Douglass — New Species of Meryeochoerus in Montana. 429 



part of the skull indicating that the head was carried in 

 a nearly vertical or hanging down position. Back part of 

 zygomatic arch small and simple. Length of the alveolar 

 border twice the distance from the last molar to the occipital 

 condyle. Otic bullae not inflated. Mandible heavy and very 

 deep' in the region of the angle. First lower incisor absent. 

 Jaw nearly as deep as skull exclusive of nasals, and nearly as 

 long as the skull at base. 



^h 



&«"««ii/ 



Merycochcerus laticeps. 

 Skull and Mandible, side view, x £. 



Description of Skull. — The premaxillaries are coossified 

 with the maxillaries. Anteriorly the maxillo-premaxillaries 

 are united for a distance of 5'5 cm . Here they form a trough- 

 like depression which becomes broader as it curves gently 

 upward and backward. This widening of the trough is 

 caused by the converging of the ridges from the upper 

 borders of the maxillaries which bound laterally the hori- 



