120 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 
or there is a small diastema between canine and outer incisor. 
Lower incisors of about the same relative sizes as upper, but outer 
somewhat less reduced. The crown of the inner tooth is longer 
than broad and noticeably constricted posteriorly, that of the outer 
subterete; cutting edges trifid. The incisors form a continuous row 
between canines. Upper canines strong, with concave inner surface 
and distinct anterior and posterior cutting edge arid fairly well de- 
veloped cingulum, but no secondary cusps. Cheek teeth strictly 
normal ; m 1 and m 2 , with well-developed hypocone ; m 8 with five 
cusps and three distinct commissures, its crown surface more than half 
that of m 1 , middle lower premolar (^>m 3 ) much smaller than other 
two. Lower molars with cusps normal in size and position. Skull 
with rostrum nearly as long as braincase, its sides slightly but 
distinctly inflated from orbit to nares, its dorsal surface with shallow 
longitudinal groove. Anterior portion of rostrum broad (palate 
broader anteriorly than posteriorly) ; nares subcircular, opening 
almost directly forward. Braincase subglobose, its length, breadth, 
and depth about equal. No distinct sagittal crest or ridges for muscle 
attachment. Floor of braincase slightly elevated above level of dor- 
sal wall of clioanse. Audital bullse small, covering not more than half 
of the large cochleae. Wings from sides of body, the back completely 
furred. Dermal outgrowths on chin not excessively developed. 
Species examined. — I have examined all of the known forms except 
C. personata Wagner. 
Genus PTERONOTUS Gray. 
1838. Pteronotus Gray, Mag. Zool. and Bot., II, p. 500. 
1878. Cliilonycteris Dobson, Catal. Cliiropt. Brit. Mus., p. 447 (part). 
1890. Pteronotus Allen, Bull. Amer. Mas. Nat. Hist., Ill, p. 178, December 
10, 1890 (genus). 
1901. Dermonotus Gill, Proc. Biol. Soc. Washington, XIV, p. 177, Septem- 
ber 25, 1901. 
1904. Dermonotus Rehn, Proc. Acad. Nat. Sci. Philadelphia; p. 250, March, 
1904, issued April 7, 1904. 
1905. Pteronotus Miller, Proc. Biol. Soc. Washington, XVIII, p. 223, Octo- 
ber 17, 1906. 
Type-species. — Pteronotus davyi Gray. 
Geographic distribution. — Mainland of tropical America north to 
southern Mexico; also the islands of Trinidad and Dominica, West 
Indies. 
Number of forms. — Three; two in South America and the West 
Indies, the other in Mexico. 
Characters. — Like Chilonycteris , but with the wings attached 
along middle line of back. 
