I30 



CHARACTERS OF VERTEBRATE ANIMALS 



Vn- <\v\, 



related to the Hamster, but its large ears, long tail, and smaller 

 size justify the popular name. It is fawn-coloured above and 

 white below. 



Lemmings resemble voles in many respects, but their tails 

 are even shorter, while their claws are better developed and 

 the fur is much thicker. The best-known species is the Nor- 

 wegian Lemming 

 {Myodes lemm-us) 

 (fig. 89), which in- 

 habits the moun- 

 tain regions of 

 Scandinavia, and 

 from time to time 

 migrates in vast 

 numbers, travelling 

 in a straight line 

 despite all ob- 

 stacles, and ulti- 

 mately plunging 

 into the sea, where 

 it soon perishes, as 

 might be antici- 

 pated. 



The Musquash 



or Musk- Rat {Fiber 



zibethicus), which 



has a wide range 



in North America, 



may be regarded as 



a very large vole, 



thoroughly adapted to an aquatic life, as may be seen by its 



partly- webbed feet and strong flattened tail. It is largely hunted 



for the sake of its fur. 



(2) The Mole-Rat Family includes Old World rodents 

 which have taken to a burrowing life, with the result that 

 their structure has undergone modifications of much the same 

 kind as those exemplified by ordinary moles. A typical species 

 is the Great Mole-Rat (Spalax typhlus), the range of which 

 includes South-east Europe, South-west Asia, and lower Egypt. 



(3) The North American Pouched-Rat Family includes a 



f ig 90. — Kangaroo-Rat {Dipodomys PhiUipn) 



