CHEIROPTERA. 121 



extends between the thighs. They inhabit the tro- 

 pical and temperate parts of the whole earth. 



The insectivorous bats may be divided into two 

 principal tribes ; the first having the middle finger 

 in the membrane, with three ossified phalanges, 

 while the others, including the index, possess only 

 two ; the second, with only one ossified phalanx for 

 the index, and the other fingers two or three. 



Tribe I. Diphalangia anistiophora. Two-jointed 

 Leafless Bats. Having the index with two ossified 

 phalanges, a nose simple, destitute of a leafy appen- 

 dage. 



Genus DYSOPES, Illig. Bull Dog Bats. The 

 head thick ; muzzle broad and flat ; ears very large, 

 approximated, recumbent over the eyes, and arising 

 from the commissure of the lips; upper lip large 

 and wrinkled. Dental formula varying according 

 to age, incis. f, can. \-{, mol. T 8 o = }-f = 26. 

 But the incisors are very variable, at first f , then 

 f, later f, adult f, old . The toes are covered 

 with bristles; the hinder thumbs free, sometimes 

 opposable ; the wing membrane narrow ; tail long, 

 partly engaged in the interfemoral membrane. They 

 inhabit the tropics, and warmest parts of the earth. 



It is from this genus, Dysopes cestonii, that Pro- 

 fessor Savi formed his genus DINOPS, because his 

 specimens had the six incisors of extreme youth. 

 M. Geoffroy made his genus NYCTINOMUS from 

 young animals, which had four incisors in the lower 

 jaw ; Dr. Horsfield, his CHEIROMELES from a species 

 which had the character of an opposable thumb on 



