TRANSACTIONS OF WAGNER 



UINTA SELENODONTS 



greater part of the face; the alveolar portion is very low, but in front of the 

 orbit the body of the bone rises to considerable vertical height, though this 

 height diminishes steadily to the premaxillary suture. The large infraorbital 

 foramen opens above p^. The palatine processes of the maxillaries are long 

 and narrow, and slightly concave transversely ; a deep palatal notch separates 

 the hinder half of the alveolus of m^ from the palatine bone. Along the 

 edentulous portion of the maxillary a low ridge marks the limits of the soft 

 palate. The palato-maxillary suture is not distinctly shown, but appears to 

 be opposite m^, and the posterior nares are placed quite far back, their front 

 margin being on a line with that of m- ; this margin is somewhat raised 

 and thickened and has two short median spines. 



The zygomatic arch is long, despite the posterior position of the orbit, 

 horizontal in position, and decidedly stouter than in Protylopus. The squa- 

 mosal element of the arch is quite long and extends forward to the hinder 

 margin of the orbit; it merely overlaps the jugal and is not received into a 

 notch of the latter, as it is in Protylopus. The jugal is deep vertically, laterally 

 compressed and elongate ; it has no distinct postorbital process. 



Tlie mandible is quite like that of Protylopus, but displays a number of 

 minor differences; its horizontal ramus is long, shallow, and slender, though 

 rather stouter than in the latter, while the diastemata give it a somewhat 

 different appearance; the symphysis is shorter and the chin rather more 

 .steeply inclined, though in Wortman's specimen the symphysis is procum- 

 bent and almost horizontal. The difference may be specific or may be partly 

 due to crushing. . Three mental foramina are visible, a large one beneath pj, 

 and two small ones beneath p^^ and p^ respectively. The ascending ramus 

 of the mandible is broad and the angle is much extended behind the con- 

 dyle, quite as in Protylopus ; the masseteric fossa is placed high up, its lower 

 border being on a line with the molars. The condyle is transversely extended 

 and is raised relatively little above the level of the teeth ; the coronoid process 

 is high, erect, and pointed, but not recurved, and therefore quite different from 

 the ruminant-like form seen in Protylopus. 



The vertebral column, so far as it is preserved, is not especially peculiar; 

 it is represented in specimen No. 11,223 t>y the atlas, axis, and four lumbars. 

 The atlas is quite elongate and seems to be rather narrow, though, as the 

 transverse processes are incomplete, the full breadth of the vertebra cannot 

 be determined. The neural and ventral arches are both strongly curved, 

 eivine to the canal a somewhat circular outline ; the neural arch bears a low 



