306 THE OSTEOLOGY OF ELOTHERIUM. 
The magnum figured by Kowaleysky (76, Taf. XX VI, Figs. 21, 32) is of the same 
general type as in the American species, but with some differences of detail. Thus, the 
bone is of relatively greater antero-posterior thickness; the palmar face is narrower and 
the palmar hook very much more prominent; the sulcus which, on the ulnar side, 
separates the two arms of the lunar facet is much narrower, and, in consequence, the 
arms themselyes are broader; the head of the magnum rises less abruptly toward the 
palmar side. The magnum of Anthracotherium is not sufficiently well known for com- 
parison. That of Hippopotamus is low and broad, and differs from the magnum of 
Llotherium in that the dorsal portion of the lunar facet is proximal in position. In Sus 
also the magnum is low and wide; its lunar facet is relatively larger than in Hippopota- 
mus, and it has no articulation with the second metacarpal, from which it is excluded by 
the contact of the third metacarpal with the trapezoid; the head is low. 
The wnerform is the largest and most massive bone of the carpus; in shape it is low, 
broad and thick, with its principal diameter directed transversely, and has on the palmar 
side a hook-shaped process, which is not very prominent, but broad and heavy. The 
proximal end is occupied by the facets for the lunar and pyramidal, of which the latter 
is much the wider; the junction of the two forms a prominent ridge which curyes across 
the proximal end, from the dorsal to the palmar side. These two facets are both slightly 
concave transversely, but very strongly convex antero-posteriorly, being reflected far 
down upon the palmar face. On the radial side are two vertical articular bands, 
separated by a wide and deep sulcus. The dorsal band, which is much the wider of the 
two, is composed of two very obscurely separated facets, a minute proximal one for the 
magnum anda very large distal one for the unciform process of the third metacarpal. 
The palmar band is a high and narrow facet for the magnum only, and is much more 
extended vertically than the corresponding surface on that bone. The distal end carries 
a large facet for the head of the fourth metacarpal, and on the ulnar side is a minute facet 
for the rudimentary fifth metacarpal. 
The unciform of Kowaleysky’s specimen does not differ in any significant way from 
that of the American species. In Anthracotherium this bone is much wider and lower 
than in Klotheriwm and the facet for the fifth metacarpal is more distal than lateral. In 
Hippopotamus the unciform is exceedingly large, and its dorsal face is of a low, wide, 
rectangular outline, and its great breadth corresponds to the large size and functional 
importance of the fifth metacarpal. The proximal end is divided almost equally between 
the lunar and pyramidal facets, and the absence of a distal beak on the lunar allows a 
larger contact between the unciform and magnum. In Sus, which has much reduced 
lateral digits, the unciform is narrower than in Hippopotamus, but broader than in 
Hlotherium, and the facet for the fifth metacarpal is not so completely displaced toward 
the ulnar side as in the latter. 
