THE FAMILIES AND GENERA OF BATS. 
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Phyllostomus , but ear longer than head, and front and sides of lips 
and chin thickly beset with small cylindrical warts, most numerous 
anteriorly. Tail much shorter than femur, appearing on upper sur- 
face of broad interfemoral membrane. 
Species examined. — Trachops cirrhosus (Spix). 
Remarks . — This genus is at once recognizable by the wart-stud- 
ded lips and the peculiar position of the small lower premolar. 
Genus CHROTOPTERUS Peters. 
1865. Chrotopterus Peters, Monatsber. k. preuss. Akad. Wissensch., Berlin, 
p. 505 (genus). 
1878. Chrotopterus Dobson, Catal. Chiropt. Brit. Mus., p. 469 (subgenus of 
Vampyrus). 
1900. Chrotopterus Allen Bull. Amer. Mus. Nat. Hist., XIII, p. 91, May 12, 
1900 (genus). 
T ype-species. — V ampyrus auritus Peters. 
Geographic distribution . — Tropical America, north to southern 
Mexico. 
Number of forms .— The type is the only species known. 
Characters . — Dental formula : 
-2 3.1. --34567.2-2 1 -1 2-2 3-3 on 
1 - 1. - 2 3 4 5 6 7 4 1-1’ c 1 - 1’ pm 3 - 3 ’ m 3 - 
Maxillary teeth essentially like those of Phyllostomus , except that 
the inner incisors are lower and less projecting, the canine is less 
distinctly grooved on front surface, the anterior premolar ( pm 3 ) 
is small, crowded outward from the toothrow, and so low that its 
short cusp barely exceeds cingulum of canine; molars with main 
cusps large and well developed, but with protocone lower in pro- 
portion to other cusps, and with paracone and metacone nearer 
each other than in the normal arrangement, and mesostyle, together 
with its commissures, notably reduced, so that the W pattern is dis- 
torted by the lengthening of the posterior limb and the shortening of the 
two median limbs. Mandibular incisors and canines as in Phyllosto- 
mus , though the canines more closely approach each other. Anterior 
premolar {pm 2 ) with the cusp broad and low, more resembling an 
angular- cutting edge than a true cusp; middle premolar {pm 3 ) mi- 
nute, crowded completely from toothrow on inner side as in Trachops , 
so that pm 2 and pm 4 are in contact. Lower molars with the cusps 
essentially unmodified, except that the hypoconid and entoconid 
are relatively lower than in Phyllostomus and the paraconid and 
metaconid of m 1 are nearer to the protoconid and less distinct from it. 
Skull essentially as in Phyllostomus , but less angular; rostrum and 
interorbital region subcylindrical ; paroccipital expansion small but 
distinct; audital bulla small, covering less than half cochlea, its 
diameter nearly twice height at inner edge. Externally character- 
