FLYING ANIMALS. 31 



consult one of the numerous works on the structure 

 of birds. 



Coming now to the highest class of animals, the 

 Mammals, we shall find that while true flight is only 

 possessed by the whole of the members of a single order, 

 spurious flight occurs among certain members of three 

 widely distinct orders ; and it is curious to notice the 

 remarkable external similarity between some of these 

 animals possessing the power of spurious flight, while 

 they are structurally so different from one another. 



Commencing with spurious flight, the first Mammals 

 we have to mention are the Flying Phalangers of Aus- 

 tralia, which belong to the great order of Pouched or 

 Marsupial Mammals, described in a later chapter, and 

 are closely allied to the so-called Opossums of the 

 colonists. There are several genera of these curious 

 and beautiful creatures, distinguished from one another 

 by the character of the skull and the shape of the para- 

 chute, which may be either very broad or very narrow. 

 This parachute consists of an expansion of the skin of 

 the sides of the body, extending from the wrist of the 

 fore-leg to the ankle of the hind-leg, with a smaller 

 development between the neck and the front of the 

 fore-leg. The Flying Phalangers are strictly nocturnal 

 in their habits, and are able to take enormous flying 

 leaps from tree to tree, during which they descend in 

 the first part of their course, but acquire a slightly 

 upward direction before they alight. 



It is not till we come to the order of Eodents, or 

 those Mammals which, like Hares, Rats, and Beavers, 



