168 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 
uniting the pterygoids with inner edge of glenoid fossae. Between 
these plates and the audita 1 bullae the median surface of the skull 
is occupied by a noticeable depression about as large as palate and 
divided by cross ridges into five secondary depressions, the two pos- 
terior of which represent the basisphenoid pits. Palatal branches of 
premaxillaries and the two father large palatal foramina (each of 
which is encroached on by a posterior median spine) raised above 
level of palate, at the front of which is a secondary foramen, trans- 
versely elliptical in outline, extending from incisors to level of middle 
of anterior premolars. Audital bullae small but rather high and 
narrow, covering less than half surface of cochleae, their greatest 
diameter much less than distance between cochleae. Ear and nose- 
leaf moderately large, essentially as in Artibeus. Second finger 
strongly bowed outward, about two-thirds as long as metacarpal of 
third. No external tail. Calcar and interfemoral membrane mod- 
erately developed. 
Species examined. — Pygoderma bilabiatum Wagner and P. micro- 
don Peters. 
Remarks— The members of this genus are at once recognizable by 
the remarkably shortened and deepened cuboidal rostrum, a character 
not closely approached by any other known bats. Aside from the 
form of the rostrum, the skull is not unlike that of Centurio , Sphoero- 
nycteris , and Ametrida , with which it agrees in the strongly diverg- 
ing hamulars, and the widening of the floor of the braincase between 
palate and audital bullae, a peculiarity the first stages of which are 
seen in PhyZlops and to a less degree in Ardops , Ariteus , and Steno- 
derma. The teeth also show a general resemblance to those of Cen- 
turio and its allies, though the distortion of the tooth rows as a whole 
is in the opposite direction. Externally the animals more closely re- 
semble the true Stenodermine genera. 
Genus CENTURIO Gray. 
1842. Centurio Gray, Ann, and Mag. Nat. Hist., X, p. 259. 
1861. Trichocoryes IX. Allen, Proc. Acad. Nat. Sei. Philadelphia, p. 359. 
Snbgenns cf Centurio (mcmurtrU^ adult male senex ). 
1866. Triclwcorytes Gray, Proc. Zcol. Soc. London, p. 118 (genus). 
1878. Centurio Doeson, Catal. Chiropt. Brit. Mus., p. 542. 
1897. Trichocoryctes Trouessart, Catalogus Mammalimn, p. 164. 
1901. Centurio Rehn, Proc. Acad. Nat. Sci. Philadelphia, p. 297, June 8, 
1901. 
Type-species. — Centurio senex Gray. 
Geographic distribution. — Central America and southern Mexico. 
The supposed Cuban record is erroneous.® 
Number of forms. — Only one species is now recognized. 
a See Alston, Biol. Cent.-Amer. Mamm., 1879, p. 51 
