118 The American Naturalist. [February, 



time of the deposition of the Laramie beds of the Judith River 

 and Black Butte localities, marine beds with Fox Hills types 

 of fossils were being deposited over the region of what is now 

 eastern and central Wyoming. This would account for the 

 absence in this region, of the lower Laramie, with the smaller 

 and less specialized horned, and other dinosaurs, characteristic 

 of it. 



Other Localities for Horned Dinosaurs. 



In addition to the localities already mentioned, the writer 

 has seen remains of horned dinosaurs and Hadrosauridse on 

 the North Platte River opposite the mouth of the Medicine Bow, 

 about 35 miles below Fort Steele, Wyoming ; along the eastern 

 flank of the Big Horn Mountains about 40 miles south of Buf- 

 falo, Wyoming ; on the west side of the Big Horn River between 

 Fort Custer and Custer Station, Montana ; and on Willow Creek 

 13 miles north of Musselshell postoffice in Montana. Another 

 region not examined, but which looked very promising, is 

 near the town of Havre on the Great Northern Railroad just 

 north of the Bear Paw Mountains in northern Montana. 



Suggestions to Collectors. 



Of all the localities for Laramie dinosaurs and mammals 

 known to the writer, that of Converse Co., Wyoming, is by far 

 the most promising, and the earnest and intelligent collector 

 will there meet with a fair amount of success for many years 

 to come. As will be seen, by reference to the map accompany- 

 ing this paper, this region is easy of access from the town of 

 Lusk on the F. E. and M. V. R. R. At this station all neces- 

 sary camp supplies can be obtained. The fossil beds are easily 

 worked, the country being quite open and its surface not dis- 

 figured by deep and impassable canons. There is abundant 

 grass for horses, wood for fuel, and frequent small springs of 

 fairly good water. 



Vertebrate fossils are never abundant in the Laramie, but 

 every exposure in this region should be carefully searched and 

 especially the large sandstone concretions which contain many 



