4 VESPERTILIONIDJE. 



every part ; it extends not only between the elongated 

 fingers, but from the last finger to the posterior ex- 

 tremity, and in the greater number of the known 

 species, from, this to the tail. That portion which is 

 situated between the hinder legs, and in which the tail 

 is included, is termed the interfemoral membrane, and 

 is generally, but not always, present in the insectivorous 

 species, some of the Phyllostomidce, or Leaf-nosed Bats 

 of the New World, forming an exception to this rule. 



Of the fingers of the anterior extremity, the thumb is 

 the only one which is left free ; it is of moderate length, 

 and furnished with a hooked nail. The hinder toes are 

 short, of nearly equal length, and are chiefly used as 

 suspending organs, the Bats hanging by them, from the 

 trees or walls on which they rest, with the head down- 

 wards.* 



The flying membrane is not the only part which indi- 

 cates a tendency to an extraordinary development of the 

 cutaneous system. The ears and the nose exhibit in 

 many cases a curious conformation, consisting of the 

 great expansion of the former, and some remarkable 

 appendages to the latter. The ears are, in all the British 

 Bats, of considerable extent ; and the tragus is of large 

 size in those in which the nasal appendages just alluded 

 to do not exist : in the Long-eared Bat, the ear is nearly 

 as large as the body, and the tragus very long ; but in 

 the Rhinolophus, or Horse-shoe Bat, though the ears are 

 large, the tragus is not perceptible ; and there are certain 

 very curious foliaceous appendages to the nose, which 

 will be described hereafter. 



Admirably as this extension of the anterior extre- 



* The figure at page 11 is a representation of the Long-eared Bat, Plecotus 

 auritus, in this position ; the long ears being folded under the arms, and 

 almost wholly concealed by them, whilst the tragus is exposed and pendulous. 



