90 
NATURAL HISTORY. 
tint, are brushed, as it were, backwards. Now, an attempt lias been made by Geoffroy St. Hilaire to 
arrange the kinds of Senmopitheci by the direction and peculiarities of their head-dresses, and if 
this plan were carried out the true Douc would bo in one section — that of those with the hair brushed 
back — and the black -legged one, which is only a variety, and not a separate species, would have to be 
placed in another. Hence, this plan is worthless. 
This Douc has a very human face and a small head, a large chest, a thin abdomen, very long 
hind-legs and tail, and short fore-legs. 
The skull of the Douc has large and open orbits, faint side crests, and faint crests passing 
from the ear over the occiput. The face is small in relation to the brain -case, and the shape of the 
whole differs greatly from that of the Troglodytes in this respect. The lower jaw is angular 
behind, and the portion (the ascending branch or ramus) which leads up to the joint is very 
straight. The teeth in it are of the same number as those of the Gibbons ; but the last grinder is 
long, and has a very distinct heel like back, point, or cusp. The other four points, or cusps, are placed 
two in front and two behind them, those in front are united by a cross ridge, then comes a hollow 
across the tooth, and then the back pairs, which are united by a ridge, and then the heel follows. The 
other crushing molar teeth have four cusps, in pairs, each pair having a common cross ridge, and the 
pairs are separated by a furrow. The teeth are close together, and the first false molar is smaller than 
the second. The upper jaw projects a little, and the front jaw-bone (pre-max illary) remains distinct. 
Its crushing teeth have four points, or cusps, but the outline of the teeth is not straight at the 
sides, but doubly curved, so that the entrance of the curves is between the cusps, and it corresponds 
to the furrow. All this gives a very animal look to the teeth. 
It must be remembered that these teeth are used more for crushing soft vegetable matters than 
for cracking nuts, and things which can be stowed away in a cheek -pouch and devoured at leisure. 
Hence the difference be* ween the teeth of these and of the Macaques. 
