304 THE OSTEOLOGY OF ELOTHEKIUM. 



project over the pyramidal. The lunar of Anthracotherium (see Kowalevsky, '73, Taf. 

 XI, Fig. 37) is like that of Eloth&rium, but is narrower, especially its palmar face, and 

 much thicker, and the distal beak is more nearly in the median line. In Hippopotamus 

 the lunar is broad and rests almost equally upon the magnum and the unciform, as it 

 does also in Sus. 



The pyramidal quite resembles the scaphoid in shape, but is much broader, not so 

 thick antero-posteriorly, and generally of a more rugose and massive appearance. In 

 view of the reduced lateral digits and the coiissified radius and ulna, the relatively large 

 size of the pyramidal is somewhat surprising. The proximal end is occupied by the 

 ulnar facet, which is convex transversely and deeply concave antero-posteriorly. On the 

 palmar side is a narrow, plane facet for the pisiform, which is very oblique in position. 

 This facet is carried upon a compressed and slightly recurved, hook-like ridge, which 

 runs for nearly the full vertical height of the bone, though not quite reaching to the 

 distal end. < )n the radial side are two facets fur the lunar, separated by a wide and deep 

 sulcus; the palmo-distal one is larger than the corresponding surface on the lunar, and 

 its curvatures are, of course, in opposite directions to those of the latter, being concave in 

 the vertical, and convex in the dorso-palmar diameter. The distal end of the pyramidal 

 is taken up by a large, hut slightly concave facet for the unciform. 



In the material described by Kowalevsky the pyramidal of Elotherium is not repre- 

 sented, while that of Anthracotherium is so badly preserved and of such uncertain 

 reference, that any comparison founded upon it would lie valueless. The pyramidal 

 of Hippopotamus is broad, square and heavy, as is also that of Sus, on a smaller scale. 



The pisiform is quite small and slender, though of considerable length; it is strongly 

 recurved toward the median side of the carpus, presenting the convexity externally; the 

 distal end is thickened and club-shaped, though but little expanded in the vertical 

 dimension. The pyramidal facet is nearly plane and oblique in position, broadest exter- 

 nally and narrowing to a point on the radial side. The ulnar facet is very much smaller 

 and somewhat concave: the two meet at almost a right an«>"le. 



The pisiform of K. magnum (Kowalevsky. 76, Taf. XXVI, Fig. 27) is not unlike 

 that of /.'. ingens, hut is of a more irregular shape, which looks as though it might be 

 due to disease, that of Anthracotherium (Kowalevsky, '73, Taf. XI, Fig. 58) is of quite 

 similar shape, though much larger. In Sus the pisiform is of an entirely different shape 

 from that of either of the extinct genera, being much deeper vertically, more compressed 

 and plate-like, and less strongly recurved. That of Hippopotamus is more like that of 

 the fossil forms. 



The trapt --'nini is not associated with any of the specimens which I have seen, nor is 

 any facet for it distinctly visible on either the scaphoid or the trapezoid. If present at 



