38 



Beavers, their houses and dam. 

 From D. Applrton ft Co.'s •' Element* of Zoolosy. Science Series." 



GROUP 88.— The Mick, Rats. &c, Family MuricUe. 

 This family presents a wonderful contrast to the preceding, 

 having thirty-seven genera with 330 species. 



Of the genus Mns alone there are about one hundred 

 species, all natives of the Old World. This family is sub- 

 divided into ten sub-families. The MICE and R.ATS, Hy- 

 dromvs or Water Rat, Gerbillas or Jumping Mice, 

 Hamster, Meadow Mice, MUSK Rat, and many quite 

 unfamiliar forms represent the sub-families respectively. 



The true mice and rats are all found in parts of the Old 

 World, but are not natives of America. The genus Hes- 



