296 The Rodentia. 



seasons of the year it is very abundant, moving from place 

 to place in hordes of thousands, destroying the vegeta- 

 tion in its path until stopped by the sea or some other 

 natural obstacle to its further progress. According to a 

 writer in the Century Dictionary : " so numerous are these 

 animals at times and so sudden is their appearance that 

 they are fabled to rain down from the clouds." Large 

 numbers of rapacious quadrupeds and birds hang upon 

 their line of march, and materially diminish their numbers. 



There is a kind of false Lemming in British America, 

 and parts of the United States from Indiana and Kansas 

 to Alaska, but the only true Lemming on the Western 

 Hemisphere is the Hare-tailed Mouse (Cuniculus-hudsonius 

 or -torquatus) , a species which turns snow-white in winter, 

 and is found only in Greenland and the Hudson's Bay 

 regions. 



The fur of the Lemming is of little value, being used 

 only for cheap linings. 



The Water Vole (Avicula-amphibius), commonly called 

 the Water Rat, whose habitat is in England and France, 

 is a fur-bearing animal although its skins are not used for 

 fur purposes. It is an aquatic mammal, resembling the 

 muskrat in form and habits, and living, like the European 

 Beaver, in holes in the banks of ponds and rivers. It is 

 strictly vegetarian, subsisting on the roots of plants, fallen 

 apples and pears, and the bark of trees. Black specimens, 

 and also white are sometimes seen, but generally the 

 Water Vole has a greyish brown coat with a blue under- 

 fur like that of the muskrat, which it resembles in so many 

 ways that some authorities think it may prove to be the 

 same animal. 



The Beaver Rat (Hydromys-chrysogaster) , sometimes 

 called the Golden-bellied Rat, is one of the few Australian 

 mammals which possess a thick under-fur. On the back 

 it is very much like the ordinary rat in color, but the fur 

 on the belly is a golden or light grey hue, like that on the 

 muskrat. The length of the body is about eight inches, 

 and the six inch tail is very dark grey or black in color,, 

 except the part nearest the top, which is white. 



