552 CHORDATA. 
The fox-bat may have an expanse of five feet across the 
wings. The head is not unlike that of a small fox, with a 
sharp intelligent look about the eyes. The external ears are 
large and the sense of hearing is acute. The body is 
covered with fine thick hair which is woolly round the 
neck. The whole appearance of the animal is totally unlike 
that of any other mammals outside the order, owing to the 
presence of an enormous pair of membranous wings (though 
Fig. 380.—THE FEcToRAL GIRDLE AND Fore-LimB oF PTEROPUS. 
(Ad nat.) 
Clavicle. 
Scapula. 
Humerus. Ulna. 
an approximation to this condition is found in the colugo). 
The wing, as is clearly seen in the skeleton, is formed by the 
fore-limb, upon which is stretched the membrane. The con- 
cavity of the elbow is filled with a small antebrachial mem- 
brane. The hind-limbs are very small and armed with claws. 
The patagium extends from the fore-limb down to the ankles, 
being attached to the sides of the body, and a slight inter- 
femoral membrane stretches across between the hind-limbs. 
These three membranes form the patagium, consisting 
