208 



Annals of the Carnegie Museum. 



The Manus. — Only the scaphoid, trapezoid, and the third and fifth 

 metacarpals of the right manus are preserved in the type. 



The scaphoid shows some marked differences from that of P. car- 

 rikeri. While the vertical^^ and transverse diameters are very nearly 

 the same in the two species, the antero-posterior diameter of P. van- 

 tasselensis is very much less, the palmar protuberance being very 

 much less developed. The articulation for the radius is more deeply 

 concave antero-posteriorly; the anterior ridge somewhat narrower, 

 but the antero-external angle rises in about the same manner to form 

 the high, overhanging crest, which fits into the deep oblique groove 

 of the scaphoid facet of the radius. The inferior facet for the lunar 



I a 



3 4 



34 35 



Fig. 34. Scaphoid of Promerycochoerus vantasselensis. No. 



I. dorsal view; 2, radial view; 3, proximal view; 4, distal view. 

 Fig. 35. Trapezoid of Promerycochcerus vantasselensis. No. 1230; ^ nat. size. 

 I, radial view; 2, dorsal view; 3, proximal view; 4, distal view. 

 Fig. 36. Metacarpals oi Promerycochoerus vantasselensis. No. 1230; | nat. size. 

 I, dorsal view of metacarpal V, right manus; 2, dorsal view of metacarpal III, 

 right manus; 3, radial view of metacarpal III, right manus. 



takes up a considerable part of the external face and above there is a 

 small facet indicating a contact with the lunar, which is not present 

 in P. carrikeri. Distally the scaphoid has the facet for the trapezoid 

 located more laterally, causing the bone on the radial side to appear 

 more compressed than is the case in P. carrikeri. There is no facet 

 for the trapezium. 



The trapezoid is relatively smaller, but otherwise there is no dif- 

 ference in shape from that of P. carrikeri. The facet for the tra- 

 pezium is large, and occupies the postero-lateral angle, extending from 

 near the proximal to the distal face, forming a sharp angle with the 

 facet for the second metacarpal. Mc. Ill has the same general pro- 



'8 In passing it may be noted that the vertical diameter of the scaphoid in 

 Mesoreodon, though a smaller animal, is veiy nearly as high as in this species. 



