THE OSTEOLOGY OF ELOTHERIUM. Bl7/ 
side (Kowalevsky, Taf. XXVIJ, Figs, 35). In Anthracotherium (Kowaleysky, 73, 
Taf. XI, Figs. 48, 59) the ectocuneiform is lower and has a more extended connection 
with the second metatarsal. The ectocuneiform of Hippopotamus is low, but very broad, 
in keeping with the great size of the third digit. In Sus this element is not so wide as in 
Lilotherium, and differs from that of all the genera mentioned in having no contact with 
the second metatarsal, from which it is cut off by the articulation of the mesocuneiform 
with the third. 
The cuboid is massive and large in all its dimensions, high, broad and thick. The 
proximal surface is about equally divided between the facet for the caleaneum and that 
for the astragalus, though the latter is slightly the wider. This facet, which is simply 
concave antero-posteriorly, is widest near the dorsal border, and in the middle of its 
course is deeply emarginated from the tibial side. The calcaneal facet is imperfectly 
divided into two parts, of which the dorsal portion is much the larger, particularly in 
width, while the plantar portion curyes inward so as to lie, in part, behind the astragalar 
surface. The cuboid is firmly interlocked with the navicular by means of the deeply 
concave facet on the tibial side near the plantar margin, which receives the projection 
from the nayicular already described. Dorsally the contact between these bones is 
limited to two small facets, one of which is proximal, and the other is distal on the navi- 
cular, median on the cuboid, where it helps to form the projection between the navicular 
and the ectocuneiform ; this prominence is, however, very short. The facets for the 
ectocuneiform are also dorsal and plantar, and are just distal to those for the nayicular. 
The distal end of the cuboid is taken up by the large facet for the fourth metatarsal, that 
for the rudimentary fifth being very small and lateral in position, The plantar hook is 
not long, but is very broad and massive, and bears on its tibial side a facet for the pos- 
terior projection from the head of the fourth metatarsal, 
In Elotherium magnum (Kowalevsky, 76, Taf. XX VII, Figs. 34-36) the cuboid is 
not so high in proportion to its breadth as in the American species, and the tendinal 
sulcus on the fibular side is deeper. The cuboid of Anthracotherium is broader and lower 
and has, of course, a larger and more distal facet for the fifth metatarsal. In Sus similar 
proportions recur, and the division of the calcaneal surface into two parts is complete. In 
Mippopotamus the cuboid is very low and broad, and the astragalar facet is much wider 
than the calcaneal. 
The metatarsus, like the metacarpus, consists of two functional (iii and iy) and two 
rudimentary members (ii and vy). 
Metatarsal [Tis a small nodule, which is much compressed laterally and tapers to a 
point at the distal end; the articulations are proximally with the mesocuneiform and 
laterally with the ectocuneiform and mt. iil. 
