INTRODUCTORY REMARKS. 



XXV 



General section of the Cretaeeovs rocks of tfebrasJca — Continued. 



Although the foregoing section has heen frequently published in papers 

 and reports issued at various dates since its first appearance, its introduction 

 here seems necessary, in order that the student, in using this report, may 

 have the means of understanding the relative positions of the beds from 

 which the fossils hereinafter described were collected, without having to 

 refer to other publications. The following remarks on each of these subdi- 

 visions, commencing with the oldest, will also explain more fully the nature 

 and geographical extension of each. 

 u— IV 



