ORDER CHEIROPTERA ; GENERAL CHARACTERS. 185 



of their teeth and digestive system, which is in accordance with 

 their particular kind of food. Their molars are beset with 

 pointed tubercles, adapted to crush the hard envelopes of Insects; 

 and their canines are not unfrequently of large size, as shown 



in the accompanying 

 figure of the Head of 

 Vampyrus spectrum. 

 The intestinal canal is 

 short, and is evidently 

 adapted to the diges- 

 tion of animal food ; 

 in the Great Bat of 

 our own country it is 

 only twice the length 

 of the body ; whilst in 

 the true Yampyres of 

 South America, which 

 chiefly live on the 

 blood of other animals, 

 it proceeds from the 

 mouth to its opposite 

 termination nearly in 

 a straight line. The 

 Bats of this division 

 are arranged under 

 four families : (I.) 

 RHINOLOPHID.K, in 



FIG. 87. HEAD AND SKULL OF VAMPYRUS SPECTRUM. ,. , ,, i 



which the nose-leaf is 



of complicated structure, and formed of membranous folds ; the 

 first or fore-finger has but one joint ; and the wings are large 

 and broad. (II.) PHYLLOSTOMID^, which have but a simple 

 and fleshy appendage to the nose, and a fore-finger of two joints. 

 (III.) VESPERTILIONID.E, which are altogether destitute of nose- 

 leaf, but have broad and large wings, and a prolonged tail, but 

 with only a single joint in the fore-finger. (IV.) NOCTILIONID^, 

 which are also destitute of nose-leaf, but have long narrow 

 wings, and a short thick tail, with two joints in the fore-finger. 



