Douglass : Vertebrates from Montana Tertiary. 193 



of the corresponding teeth of A>/ipJu\-yon //lajor which is figured in de 

 Blainville's Osteographie. 



The face is short and the teeth crowded together without disaste- 

 mata. The last three i)remolars are preserved and there appears to 

 have been a small first premolar. A part of the posterior portion of 



Fig. 31. Dinocyon ossifragiis {l>io. 790). Lower Madison valley. One fourth 

 natural size. 



the alveolus of the canine is present and is but a slight distance in 

 front of P-. What appears to be a small portion of the alveolus of 

 pi is also preserved, but it must have been small and crowded be- 

 tween the canine and P^. The posterior portion of the skull, espe- 

 cially the mastoid portion, is massive. The mastoid and postglenoid 

 process are bear-like, while the teeth have the general pattern of those 

 of the dogs, but are low, strong, blunt, and simple, as if formed for 

 grinding and crushing rather than for cutting. The worn condition 

 of the teeth shows further evidence of this. 



There is a deep concavity in the face posterior to the root of the 

 canine and anterior to the infraorbital foramen. The foramen opens 

 into this concavity. It is above Pi, is oblong-elliptical, and opens 

 forward and upward. 



Just above the foramen magnum the occipital projects backward and 

 is separated into two lateral concavities by a deep median groove. 

 The occipital condyles are broad and the articular faces quite widely 

 separated below although this character is not shown in the figure. 

 The basioccipital has a sharp narrow median ridge and there are two 

 lateral convexities about one inch forward of the condyles. 



