270 the geography of mammals 



Deductions 



1. The Order of Chiroptera, or Bats, contains about 530 

 known species which are divided into ninety-five genera 

 and six families. 



2. They are found in every part of the world except 

 within the Arctic and Antarctic Circles, and even in many 

 islands where no other mammals occur. 



3. The Fruit-bats {Pteropodidte) are met with only in 

 the Old World, and mainly within the tropics. 



4 The Vampires (Phyllostomatidie) are entirely re- 

 stricted to the Neotropical Region, except two or three 

 species (out of eighty) which have passed over the boun- 

 daries into the Nearctic Region. 



5. Two forms of the Vampires {Desmodus and D'qihylla), 

 having their dentition and digestive organs specially 

 modified for that purpose, feed on the blood of living 

 animals. 



Section IV.— Distribution of Rodents 



Rodents are by far the most numerous of all the Orders 

 of Mammals, comprising, according to a moderate calcula- 

 tion, nearly 1400 species which are arranged in 159 genera 

 belonging to twenty-one distinct families. They are also 

 among the most universally distributed of terrestrial 

 mammals, being found in all latitudes high and low, and 

 abundant in every part of the earth except Australia, 

 where they are feebly represented by a few genera and 

 species. The Rodents, especially the Mice (Muridtv), to 

 which family rather more than half their number belong, 

 are still imperfectly known ; their arrangement and classi- 



