318 THE OSTEOLOGY OF ELOTHERIUM. 
Metatarsal ITT is considerably longer than the corresponding metacarpal and of a 
different shape, being much narrower transversely and thicker in the dorso-plantar dia- 
meter. The head is of moderate width, but the long and massive projection from the 
plantar side gives it great thickness. On the tibial side of the head is a depression in 
which lies the nodular mt. ii. The plantar projection bears a rounded, plane facet on 
each side; that on the tibial side is for the entocuneiform, and that on the fibular side is 
for mt. iv; a second facet for mt. ivy is formed by a shallow depression near the dorsal 
border. The shaft of mt. iii is long, straight and slender; it is flattened on the plantar 
and fibular sides, rounded on the others. Toward the distal end the shaft gradually 
expands both in width and thickness; a very prominent and rough tubercle is developed 
on the fibular border of the dorsal face, just above the trochlea. The latter is rather 
low and narrow and has a prominent carina, which is confined altogether to the plantar 
face. 
Metatarsal TV is a counterpart of mt. iii, with which it forms a symmetrical pair, 
though the plantar projection is even larger and heavier than that of the latter and articu- 
lates with the posterior hook of the cuboid. The connection with mt. iii is by means of 
two facets, the dorsal one a low, rounded prominence which fits into the depression on mt. 
iii already described, and the plantar one on the tibial side of the posterior projection. 
The two metatarsals are held very firmly together, externally by the hook of the cuboid 
and internally by the entocuneiform. A small depression on the fibular side of the head 
lodges the rudimentary mt. y. The shaft and distal trochlea are like those of mt. 111. 
Metatarsal V is even more reduced than mt. ii. It has a thickened club-shaped head, 
which bears a facet for the cuboid and another for mt. iv, the two meeting at a very open 
angle. What remains of the shaft is slender and styliform. The mode of digital 
reduction in the pes, as in the manus, is entirely “inadaptive,” the rudimentary mt. 11 
still clinging to the mesocuneiform and preyenting mt. iii from reaching that tarsal, which 
is much diminished in size, while the ectocuneiform follows the enlargement of mt. 11. 
Kowaleysky found no metatarsals associated with L. magnum. In Anthracotherium 
(Kowalevsky, ’73, Taf. XI, Figs. 45, 55, 59) the lateral metatarsals are still large, fune- 
tional and provided with phalanges ; the median pair are relatively shorter and heavier 
than those of Elotherium, but in other respects resemble them closely. Hippopotamus 
has very short and massive metatarsals, which do not exceed the metacarpals in length 
and which retain the primitive mode of articulation with the tarsals. The metatarsals of 
Sus differ from those of Hlotherium in much the same way as do the metacarpals of the 
two genera. The laterals are still functional, though much reduced, and the medians are 
short and very heavy, with the carinee completely encircling the distal trochlee ; mt. 11 
has acquired an articulation with the mesocuneiform, cutting off mt. 11 from the ecto- 
cuneiform, 
