VESPERTILIO 127 



Pipistrelle swoop through a swarm of gnats, and have, on 

 favourable opportunities, seen the tail depressed to ' bag ' 

 the membrane, the animal's flight at same moment — or in 

 the same movement — often turning slightly upward. It 

 appeared to me that this manoeuvre could have no other 

 purpose than the capture of insects, and when I found that 

 another observer had recorded the same thing, I accepted it 

 as confirmation of my own opinion, and adopted it as fact." 

 Lastly, Mr Adams informs me that he observed the manoeuvre 

 in sunlight on 17th March 1906. 



When feeding at large, Pipistrelles, like the Noctule, 

 execute falcon - like swoops on their invisible prey, with 

 the wings evidently spread to their widest extent, so that 

 way is kept on even at the fullest depth of the plunge. On 

 other occasions an intermediate line of action may evidently 

 be taken, since I have seen a remarkable headlong descent, 

 during which one wing was for an instant curiously curved 

 so as almost to enclose the body in front. No doubt, like 

 other animals, bats are not such rigidly red-tape disciplinarians 

 as to be forced to follow a fixed sequence of movements every 

 time they catch a fly. It is probable, therefore, that their 

 plans are varied, the smaller flies being snatched up without 

 trouble, while for the capture of the larger insects the mem- 

 branes may be to a lesser or greater extent employed, or the 

 struggling victim may even be carried off to be mastered at 

 leisure in some secure retreat. 



Genus VESPERTILIO. 



1758. VESPERTILIO, Carolus Linn£eus, Systema Nattirce^ x., 31-32 ; based on Vesperftlw 

 muriftus of Linnsus (not V. miirinus of Schreber, 1775, see above, page 51). 



1820, Eptesicus, C. S. Rafinesque, Amials of Nature^ 2 ; based on Eptesicus 

 inelanops of Rafinesque = Vesperiilio fuscus of Beauvois. 



1829. Cneph^US, Jakob Kaup, System der Europaischen Thierwelt, i., 103 ; based 

 on Vespertilio serotinus of Schreber. 



1839, Vesperugo, a, Graf von Keyserling and J. H. Blasius, Wiegmann's Archiv 

 fiir Naturgeschkhte, i., 312 ; based on Vespertilio serotinus of Schreber, and eleven 

 other species. 



1839. Vesperus (sub-genus), auct. et op. cit., 313; based on the thirty-two toothed 

 species of the genus Vesperugo, e.g., serotinus of Schreber, discolor of Natterer, 

 nilssoni of Keyserling and Blasius, savii of Bonaparte, leucippe of Bonaparte, and 



