These two species are readily distinguished by the amount of hair on the ventral surface of the body. In P. stangeri the ventral surface is thinly haired, often almost naked, a rare feature in the order Rodentia, whereas in P. aubinnii the belly is well furred. The tail is bushy and often somewhat longer than the head and body. The ears are small and rounded. The pelage is coarse.
Females have four pairs of mammae.
These squirrels live in high forest and are mainly arboreal but sometimes forage on the ground. They shelter in tree cavities. They have been described as active and agile. When not disturbed, they utter a birdlike twittering call. Seeds, nuts, and fruits make up their main diet, and in some areas they feed extensively on the orange-colored nuts of the oil palm, which often stain the pelage.