TllK MAMMALIA OF TIIF. UINTA FOK.MATIOX. 4'.)7 



tlie ciiiK'ifonn of Protorefdoii may possibly belong to some other genus, though this 

 is not at all probable from the association in wliich it was found. It is much more 

 extended transversely and less antero-posteriorly than in Oreodon, as is also the 

 scaphoid; the ulnar facet is a simple groove which does not descend up(m the outer 

 side of the bone, thus agreeing with OrevJua and differing very markedly from 

 Dicuhjles: the pisifoi-m facet is very large, nearly tlat, and occupies the entire pos- 

 terior surface; the unciform facet is likewise quite diQerent from that of Oreodon in 

 being shallow, of less antero posterior and greater transverse extent. In general the 

 cuneiform of Protoveodon is quite low and broad, with an /-shaped upper contour, 

 highest on the internal or radial side and sloping down towards the external side. 

 Neither trajje/.ium nor trapezoid is represented in any of the specimens, but judging 

 from the facets on the scaphoid, both of these bones were better developed than in 

 Oreodon, implying a larger relative size of the lateral digits. 



The magnum, on the contrary, is smaller and of a somewhat different shape ; the 

 proximal surface is divided nearly evenly between the facets for the scaphoid and lunar 

 which meet at a high angle so as to form a sharp ridge along the superior median 

 line. Seen from the side the upper contour of the magnum forms a ilattcned arch, 

 whereas in Oreodon the magnum is quite low in front and rises abruptly l)ehind, and 

 nearly the whole of the proximal surface is taken up by the facet for the scaphoid. 

 Another difference consists in the long hook-like process which in Protoreodon is 

 given off from the posterior surface of the bone, and which in Oreodon is represented 

 by a mere rudiment. When the l)one is in its natural position the distal surface for 

 mc. Ill presents obliquely downwards and outwards, even more obliquely than in On- 

 odoii. As usual in unreduced artiodactyls there is a small facet on the radial side of 

 the magnum for nic. ii. 



The unciform likewise presents some imijortant dillerences from that of Orrodan. 

 In this genus the lunar and cuneiform facets are of very nearly equal size, while in 

 Protoreodon the latter considerably exceeds the former, as naturally Ibllows from the 

 already-mentioned fact that the lunar rests less completely on tiic unciform than in 

 Oreodon. The surface for the attachment of the cuneiform is less distinctly convex 

 and extends more closely to the external side of the bone than in the Miocene forms. 

 On the distal surface the facet for mc. iv is smaller and that for mc. v larger than in 

 Oreodon, and the latter is more distal in ])ositinn aTul less crowded to the external 

 side V)y the increased development of nic. iv than in Oreodon. This dillerence l)rings 

 about a further one in the shape of the inferior contoui-. which is more i-egularly 

 curved from side to side ami imt so distinctly angulated in /'roOn-f'0(/<>ji. Tiie lat- 

 eral facet for nic. iii i- ui" aliont the same proportions. 



