J 5 2 



RODENTS. 



Northern Pocket- The northern pocket-gopher (Thomomys talpoides) is the best 

 Gopher. known representative of a second genus, containing at least two 

 species, and distinguished by the absence of grooves in the upper incisor teeth. 

 This species measures from 6 to 8 inches in length, and the tail some 3 inches 

 more : while its general colour is very similar to that of the brown rat. The 

 animals of this genus are distributed over the whole of Canada ami North America 

 west of the Rocky Mountains. In habits they precisely resemble the preceding 

 genus. 



The Kaxgaroo-Rats. 



Genus Dipodomys. 



The kangaroo-rats and their smaller allies the pocket-mice are utterly unlike 

 the pocket-gophers in external appearance, having elongated hind-limbs and tails, 



THE COMSIOX KAXGAKOO-RAT (\ Wit. dze). 



large eyes, and well-developed ears, while their habits resemble those of the 

 jerboas. They agree, however, with the former in the possession of large external 

 cheek-pouches, and their general internal structure, although their upper incisor 

 teetli are proportionately much narrower, and there are certain peculiarities in the 

 conformation of the skull. 



common The kangaroo-rats are characterised by the molar teeth being 



Kangaroo-Rats, rootless, and their best known representative is the common species 

 (Dipodomys phUlipsi) depicted in our illustration, which inhabits the desert 

 regions to the eastward of the Rocky Mountains, and is characterised by the 

 possession of four toes on the hind-feet. The head and body of this animal 

 measure a little over 4 inches in length ; while the tail is very long and tufted 

 at the end, and the general build of the creature light and elegant. The colour of 



