ch is the type of Christol's genus _Hipparitherium_; and
thus, though _Hipparitherium_ is of later date than _Anchitherium_,
it seemed to me to have a sort of equitable right to recognition
when this address was written. On the whole, however, it seems most
convenient to adopt _Anchitherium_.]

Again, the skeleton of _Anchitherium_ is extremely equine. M. Christol
goes so far as to say that the description of the bones of the
horse, or the ass, current in veterinary works, would fit those of
_Anchitherium._ And, in a general way, this may be true enough; but
there are some most important differences, which, indeed, are justly
indicated by the same careful observer. Thus the ulna is complete
throughout, and its shaft is not a mere rudiment, fused into one bone
with the radius. There are three toes, one large in the middle and one
small on each side. The femur is quite like that of a horse, and has
the characteristic fossa above the external condyle. In the British
Museum there is a most instructive specimen of the leg-bones, showing
that the fibula was represented by the external malleolus and by a
flat tongue of bone, which extends up from it on the outer side of the
tibia, and is closely ankylosed with the latter bone.[1] The hind toes
are three, like those of the fore leg; and the middle metatarsal bone
is much less compressed from side to side than that of the horse.

[Footnote 1: I am indebted to M. Gervais for a specimen which
indicates that the fibula was complete, at any rate, in some cases;
and for a very interesting ramus of a mandible, which shows that, as
in the _Palaeotheria_, the hindermost milk-molar of the lower jaw
was devoid of the posterior lobe which exists in the hindermost true
molar.]

In the _Hipparion_ the teeth nearly resemble those of the Horses,
though the crowns of the grinders are not so long; like those of the
Horses, they are abundantly coated with cement. The shaft of the
ulna is reduced to a mere style ankylosed throughout nearly its whole
length with the radius, and appearing to be little more than a ridge
on the surface of the latter bone until it is carefully examined. The
front toes are still three, but the outer ones are more slender than
in _Anchitherium_, and their hoofs smaller in proportion to that of
the middle toe: they are, in fact, reduced to mere dew-claws, and do
not touch the ground. In the leg, the distal end of the fibula is so
completely united with the tibia that i