DESCRIPTION OF THE LIMBS 
i5 
Astragalus. — The astragalus (PL VI, figs. 1 a, 2 a) is very low and broad as 
in E. antiquus recki; the tibial facet is scarcely perceptibly concave from side to side. 
On the whole, the bone is much like that of E. maximus and E. primigenius, and 
differs from the astragalus of E. africanus in the greater development of what may 
be called the neck, which carries the facet for the navicular ; in E. africanus this 
neck is practically absent on the outer fibular side of the bone. The postero- 
internal angle extends further back than in E. primigenius and E. africanus ; it 
terminates in a large boss of bone continuous with that on the inner side. In this 
respect the astragalus of E. maximus is most similar. The sustenactular (ental) 
facet is continued further back than in E. primigenius, E. africanus, and E. antiquus 
recki, being much like what is seen in E. maximus, the astragalus of which on 
the whole most nearly resembles our specimen. The ectal facet is at a higher 
level than the sustenactular ; these two facets are almost equal in size, while in 
E. antiquus recki the ectal is considerably the larger, as this seems to be the more 
usual condition. The navicular facet makes an angle a little greater than a right 
angle with the sustenactular facet and the angle between a line drawn at right 
angles to the chord of the tibial facet, i.e. in the direction of the long axis of the 
tibia, and a line at right angles to the navicular facet (Dietrich’s normal angle of 
the joint) is about i20°-i25°. If this angle is correct, and it is by no means easy 
to get certain results in making such measurements, then it would seem that the 
long axis of the hind-foot is not so nearly in the same straight line with the long 
axis of the tibia as it is in E. antiquus recki, and still less so than in Dinotherium. 
This, in an animal of such massive proportions, is not what one would have 
expected. 
Calcaneum (PI. VII, figs. 1 a, 2 a). — The calcaneum is preserved on both sides ; 
it is a very heavily built and massive bone. The tuber calcis is short and deep, 
and the rugosities that terminate it are very strongly developed. Of the facets for 
the astragalus the ectal is nearly flat, while the triangular sustenactular facet which 
is at a rather lower level than the ectal, has a gently undulated surface. The 
groove between these two facets deepens to a pit in the middle of its course. The 
fibular facet makes an angle of about no° with the ectal. The facet for the cuboid 
is concave from befofie backwards ; the chord of this concave surface makes as 
nearly as possible a right angle with the ectal facet. In E. primigenius and 
E. maximus the cuboid facet is slightly concave towards its posterior border; in 
E. africanus the concavity is rather more marked, but still much less so than in 
our specimen. 
The facet for the navicular is nearly circular in outline ; it makes an angle 
of iio° with the sustenactular facet. It most resembles the same facet in 
E. primigenius ; in E. africanus and E. maximus this angle is more obtuse, and the 
surface relatively more elongated from side to side. The calcaneum of E. antiquus 
recki has much the same proportions as that now described, but in it the ectal 
facet is much larger than the sustenactular. On the whole, our specimen most 
nearly resembles the calcaneum of E. africanus, except that the fibular facet is 
smaller. 
