THE FAMILIES AND GENERA OF BATS. 117 



spinous process, capitellum distinctly out of line with shaft; second 

 manal digit with well-developed matacarpal and small, distinct 

 phalanx; third finger with three completely bony phalanges; shoul- 

 der girdle normal, the seventh cervical vertebra free from anterior 

 dorsal; foot normal; fibula present, cartilaginous above, this carti- 

 laginous portion usually beginning opposite a noticeable process on 

 tibia considerably below proximal extremity; pelvis normal, except 

 that elements of sacrum early disappear, the posterior half forming 

 a narrow, transversely flattened urostyle, and ischia are closely 

 approximated posteriorly, occasionally fusing with extremity of 

 urostyle; skull without postorbital processes; premaxillaries com- 

 plete, fused with each other and with maxillaries, their palatal bran- 

 ches isolating two lateral palatal foramina; teeth highly diverse in 

 structure, those of different groups representing stages of develop- 

 ment from the normal insectivorous type to the practical equivalent 

 of the Pteropine form ; tragus present, variously thickened and 

 notched; a simple nose leaf generally present, through occasionally 

 rudimentary or absent. 



Remarks. — The members of the family Phyllostomidse are recog- 

 nizable by the presence of three completely bony phalanges in the 

 third finger, the entire premaxillary, the slender, incomplete fibula, 

 and the well-developed molar teeth. Though some of the genera lack 

 cutaneous nasal outgrowths, those which have nose-leaves are the only 

 American leaf-nosed bats, and these structures are never as highly 

 developed as in some of the Old World families. This is the first 

 family in which the humerus has a definite double articulation with 

 scapula. In most of the genera the trochiter is applied to the scapula 

 by an articular surface nearly one-third as large as glenoid fossa. 

 This surface is, however, much smaller in the only skeleton of Chro- 

 topterus that I have seen (Cat. No. 113852, U.S.N.M.), while in the 

 three genera of Chilonyterinse it is absent. The humerus in this sub- 

 family is also peculiar in its narrow, somewhat oblique head, above 

 the level of which the tubercles scarcely rise. In the other groups 

 the head is nearly round, and is very distinctly exceeded in height 

 by the tubercles. 



History. — Though originally associated with the Vespertilionidse, 

 this family was recognized as a distinct group under the name 

 Vampiridse by Bonaparte as early as 1838. As such it has been 

 almost universally regarded by subsequent authors, whose ideas are 

 sufficiently presented in the synonymy. 



Principal subdivisions. — The members of the family show such 

 marked diversity in structure, principally of the teeth, that it seems 

 necessary to divide them into seven subfamilies. 



