1084 The American Naturalist. [ December, 
GEOLOGY AND PALEONTOLOGY. 
On a New Species of Diplacodon, with a Discussion of 
the Relations of that Genus to Telmatotherium.—The ma- 
terial forming the basis of this paper consists of a skull with lower jaw 
(No. 11242, Princ. Collection) found by the writer near the base of 
the Diplacodon elatus beds of Osborn, in the upper Eocene or Uinta, of 
Marsh. The locality is about eight miles north of White River and 
twenty-five miles east of Ouray Agency, Utah, and is locally known as 
Kennedy’s Hole. Other remains of Diplacodon were found, some of 
which are of considerable interest, inasmuch as they establish a lower 
geological range for that genus than has hitherto been accorded it, and 
indicate a considerable variety of species. Remains of Diplacodon are 
among the rarest of all the Uinta mammals, and any material which 
will increase our knowledge of this morphologically interesting genus 
is most acceptable. 
In referring this skull to Diplacodon, I have been compelled to 
ignore certain characters ascribed to that genus by Prof. Marsh. That 
author, in speaking of the relations of this genus to the Titanotheriide 
(Brontotheridze), in his original description of the type specimen, says :* 
“From this family Diplacodon differs widely in its dentition and the 
absence of horns.” In describing Diplacodon as hornless, it would 
seem that Prof. Marsh’s conclusion is entirely conjectural, since his 
material does not show whether there were horns or not. The present 
skull has a well-developed pair of frontonasal horns, and, since it 
agrees in all the characters known to that genus, I have preferred to 
refer it to that genus rather than to propose for it a new one on the 
strength of this purely conjectural character ascribed to Diplacodon by 
Prof. Marsh. Should future discoveries show that there are hornless 
forms with the same dental characters as Diplacodon, it will then be 
necessary to establish for the present specimen a new genus which may 
be called Protitanotherium. 
Diplacodon emarginatus sp. nov. 
The type of the present species is the skull and lower jaw above re- 
ferred to (11242). The posterior region had already weathered out 
when found and was badly injured, but many of the pieces have been 
fitted together and show some of the more important characters of this 
1 Am. Journ. Sci. & Arts, March, 1875, p. 247. 
