SEMNOPITHECUS MAURUS. 
peculiar structure of this tooth among the Quadrumana, first presented itself to me 
in the examination of the Simia Syndactyla (Raff); and in the description of that 
animal, it is represented as having " one high, acute, conical, or pyramidal point, 
projecting considerably beyond the second bicuspidate, with an oblique edge, 
corresponding to the canine tooth in the upper jaw:" and I have added an accurate 
view of this tooth from the materials forwarded from Sumatra by Sir Stamford 
Raffles, and deposited in the Museum of the Royal College of Surgeons, which 
were referred to in the last Number of these Researches. At the same time, I have 
given a detailed view of the general series of the teeth of the adult Siamang, as 
belonging to the Gibbons, the genus most nearly allied to Semnopithccus. I have 
also added, from the Museum of Joshua Brooks, Esq., a view of the teeth of the 
Siamang, as they appear in the young subject. The peculiar structure of the first 
grinder in the lower jaw, as above described, shews itself in all Quadrumana, and 
affords a distinctive character between this order and man. Its degree of develop- 
ment in the Gibbon appears from the annexed Plate. In the various species of 
Semnopithccus it is still more developed, and particularly in the Chingkou and 
in the Kra. In the genus Cercopithecus it exists in the highest degree. M. 
Fre'd. Cuvier, in the work referred to, " Des dentes des mammiferes, &c," has also 
observed and described this structure in the Pongo, (which, according to the 
conjecture of the Baron G. Cuvier, is the adult Orang-utan,) as well as in the 
Cercopitheci and the other Quadrumana of the ancient continent. By systematic 
writers in general it is not mentioned. It requires a more particular degree of 
attention than it has received; and the generic descriptions of the Quadrumana 
hitherto given, are imperfect, as far as regards the character of the first grinder in 
the lower jaw. 
The individuals belonging to the genus Semnopithecus are distinguished, more 
than any other Quadrumana, by a great length of body, and by a slenderness of 
the extremities. In the Simia melalophos, (Raff. ) the Simpai of the Malays, these 
characters shew themselves in the highest degree. The Semnopithecus maurus, 
which is now under consideration, has, on the whole, a stouter make, and more 
robust extremities: it is one of the largest species of this genus; one of the 
specimens in the Museum at the India House, measures two feet and three inches 
from the tip of the nose to the root of the tail. The general physiognomy of the 
animals belonging to this genus is that of the Cercopitheci ; but they have a peculiar 
character in the flatness of the face, and in the attenuated form of the body from 
the breast to the loins. The form of the head of the Semnopithecus maurus is 
already exhibited in the description of the skull : it is lengthened from the forehead 
to the occiput, compressed at the sides, considerably rounded posteriorly, and 
