CHIROPTERA 643 
frugivorous Pteropudide, the vertebre, from the third cervical back- 
wards, are devoid of neural spines. From the first dorsal to the 
last lumbar vertebra the spinal column forms a single curve back- 
wards, which is most pronounced in the lumbar region. The centra 
of the vertebre are but slightly movable upon each other, and in 
old individuals appear to become partially ankylosed together. 
The caudal vertebre are simple cylindrical bones without processes ; 
their number and length being extremely variable even in closely 
allied species ; and the anterior caudals are generally united to the 
Fic. 297,—Skeleton and flying-membranes of the Noctule Bat (Vesperugo noctula). x }. 
c, Clavicle; h, humerus; 7, radius; vu, ulna (rudimentary); d@}, pollex; ¢@°, d3, d4, @5, other 
digits of the manus supporting wm, the wing-membrane ; a, m, metacarpal bones ; phi, first 
phalanx ; ph?, second phalanx; pk, third phalanx; am, antebrachial membrane; jf, femur; 
t, tibia; fb, fibula (rudimentary) ; c, calear supporting im, the interfemoral membrane; pel, post- 
calcaneal lobe. 
ischial tuberosities. The relative development of the caudal 
vertebre is, indeed, intimately correlated to the habits of the 
animals ; the long tail in the insectivorous forms supporting and 
controlling the position of the large interfemoral membrane, which 
appears not only to aid their rapid motions when in pursuit of their 
prey by acting as a rudder, but also to assist in the capture and 
retention of the larger insects. In the frugivorous types, on the 
other hand, this is not required, and the tail is accordingly rudi- 
mentary or absent. In all Bats the presternum has a prominent 
keel for the attachment of the great pectoral muscles. In most 
