MOLES, SHREWS AND BATS 201 



Little is known of the habits of either, and they 

 are chiefly notable because closely related to 

 certain insectivores of Madagascar, the tenrecs, 

 indicating descent from a common and ex- 

 tremely primitive source, as the only explana- 

 tion of their now living in two so widely sepa- 

 rated regions. 



American bats. These insect-eating mam- 

 mals of the air constitute a distinct group 

 (Order Chiroptera), characterized by the pos- 

 session of leathery wings, and other features 

 which separate them from the terrestrial in- 

 sectivores. North America has about twenty 

 species, nearly all of the world-wide family 

 Vespertilionidce, in which the nostrils are 

 without those membranous appendages called 

 a nose-leaf, and the ears are of moderate 

 size and shape. On our southwestern border, 

 however, occurs a true nose-leafed, fruit-eat- 

 ing bat or two, representing families numerous 

 in Mexico, Central America and the West In- 

 dies, to one of which belongs the dreaded 

 vampire, the blood-sucker of equatorial South 

 America. Most of the North American bats 

 are confined to the warm South, but half a 



