attempting 

 to define them. There has already been too much of such aimless nomenclature. 

 The author seem to have been unaware of the publication of the paper by the un- 

 dersigned in the Trans, of the Kansas Academy. 



S. W. WiLLISTON. 



