Order CHIROPTERA. 



Volant mammals, having their fore limbs specially modified for 

 flight. The forearm consists of a rudimentary ulna, a long curved 

 radius, and a carpus of six bones supporting a thumb and four 

 greatly elongated fingers, between which, the sides of the body, 

 and the hinder extremities a thin expansion of the integument 

 (the wing-membrane) is spread out. The knee is directed back- 

 wards, owing to the rotation of the hind limb outward by the 

 wing-membrane ; a peculiar elongated cartilaginous process (the 

 calcaneiim), rarely rudimentary or absent, arising from the inner 

 side of the ankle-joint, is directed inwards and supports part of 



Fig. 72. Skeleton and Volar Membranes of the Noctule ( Vesperugo noctula), 

 half nat. size. (Flower, Art. Mammalia, ' Encyclopaedia Britannica.') 



c., clavicle; h., humerus ; r., radius ; u., ulna (rudimentary) ; d.', first digit or 

 pollex ; d. z , d. 3 , d.*, d. s , other digits supporting w.m., the wing-membrane ; 

 m., m., metacarpal bones ; ph. 1 , ph. 2 , ph.*, first, second, and third phalanx of 

 third digit; am., antebrachial membrane; /..femur; t., tibia ; / ..fibula 

 (rudimentary); c., calcaneum or calcar supporting i.m., the mtertemoral 

 membrane; pc.l. s post-calcaneal lobe. 



the posterior margin of an accessory membrane of flight, extending 

 from the tail or posterior extremity of the body to the hinder 

 limbs (the interfemoral membrane). The penis is pendent, the 



