THE OSTEOLOGY OF ELOTHERIUM. 303 
facets on both bones are more or less prominent, they are elsewhere separated by con- 
siderable interspaces. The distal side of the scaphoid is much narrower than the 
proximal and is occupied by facets for the trapezoid and magnum, no articular surface 
for the trapezium being apparent. The trapezoidal facet is considerably the smaller of 
the two, and is simply concave. The magnum facet is in two parts, a very slightly 
concave distal portion, and a somewhat smaller lateral portion on the ulnar face of the 
scaphoid. 
In the European species figured by Kowalevsky (’76, Taf. XX VI) the scaphoid is 
somewhat broader than in the American forms, In both groups a remarkable resem- 
blance to the scaphoid of Anthracotherium is observable, which extends to even the details 
of structure (see Kowalevsky, ’75, Taf. XI, Fig. 38). As Anthracotherium is, however, a 
tetradactyl form, the scaphoid is somewhat broader in proportion to its height than that 
of Elotherium, though hardly so much so as would be expected. In Hippopotamus and 
Sus the scaphoid is of quite a different shape from that of the fossils, being distinctly 
shorter and wider. 
The /unar is a very large and complex carpal, which exceeds the scaphoid in all of 
its dimensions, and especially in breadth. The radial facet is in two parts, continuing 
those which occur on the scaphoid ; the anterior or dorsal part extends across the width 
of the bone and is very convex antero-posteriorly, while the palmar portion is very much 
larger and is concave in the same direction. The dorsal border rises steeply toward the 
ulnar side, where the lunar is drawn out into a blunt, projecting, hook-like process, which 
extends over the pyramidal, as the scaphoid does over'the lunar. On the radial side are 
three facets for the scaphoid, corresponding to those on the latter, which have already 
been described. The palmar face is greatly extended transversely, and, though lower, is 
much broader than the dorsal surface. On the ulnar side are two facets for the 
pyramidal, which constitute an interlocking joint of unusual firmness and strength. One 
of these facets is proximal and dorsal and overlaps the pyramidal; the second, which is 
very much larger, is palmar and distal in position, and has a saddle-like shape ; it interlocks 
closely with a similar facet upon the pyramidal. When seen from the front, the contact 
between the lunar and the magnum appears to be entirely lateral, but as it passes toward 
the palmar side, the magnum facet broadens, becomes very concave, and assumes a distal 
position. The unciform facet is aiso oblique and the beak between the two is not in the 
median, but shifted far toward the radial side. Dorsally the unciform facet is consider- 
ably wider than that for the magnum, but on the palmar side these proportions are 
reversed. 
The lunar of L. magnum figured by Kowalevsky resembles that of EZ. ingens, except 
that its proximal surface does not rise so steeply toward the ulnar side and does not 
A, P, S.—VOL. XIX. 2M, 
