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 Tufted Grey Langur S. priam of Sri Lanka and southern India. There are two subspecies, priam in India and thersites in Sri Lanka. These photos were taken at the Chinnar Wildlife Sanctuary in Kerala (India) and some authorities are of the opinion that this particular population is also thersites rather than priam as elsewhere in India.
