On the hand and foot, the second digit is reduced, and moves somewhat in the same plane as the thumb, making the hand and foot like pinchers. This needed for the slow methodical movement they employ. This species also has a relatively small tail. They have a dental comb for grooming. On the second digit of the feet the nail is modified to form a toilet claw used for scratching and cleaning the auditory canal. This toilet claw is always licked clean after use (Schulze and Meier, 1995b). The slender loris has a dental formula of 2:1:3:3 on the upper and lower jaws (Hill, 1933). The canines are incisiform (Hill, 1933). The second upper premolar is molariform in shape (Hill, 1933). In the lower jaw a slight diastema separates the canine from the first premolar (Hill, 1933). the third premolar of the lower jaw is molariform (Hill, 1933). The eyes of the slender loris are fixed in a way so that it must move its head to achieve focus; the eyes also have a tapetum to help see in the dark. The bones of the limbs are unusually long and thin (Hill, 1933). The index digits of both the hands and feet have one less phalanx than normal (Hill, 1933). The clitoris of the female is as long or longer than the male penis (Hill, 1933). Females have two pair of mammae (Hill, 1933). This species has an unusually low metabolic rate (Schulze and Meier, 1995b). The average body mass of an adult slender loris is between 227 and 355 grams (Petter and Petter-Rousseaux, 1979). The iris of this species has a chestnut-brown tint (Hill, 1933). The slender loris has a moderately developed nictitating membrane (Hill, 1933).