342 SCOTT. [Vol. XL 



as the dividing ridge crosses the head obliquely, this region is 

 more equally shared between the two facets. The lunar facet 

 is much narrower than that for the scaphoid ; in front it is 

 more decidedly concave and is lateral rather than proximal in 

 position ; on the head, however, the surface which supports 

 the lunar is truly proximal. On the radial side the small 

 facets for the trapezoid and second metacarpal meet at an 

 open angle and form a salient edge. The distal surface is 

 occupied by a large saddle-shaped facet for the third meta- 

 carpal, and rising from this a small one for the second. 



The unciform is a large bone, though smaller than the 

 scaphoid, which exceeds it in every dimension save that of 

 thickness ; it is, however, notably high in proportion to its 

 width. The posterior hook, which in the Pecora, including 

 even Moschus, is rudimentary, is still well developed, though 

 smaller than in many ancient forms of the Artiodactyla, e.g.^ 

 AncodiLS. The proximal surface has two facets, a narrower 

 one for the lunar and a much broader one for the cuneiform. 

 The former is low and slightly concave in front, rising behind 

 into a convex head like that of the magnum. The cuneiform 

 facet is continued down over the ulnar side of the bone, almost 

 reaching the surface for the fifth metacarpal. The magnum 

 surface is confined to a minute strip near the dorsal side, 

 above the facet for the third metacarpal. The latter facet is 

 much more extensive than in those Pecora in which the meta- 

 carpals have coalesced to form a cannon-bone and is even 

 larger than in Gelociis. The distal surface is taken up by the 

 large facet for the fourth metacarpal ; that for the fifth is very 

 much smaller and rather lateral than distal. 



The Metacarpus (PI. XXII, Fig. 17) contains four elements. 

 The median pair (III and IV) have attained about the same 

 stage of development, as regards length and slenderness, as in 

 Gelocus, and are therefore relatively longer than in the more 

 ancient artiodactyls, XipJiodo7t excepted. The laterals (II and 

 V) have at the same time retained a size and importance which 

 is utterly unknown in the Pecora and far exceeds what is 

 found in the tragulines. All of the digits remain free through- 

 out life. The mode of connection between the carpus and 



