258 University Geological Survey of Kansas. 



pedition to western Kansas during the summer of 1898 ob- 

 tained some valuable material from the Niobrara and Fort 

 Pierre formations, among which several new types have ap- 

 peared. Before entering into the work in detail, I wish to ex- 

 press my indebtedness to Dr. S. W. Williston for advice in the 

 preparation and revision of the work, and also to Prof. 0. P. Hay, 

 of the United States National Museum, of Washington, D. C, 

 for the loan of his type specimen of Ichthyodectes cruentus for 

 comparison with some of our specimens, and also for informa- 

 tion on some of the points on which I was in doubt. I must 

 also express my sincere thanks to Mr. W. 0. Bourne, of Scott, 

 and Mr. Travis Morse, of Iola, for the loan of material from 

 their collections of fossil vertebrates; and also to Mr. H. M. 

 McDowell, of this city, for his present of the fine skull of 

 Saurodon xiphirostris. The drawings from which the plates 

 were made were all done by Mr. Sydney Prentice, under the 

 writer's direction. 



Lawrence, Kan., May 15, 1899. 



