8o BRITISH MAMMALS 



Its range is confined mainly to Southern Asia and Australia, with 

 a few representatives in Madagascar and Africa. The fruit-eating 

 bats would seem to be a later development in time than some 

 of the insectivorous forms ; yet, though specialised in some 

 directions, they must have evolved from a more archaic type of 

 bat than any now existing, since they retain the original three 

 phalanges of the second finger (which is also provided with a 

 claw), the long muzzle, large eyes, simply constructed ears 

 without a tragus, and generally simple nose.^ On the other 

 hand, their molar teeth (except in one genus) are devoid of cusps, 

 are smooth, and are marked with a longitudinal groove. The 

 fruit-eating bats include the largest specimens of the order, and 

 as a rule are much larger than the insect-eating sub-order. 



The Microcheiroptera^ indeed, tend towards diminutive size. 

 Unlike the fruit-eating bats, they are almost world-wide in 

 distribution, only excepting the Arctic and Antarctic regions 

 from their range. The crowns of the molar teeth are set with 

 sharp cusps separated by transverse grooves, and not longitudinal, 

 as in the fruit-eating bats. As already pointed out, the index 

 finger never has more than two, and usually only one phalanx, 

 which may be quite rudimentary. The lower incisors are, with 

 very few exceptions, more numerous than those in the upper jaw. 

 The ears, which sometimes attain exaggerated development, 

 beyond anything met with in any other mammal, are signalised 

 by this peculiarity, that the outer and inner sides of the ear conch 

 start separately at their base, and not from a common meeting 

 point. Moreover, the tragus, or forward flap of skin (which in 

 the human species guards the entrance to the inner ear), often 

 attains an excessive and extravagant development. There is 

 nearly always something strange or eccentric about the nostrils. 

 These are marked in many species by an excrescent growth, 

 occasionally of extravagant dimensions and intricacy of pattern. 

 The fantastic ornamentation of the nose and muzzle sometimes 

 includes the lower lip. The eyes are invariably small, and in 

 some species are scarcely functional. 



1 Though the nostrils may sometimes be prolonged into tubes. 



