P T E R M Y S. 



503 



powerful cross motion to the fore legs, so that these 

 can be thrown outwards nearly at right angles to the 

 axis of the body. The hind legs also are capable of 

 very wide motion. In their system of teeth, their 

 organs of sense, their mode of reproduction, and, 

 generally speaking, in all the essential parts of their 

 organisation and habits, they are true squirrels : and 

 the description of them thus far may be referred to 

 the article SQUIRUEL. There is even, in some of the 

 other squirrels, a slight approximation to what forms 

 the distinguishing character of the present genus : 

 the bodies of these are fiat, they can spread their feet 

 wide, and the skin of their sides stretches a little near 

 the fore legs and flanks to break their fall. In the 

 present genus the skin is regularly extended from the 

 tore legs to the hind ones, covered with thick and 

 soft Cur, and ibrminir a most efficient parachute. There 

 is also a particular bone attached to the foot, for sup- 

 porting thi* membrane ; so that, though this peculiar 

 formation cannot bo said to originate any of the mo- 

 tions of the animals, it enables them to leap much 

 farther from branch to branch than it' they had no 

 extensile skin, on the sides. This alone entitles them 

 to be considered as a distinct group, and as such they 

 are u very well marked one. 



We need not say that these animals do not fly, or 

 that the word flying is inaccurately applied to them ; 

 for there is no instance of a vertebrated animal per- 

 forming real flight by the motion of any other bones 

 tlmn those of its anterior extremities. These animal* 

 can no more take a second leap, or gain a fresh im- 

 puKo from the air as a fulcrum, than the heaviest of 

 the mammalia ; they can merely leap to a great dis- 

 tance, and it is this which is their habit in enabling 

 them to pass from tree to tree, over considerable 

 openings in the forest, without descending to the 

 ground. We need not add that they are forest ani- 

 mals, because the apparatus with which they are fur- 

 nished woidd be an incumbrance to an animal in any 

 other locality. They are not found in the wooded 

 countries of all parts of the world, but they range 

 considerably in latitude, being found in polar conn- 

 trie.*, and also in tropical ones. They are met with 

 in the woods of Canada and the United States, though 

 not in the tropical or southern parts of America. 

 Some of them occur in Lapland, and along the north- 

 ern forests of the eastern continent, as far as the 

 eastern part of Siberia. They are met \vit,h again in 

 India, and in Java and some other of the eastern 

 islands ; but in Australia their place is occupied by 

 those marsupial animals with laterally extended skin 

 to which we have alluded. 



Some naturalists have divided them into two sec- 

 tions or snbenera, according- as they have the tail 

 round, or broad and flat like that of the squirrel. 

 The name Pteromy.i has been restricted to those with 

 the round tails, from that being the form of the tail in 

 a mouse ; and those with the flat tails have been 

 called Sciurop tents, or flying squirrels. The two 

 divisions are pretty distinct from each other, bo,lh in 

 this character of the tail, and in the nature of the 

 places where they inhabit. Those with the round 

 tails are larger and more handsome animals than 

 those with the flat ; and they are met with only in 

 the warmer parts of America, and in the Asiatic 

 islands ; the flat-tailed ones are smaller, less hand- 

 some, and chiefly, if not exclusively, found in cold 

 countries. 



PTIROMYS. The tails in these are round, and 



the hairs do not stand out distinctly from each other. 

 There are several species ; but the nature of their 

 haunts, and the rapidity with which they make their 

 way among the thick branches of the trees, leaping 

 fearlessly and smoothly where they cannot run, ren- 

 ders the study of their habits very difficult, and the 

 consequence is that but little is known concerning 

 them. 



P. petaurista. This is the sailing squirrel, and also 

 the great flying squirrel of the oriental isles. In the 

 native language of the Malays it is termed Jaguar. 

 The upper part of its body is brown, mottled with 

 white ; the under part greyish white, and the under 

 side of the tail more or less brown, though above it is 

 black for nearly the whole of its length ; the thighs 

 are red, and the feet brown ; the borders of the 

 mouth and around the eyes are blackish, the musta- 

 chios are black, and the cheeks and top of the head 

 are mottled brown and white. The flying membranes 

 form salient angles at the wrists, and there is a small 

 rudiment of a membrane at each side of the base of 

 the tail, united to the insides of the thighs, preventing 

 the escape of the air in that way when the animal 

 leaps. This is rather a large animal for the family 

 to which it belongs, the head and body being about 

 a foot and a half long, and the tail nearly one foot 

 nine inches. It is understood that the habits of this 

 animal are nocturnal, but very little is known of them. 

 It occurs in the Molucca islands, the Philippine, and 

 various other groups in the Eastern seas. 



P. iritidns the bright flying squirrel. This species 

 inhabits the same part of the world as the former, 

 though perhaps a little more to the westward, being 

 more numerous in Java than in the isles further to 

 the east. Its form and size are very similar to those 

 of the preceding species, only it is, generally speak- 

 ing, an inch or two shorter. Its colours are different, 

 which makes its chief distinction, for its manners are 

 just as little known as the other. The upper part is 

 dark brown, and the under bright red. The tail is 

 the same red as the under part at its base, but gets 

 deeper toward the extremities. It is probable that 

 this one is subject to some varieties of colour, because 

 specimens have been met with agreeing with it in all 

 their other characters, but having the belly white. 

 There are some other species in the oriental islands, 

 but they appear to belong to the flat-tailed section. 



SCIUROPTERUS. The animals of this section have 

 the teeth exactly like the common squirrels, while those 

 of the former section have them different. In that 

 section the teeth are simple teeth, without showing 

 any layers of cortical matter, alternating w ith enamel 

 in the crowns ; and of course they indicate a differ- 

 ence in feeding, though it is not known in what the 

 difference consists. The present section, which have 

 cheek teeth like the squirrels, must of course be 

 understood to feed upon the same substances and in 

 the same manner as squirrels do. 



S. snjitta. This species is found in Java and the 

 adjoining islands, and differs from those of the former 

 section in size, as well as in the structure of the teeth 

 and in the form of the tail. It is only five or six 

 inches long in the head and body, and nearly the 

 same in the tail. Its prevailing colours are brown 

 on the upper part, and white on the under. The 

 lateral membrane forms a sharp saliant angle behind 

 the rest, the same as in the animals of the former 

 genus. 



S, genibarbis, called Kechubu in Java, is about the 



