208 DINOCERATA, 



The type of the 2:)resent species was obtained by Prof. E. D. Cope and 

 Mr. S. Smith, in August, 1872, at Haystack Mountain, Wyoming. 



The remains consist of portions of a skull, and other parts of the 

 skeleton. 



The skull as here figured is in the collection of Prof. Cope. Some 

 other portions of the same skull and skeleton, subsequently collected by 

 Mr. S. Smith, are in the Yale Museum 



Tinoceras cr.assifruiis, Marsh. 



Woodcuts: 30, p. 29; and 182, below. 



FiauBE 182. — Nasiils of Tinoceras crassifrons. Marsh (Xo. 123G). 

 a. side view; 6. top view; c. front view. 



One-flfth natural size. 



Marsh, Fifth Annual Report of the U. S. Geological Survey, (figure from the present 

 volume, viz:) fig. 65, p. 270, 1884. 



The nasals in the type of this species (number 123G) bear small, but 

 prominent, tubercles, directed well upward and outward, and placed well 

 back. In front of these elevations, the nasals are produced, and terminated 

 by oblique, but nearly vertical, sutural surfaces for the pre-nasals. 



The maxillary protuberances are high and prominent, and connected 

 by a transverse, elevated, and sharp, ridge. 



The upper surface of the skull is flattened, and well separated from 

 the lateral surfaces by a ridge, gradually rising into the parietal 

 protuberances. These protuberances are connected by a distinct 

 transverse ridge, and are elevated, and, in section, somewhat triangular. 



The olfactory lobes of the brain were short, and the olfactory 

 chambers Avere not divided by a transverse bony sejjtum. 



The type specimen (number 1236) of tliis species was collected by 

 Messrs. L. Lamotte and J. W. Chew, at Cattail Springs, about twenty-five 

 miles southeast from Fort Bridger, and about eigliteen miles west of Green 

 River, Wyoming, July, 1874. 



