386 E. L. Troxell — Entelodonts in Marsh Collection. 



wide process from the temporal; the wide symmetrical 

 dependent process, its position far behind the orbit, the 

 sharp edges of the deeper glenoid cavity, and its geo- 

 graphical location. 9 



The additional features which separate it from the A. 

 crassum gronp as a whole are: the small body of the 

 ramus, the short symphysis, the long diastema, and es- 

 pecially the single-rooted Pi and the small size of it and 

 ofP 2 . 



The second specimen, No. 10290, assigned to this group 

 and referred to the new species, has the single-rooted pre- 

 molar, is similar in proportions, but is a sixth larger than 

 the holotype A. marshi. It differs also in having a much 

 less full angle on the ramus, in having blunt, not slender, 

 coronoid processes, and in having a much wider posterior 

 heel on P 4 . 



8 From the correspondence with L. W. Stilwell concerning the purchase 

 of this specimen, it is evident that . it came from the north bank of the 

 Cheyenne River between French and Battle creeks, and that the horizon is 

 lower Oligocene, associated with Brontotherium and Hyracodon. Further 

 evidence of this is found in the green sandstone matrix and the red stain 

 of the bones so characteristic of the Titanotherium beds. 



TO BE CONTINUED. 



