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 
Vespertilionide, 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 
