TRANSACTIONS OF WAGNER 



72 



UINTA SELENODONTS 



It is impossible to make out the limits of the lachrymal, or to determine 

 whether a vacuity was present between it and the frontal. 



The frontals are relatively very large bones ; they are both long and 

 broad, but take almost no share in the formation of the cranial roof, for they 

 cease abruptly at the line of the postorbital processes. The temporal ridges 

 thus follow an almost straight transverse course, curving backward very 

 slightly as they approach the median line. The forehead is broad and tri- 

 angular, contracting anteriorly ; it is almost flat, or slightly concave, with a 

 prominent median ridge. The postorbital processes, properly so called, are 

 not very long and but little decurved, but they have the effect of great length, 

 because the forehead and orbits project out widely beyond the sides of the 

 narrow cranium, which is in marked contrast to the condition found in Proty- 

 lopus and much more extreme than that in Leptoreodon. In Leptomcryx a 

 remnant of the same condition may be observed, but the broader and more 

 capacious cranium renders it much less conspicuous. 



The nasals are long, narrow, and convex, slightly so in the longitudinal 

 direction, and strongly so in the transverse. For most of their length they 

 remain of nearly uniform width, and in front their emarginate tips project 

 freely for a short distance beyond the premaxillse. So far as they are pre- 

 served, these nasals agree very well in shape with those of Leptomeryx, but 

 probably do not extend so near to the orbits. 



The premaxillaries are evidently in a state of incipient reduction ; the 

 alveolar portion is very low and short, shorter than in Leptoreodon and much 

 shorter than in Protylopns, and the ascending ramus forms, when seen from 

 the side, a narrow strip along the front of the maxilla, widening a little at the 

 nasal suture. Transversely, however, the ascending ramus is quite broad 

 and contracts the narial opening considerably. This opening is very small, 

 terminal, and nearly erect in position. The palatine processes are small and 

 the incisive foramina narrow. In Leptomeryx the premaxillary has an ascend- 

 ing ramus which is considerably broader (antero-posteriorly) than in the 

 Uinta type, but transversely is very thin and compressed. 



The maxillary is long and low, especially beneath the orbit, and even in 

 front of the latter the facial portion is lower than in Leptomcryx and the 

 edentulous region is decidedly shorter. The muzzle tapers anteriorly and is 

 constricted in front of p A , but is expanded again by the swollen alveoli of the 

 large canines. The palatine processes are long, somewhat concave trans- 

 versely, and almost plane longitudinally. The bony palate is of nearly uniform 



