110 MAMMALS OF THE PACIFIC WORLD 



rillus, Petinomys, Hylopetes, Belomys, Pteromys) are diversely 

 colored. Their sizes vary from that of a mouse (five and one- 

 half inches in total length, of which the tail is half) to that of 

 a rat (about twenty inches, total length). The several genera, 

 many of which are poorly known, are distinguished by dental 

 and skull characters. 



Tree Squirrels 



The tree squirrels are distinguished from the closely related 

 burrowing ground squirrels (see beyond) chiefly for the reader's 

 convenience. They extend east only as far as Celebes. Tree 

 squirrels are typically diurnal forest dwellers. 



Squirrels are sometimes confused with phalangers and tree 

 shrews. Phalangers have very different skulls and teeth and a 

 thumb-like first toe on the hind foot (see phalangers of the 

 Order Marsupialia, p. 23). Tree shrews of China, India, the 

 Philippines, Borneo, and Bali may be distinguished by the num- 

 ber of their incisor teeth — three on each side above and below 

 (see Order Insectivora, Tupaiidas, p. 43). 



The Giant Squirrels (Ratufa) are black, reddish, dirty yel- 

 lowish, with white or yellowish undersides. They reach a size 

 almost as great as the giant flying squirrels, namely, from two 

 to three feet in total length. They are found from the Asiatic 

 mainland to Bali and Borneo. 



Common Oriental Squirrels (Callosciurus) are both abun- 

 dant and very varied. Some are striped above, some striped 

 below, some are variegated black, red and cream, while others 

 are olive-gray above and grayish below. The size of most equals 

 or slightly exceeds that of the North American red squirrel — 

 twelve to fourteen inches in total length, the tail a little less 

 than half. They occur throughout the Malay region as far 

 north as Formosa and east to Celebes. 



Pygmy Squirrels (N annosciurus) are little larger than mice. 

 An exception (N. murinus), found in Celebes, thought to be re- 

 lated to pygmy squirrels, is as large as the common Oriental 



