308 THE OSTEOLOGY OF ELOTHERIUM. 
In £. magnum, Kowaleysky’s figure shows a somewhat differently shaped proximal 
end (76, Taf. XX VI, Figs. 21, 24), the head is somewhat more extended transversely, 
especially toward the ulnar side, while the palmar projection is narrower and_ less 
prominent. In Anthracotheriwm the head of me. iii has no such transyerse extension. 
Metacarpal V is an almond-shaped nodule, almost exactly like the specimen figured 
by Kowalevsky (Taf. XX VI, Fig. 25), though of a rather more regular outline. Proxi- 
mally the nodule has quite a large, subquadrate, and slightly concave facet for the unci- 
form, which presents more laterally than superiorly, and forming a very obtuse angle with 
this surface, is a smaller, triangular facet for me. iy. 
The metacarpus of Hippopotamus has four functional members, though the median 
pair are longer and stouter than the lateral. Compared with those of /lotheriwm they 
are relatively shorter and much heayier. In Sus there are also four metacarpals, but 
the laterals are much reduced, while the median pair, which carry most of the weight, 
are yery short and thick, and the distal carina surrounds the entire trochlea, dorsal as 
well as palmar. The mode of articulation between the carpals and metacarpals is 
quite different from that found in either Hlotherium or Hippopotamus, the head of 
me. iii being much broadened and articulating extensively with the trapezoid, so that 
me. ii is cut off from any contact with the magnum. This is what Kowaleysky has 
called the “adaptive method” of digital reduction, and it is in decided contrast to the 
inadaptive method exemplified in L/otheriwm. 
The phalanges, which are quite short, as compared with the length of the meta- 
earpals, are developed only in the median pair of digits. The proximal phalanx of 
digit iii is relatively elongate, straight, broad and depressed ; its proximal end is both 
wide and thick, and carries a concaye facet for the metacarpal trochlea, which is deeply 
notched on the palmar border for the carina. Toward the distal end the phalanx 
narrows but little, though diminishing much in the dorso-palmar diameter; the distal 
trochlea is low, wide, depressed and only slightly notched in the median line. The 
second phalanx is short, broad and thick, and of quite asymmetrical shape ; its proximal 
trochlea is obscurely divided into two facets, of which that on the radial side is the 
larger and extends more in the palmar direction, while the median dorsal beak is not 
prominently developed. The distal trochlea is much thicker than that of the first 
phalanx, is reflected much farther upon the dorsal face, and is more distinctly notched 
in the median line. The course of this surface is oblique, so that it faces somewhat to 
the ulnar side. The ungual phalanx is curiously small and nodular in shape, and is 
short, but quite broad and thick; the proximal trochlea is imperfectly divided into two 
slightly coneaye facets. The palmar surface is nearly plane, except for its rugosities, 
while the dorsal margin descends abruptly to the blunt distal end. 
