(Zool.) One of a group of squirrels, of the genus Glaucomys (formerly Pteromus and Sciuropterus [ 1913 Webster ]), especially Glaucomys volans and Glaucomys sabrinus, having parachute-like folds of skin extending from the fore to the hind legs, which enable them to make very long, gliding leaps. [ 1913 Webster +PJC ]

☞ The species of Pteromys are large, with bushy tails, and inhabit southern Asia and the East Indies; those of Sciuropterus are smaller, with flat tails, and inhabit the northern parts of Europe, Asia, and America. The American species (Sciuropterus volucella) is also called Assapan. The Australian flying squirrels, or flying phalangers, are marsupials. See Flying phalanger (above). [ 1913 Webster ]