The mammal fauna of the Indian region of Asia is much more highly developed than that of the Palaearctic. The Quadrumana are represented by several peculiar genera, amongst which are Semnopithecus, Hylobates and Simia.
These monkeys are the African representatives of the Indo-Malay langurs (Semnopithecus), with which they agree in their slender build, long limbs and tail, and complex stomachs, although differing by the rudimentary thumb.
A fairly familiar form is the simpei (Semnopithecus melalophus).
LANGUR, one of the two Hindu names (the other being hanuman) of the sacred Indian monkey scientifically known as Semnopithecus entellus, and hence sometimes called the entellus monkey.
In a zoological sense the term is extended to embrace all the monkeys of the Asiatic genus Semnopithecus, which includes a large number of species, ranging from Ceylon, India and Kashmir to southern China and the Malay countries as far east as Borneo and Sumatra.