Until fairly recently all the Grey Langurs of the south-Asian genus Semnopithecus were lumped as one species, S. entellus. Now they have been split into about seven or eight species. They are distinguished not only by their genetics but also visibly by colouration (especially of the limbs) and by tail carriage (i.e. whether the tail is carried looped forwards or backwards).
I have recently seen four of the species in India (priam, dussumieri, hypoleucos and ajax) so am uploading photos of all four for comparitive purposes.
This pictured species is the Chamba Sacred Langur S. ajax of Himachal Pradesh, in the foothills of the Himalayas. These photos were taken near Dalhousie where they are quite easy to see. There is some disagreement about the extent of this species range, but it is probably restricted to the Chamba Valley.
