TRANSACTIONS OF WAGNER 



58 



UINTA SELENODONTS 



inner one is large, prominent, and rugose; it is not pushed so near to the 

 postero-internal angle as in the oreodonts, but retains an altogether internal 

 position. The anconeal fossa is quite deep and perforates the shaft at one 

 point, making a small supratrochlear foramen. 



The bones of the fore-arm are not anchylosed at any point, at least in 

 the specimens before me, both of which belong to adult animals with com- 

 plete but unworn dentition. The ulna is represented only by a small part of 

 the proximal end, from which a great part of the olecranon has been broken 

 away. So far as it is preserved, it resembles that of Protylopus ; the olecranon 

 is thick and broad, agreeing in proportions with that of the latter, and, as in 

 that genus and in Poebrotherium, the process is continued upward in the line 

 of the shaft, not projecting back of it. Although the coronoid process is 

 prominent, yet the sigmoid notch is not very deep, for its distal portion is 

 not produced forward, the radius occupying the entire breadth of the humeral 

 trochlea. On the outer side, the facet for the humerus is confined to the 

 proximal portion of the sigmoid notch, but on the inner side it is continued 

 downward to the contact with the radius. For the latter there are two small 

 proximal facets, separated by a narrow sulcus. The proximal portion of the 

 shaft is stout and trihedral, with rounded posterior border; of the distal end 

 it can be said only that it is stouter than in Protylopus. 



The proximal end of the radius is quite suggestive of that of the oreo- 

 donts. In correspondence with the form of the humeral trochlea, the head of 

 the radius is narrow, not much wider than the shaft; what little expansion 

 there is, is towards the ulnar side. The articular surface for the humerus is 

 divided into three clearly demarcated facets, the outer one nearly plane and 

 descending obliquely forward, the median one distinctly concave, and the 

 inner one narrower and saddle-shaped ; the dorsal border is raised into a 

 point opposite the median concavity. Proximally, the shaft is narrow, but 

 quite thick and of transversely oval section ; distally, the shaft is slender and 

 the distal end is very moderately expanded, covering the scaphoid and lunar, 

 but apparently not touching the pyramidal. 



The manus (Plate II., fig. 13) is but little differentiated, though not unlike 

 that of Protylopus. The carpus is in such a damaged condition that many 

 important questions regarding it must remain unanswered ; it bears a general 

 resemblance to that of Lcptomcryx, but differs in a number of details, especi- 

 ally in the height of the distal elements. The scaphoid is a large bone, high, 

 broad, and thick ; distally it rests in almost equal proportions upon the trape- 



