The Collaborative International Dictionary of English v.0.48:

Flying lemur \Fly"ing le"mur\ (Zool.)
   either of two nocturnal lemurlike mammals inhabiting the East
   Indies (Cynocephalus variegatus) or the Phillipines
   (Cynocephalus volans) having broad folds of skin between
   the fore and hind limbs on both sides of the body allowing
   them to make long gliding leaps; they have been classed in
   the separate order Dermoptera. They are arboreal and have
   become rare.
   [PJC]

WordNet (r) 3.0 (2006):

Cynocephalus variegatus
    n 1: a variety of flying lemur