492 



ZOOLOGY 



SECT. 



animals with five- toed plantigrade or semiplantigrade limbs. The 

 tail is usually elongated, and may be naked or covered with fur ; 

 but sometimes, as in the Rabbits and Hares, it is very short. A 

 few special modifications, however, have to be noted in certain 

 families of Rodents. The Flying Squirrels have on each side a 

 fold of skin, the patagium, which serves as a parachute. The 

 African Flying Squirrels (Anomalurus) are remarkable also on 

 account of the presence of a series of overlapping horny scales on 

 the lower surface of the basal part of the tail. The Jerboas (Dipus) 



FIG. 1134. Galeopithecus. (After Vogt and Speeht.) 



and their allies are characterised by the great relative length of 

 the hind-limbs the mode of locomotion of these remarkable 

 Rodents being by a series of leaps not unlike those of the Kangaroo 

 and by the reduction of the number of the toes to three in some 

 of them. The Porcupines (Hystricidce) have numerous elongated 

 spines or " quills " among the hairs of the dorsal surface, and some 

 of them have prehensile tails. The Agoutis (Dasyproctd) and the 

 Capybara (Hydrochcems) have hoof-like claws, the latter having 

 webs between the digits. 



The Insectivora are, in general, small, furry, burrowing Mammals 

 with plantigrade limbs and an elongated muzzle. But there is a 



