The flying squirrel, Family Pteromyidae is predominantly an Indomalayan group with 11 genera and 37 species (Corbet & Hill, 1992). The genus Petinomys Thomas, 1908 consists of seven species of flying squirrels which are distributed in India, Sri Lanka, Burma, Thailand, Peninsula Malaysia, Sumatra, Borneo and Mindano (Corbet & Hill, 1992, Lekagul & McNeely, 1988; Medway, 1969, 1977). There are 14 species from eight genera of flying squirrels in Borneo. Four species namely, Petinomys genibarbis, P. setosus, P. vordermanni and P. hageni are recorded in Borneo (Payne et. al, 1985).