CHAPTER XL 



Bats, — concluded. 



The Free-Tailed Ixsectivokous Bats. 



The chief ilistinctive features of this group are that, as a rule, the tail (when 

 present) either penetrates the membrane between the legs, so that its extreinitv 

 appears on the upper surface, or it is pi'odueed considerably beyond the hinder 

 margin ; secondly, that the innermost (frequently the only) pair of upper incisor 

 teeth are generally of large size, and placed very close together; and, thirdly, 

 that except in two genera, each represented bj' a single species, the first joint of 

 the third or middle finger of the wing is, when at rest, folded back upon the 

 upper surface of its supporting metacarpal, instead of being extended forwards in 

 the same line, as in the species we have hitherto described. Not a single repre- 

 sentative of this large assemblage of bats is found in the British Isles, and, 

 indeed, only one species occurs within the limits of the European area. They are 

 mainly characteristic of ti-opical and subtropical regions ; but whereas the fii-st of 

 the two families into which they are divided ranges o\er both hemispheres, the 

 second is strictly confined to the central and southern portions of the Western. 

 The number of genera — to say nothing of species — included in the two families 

 is very large, and as many of them are distinguished from one another by 

 comparatively trivial characteristics, we shall notice oidy a few typical forms, of 

 special interest either from pecuKarities of structure or of habits. 



The Smooth-Nosed Feee-Tailed Bats. 

 Family EilBALLONuniD.-E. 



The first family of the group occupies a position precisely similar to that held 

 hx the Typical Bats (Vespertilionidw) in the other branch of the insect-eaters 

 treated in the preceding section. In addition to the peculiar mode of folding the 

 tliird finger of the wing, and the characters of the tail already alluded to, they 

 are distinguished by the circumstance that there are but two bony joints in this 

 third finger, as also by tlie absence of any distinct nose-leaf. As a rule, they 

 have a small tragus in the ear, and only a single pair of upper incisor teeth, which 

 incline towards one another. Moreover, the extremity of the snout is obliquely 

 truncated from above downwards, so as to cause the nostrils to project more 

 or less in front of the tip of the lower jaw. The family is widely distributed 

 over the wai-mer regions of both the Eastern and Western Hemispheres, and 

 includes one of the two species which are the only representatives of the entire 



VOL. L — 19 



