134 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 



ized by the very large though simple ana separate ears (the middle 

 of conch extends to nostril when laid forward) ; tail barely percep- 

 tible in base of very wide interfemoral membrane; lips and chin 

 nearly smooth ; fur unusually long and soft. 



Species examined. — C hrotopterus auritus (Peters). 



Remarks. — Though currently regarded as a subgenus of Vampyrus, 

 this group is sufficiently well characterized to be recognized as a dis- 

 tinct genus. As pointed out by Dobson, it is in many respects inter- 

 mediate between Vampyrus and the more ordinary members of the 

 subfamily. The structure of its teeth also places it in an intermedi- 

 ate position, though nearer the more normal genera than to Vam- 

 pyrus. 



Genus VAMPYRUS Leach. 



1821. Vampyrwt Leach, Trans. Linn. Soc. London, XIII, p. 79. 

 1878. Vaintujrux Dobson, Catal. Chiropt. Brit. Mus., p. 460. 



Type-Species. — Vespertilio spectrum Linna?us. 

 Geographic distribution. — Tropical America north to southern 

 Mexico ; Greater Antilles. 



Number of forms. — Only the type species is recognized. 

 Characters. — Dental formula (Plates I, II, fig. 3) : 



-2 3. 1. --34567 . 2-2 1-1 2-2 3 - 3 



1 2 -. 1. - 2 3 4 5 6 7 * 2 - 2' °1 - 1' pm 3 - 3' m 3 - 3 



Middle upper incisors low and wide, their cutting edges strongly 

 oblique, but entire, and almost in contact with canines laterally; 

 outer incisors pushed slightly forward out of tooth row, barely rising 

 to level of cingulum of canine. Canines relatively larger than in 

 any other genus of Phyllostomidas, flattened in front, the moder- 

 ately develojDed cingulum forming a low but distinct postero-internal 

 cusp. Anterior premolar (pm s ) with crown longer than wide, the 

 height of its somewhat trenchant cusp barely equal to length of 

 crown. Posterior premolar (pm 4 ) peculiar in the very slight indi- 

 cation of the postero-external thickening. Upper molars with the 

 same peculiarities as in Chrotoptervs, but much exaggerated; dis- 

 proportion between height of protocone and that of outer cusps 

 very great, owing less to suppression of forming than to unusual 

 elongation of latter; paracone and metacone so high that the outer 

 side of the teeth presents a conspicuous oblique surface, about half 

 of which is limited above by the sharply trenchant edge of the 

 fourth commissure, which has practically no posterior thickening 

 to represent metastyle. The three main cusps are so near together 

 that the triangle indicated by their points is scarcely more than 

 one-fourth the area of base of crown." Parastyle and mesostyle 



a In Chratopterus this triangle is about one-third of the crown area, while in 

 Phyllostomus it is between one-third and one-half. 



