298 TEESPASSEES UPON THE AIR. 



animal which is popularly called the Opossum Mouse 

 (Acrooates pygmceus) . 



It is barely as large as our common mouse, measur- 

 ing about three inches from the nose to the root of the tail. 

 The tail is as long as the body, and is stiffly feathered on 

 either side ; so that it not only aids in sustaining the 

 body in the air, but also acts as a rudder whereby its 

 course can be directed. The distances through which 

 this beautiful little creature can project itself are really 

 wonderful ; and it can alter its aerial course with so 

 much ease, that most persons who see it for the first 

 time, have some difficulty in believing that it is not a 

 bird. 



A figure of the Opossum Mouse is given on Plate Y., 

 on the same level with the suspended kalongs. 



FLYING SQUIEEELS OF THE OLD WORLD. 



Nature, as well as history, repeats herself. This 

 fact is specially familiar to entomologists, who find the 

 same types of form and colour repeated through many 

 of the various orders. In the mammalia, we have a 

 similar repetition in the flying lemur, which belongs 

 to the monkey tribe; the flying petaurist, which 

 belongs to the marsupials ; and the flying squirrels, 

 which belong to the rodents. 



And, so close is the resemblance, that I am certain 

 that if thirty or forty living specimens of all these 

 three groups were placed in a room wherein they had 

 ample space to exercise themselves, and to display 

 their forms to the best advantage, not one in a hun- 



