252 Mammals of Eastern Asia 
large and relatively naked. The length of head and body is about 
5% inches, tail 6% inches, foot 1% inches. 
Horsfield's Flying Squirrel was first made known from Java 
or Sumatra. One continental race, davisoni, occurs in Malacca 
at the southern end of the Malay Peninsula and a second, 
penangensis, from Penang Island. Other related forms are 
Bornean. 
SUPERFAMILY CASTOROIDEA 
THE BEAVERS (FAMILY CASTORID^) 
The single living genus of Beavers, Castor, circumpolar in 
distribution, is found in the temperate parts of America, 
Europe, and Asia, though not near the extreme northeastern 
coasts of Asia. Beavers look a little like aquatic Woodchucks 
with broad, flat, paddle-like tails. The hind feet are completely 
webbed. The fourth hind claw, which seems to be double, may 
be used in combing the fur. The forefeet, though small, have 
Fig. 56. Beaver, Castor fiber. 
