1896.] Laramie Mammals and Horned Dinosaurs. 113 



History of the Discorert/ of L<imm.i<: Homed Dinosaurs. 



As early as 1872, Professor Cope 1 described under the name 

 of Agathaumas sylvestre a portion of the skeleton of a horned 

 dinosaur from Laramie beds near Black Butte in southwestern 

 Wyoming. In various publications from 1874-1877 which 

 appeared in The American Naturalist, Proceedings Phila- 

 delphia Academy Sciences and Bulletins of the U. S. Geologi- 

 cal Survey, Cope has added much to our knowledge of these 

 strange forms, chiefly from material collected by himself and 

 Mr. Charles H. Sternberg from the vicinity of Cow Island on 

 the upper Missouri River in Montana. 



In 1887 a new locality for horned dinosaurs was found near 

 Denver, Colorado, by Mr. George L. Cannon. The most im- 

 portant specimen, consisting of a pair of horn cores, was sent 

 to Professor Marsh for identification and description. They 

 were not characteristic, and owing to their striking resem- 

 blance to the horns of certain fossil Bisons, they were referred 

 by Marsh to that genus and described under the name of Bison 

 alticornis ; the beds in which they were found being referred 

 to late Pliocene and denominated the Bison beds? 



In 188S the writer secured in the same locality in which 

 Cope had operated in 1875 and 1876 on the upper Missouri, 

 parts of several skulls of a horned dinosaur, some of which 

 Marsh has described, creating for them a new genus Cfrntops. 

 and several new species. A comparison of the types of Cope's 

 Momn;loi tin* reciircicnmis and Marsh's (Vmtop* mo ntamis, both 

 from the same locality in Montana. would doubtless establish 

 the generic identity of the two. 



Not until 1889 was a locality found where remains of these 

 animals were sufficiently abundant and well preserved to afford 

 material which would give us an adequate idea of their struct- 

 ure and habits. In the fall of 1888 the writer's attention was 

 called to a pair of homcores belonging to Mr. C. A. Guernsey, 

 of Douglas, Wyoming. Upon inquiry it was learned that they 

 had been taken from a huge skull found by Mr. E. B. Wilson 



