Semnopithecus

Semnopithecus is a genus of Old World monkeys native to the Indian subcontinent, in which all species except two are commonly known as gray langurs. Historically only Semnopithecus entellus was recognised, but since about 2001 additional species have been recognised, and the taxonomy has been in flux, with eight species currently accepted. The members of the genus are terrestrial, inhabiting forest, open lightly wooded habitats and urban areas. Most species occur at low to moderate altitudes, although the Nepal gray langur and the Kashmir gray langur live up to 4,000 metres in the Himalayas. The langurs are largely gray, some more yellowish, with a black face and ears, and the species differ mainly in the darkness of the hands and feet, the overall colour and whether a crest is present. Head and body length runs from 51 to 79 centimetres and the tail, at 69 to 102 centimetres, is always longer than the body. Langurs walk mostly on all fours and spend about half their time on the ground and half in trees. Some authors suggest that Trachypithecus is only a subgenus of Semnopithecus, and the purple-faced langur and the Nilgiri langur are placed here rather than in Trachypithecus.