142 BULLETIN 57 , UNITED STATES NATIONAL MUSEUM. 
cave on inner side, the hamulars in contact with audital bullse. Tail 
well developed, about half as long as femur, extending less than half 
way to edge of very wide interfemoral membrane. Calcar present, 
distinct though weak. 
Species examined. — Cheer onycteris godmani Thomas, C. intermedia 
Allen and Chapman, C. mexicana , Tschudi, and C . minor Peters. 
Genus HYLONYCTERIS Thomas. 
1903. Hylonycteris Thomas Ann. and Mag. Nat. Hist., 7th ser., XI, p. 286. 
March, 1903. 
T ype-species. — Hylonycteris underwoodi Thomas. 
Geographic distribution. — Costa Rica. 
Number of forms. — Only the type species is known. 
Characters. — Closely resembling Choeronycteris in all respects ex- 
cept that the pterygoids are not specially modified, their inner sur- 
face being convex and the hamular processes not coming in contact 
with the audital bullae. 
Species examined. — Hylonycteris underwoodi Thomas. 
Remarks. — - Hylonycteris , though very closely related to Chceronyc- 
teris , is well characterized by the form of the pterygoids. These 
bones are perfectly normal, quite as in other members of the sub- 
family, and lack all trace of the peculiar structure which they have 
assumed in the allied genus. 
Genus LEPTONYCTERIS Lydekker. 
1860. Isclinoglossa Saussure, Rev. et Mag. de Zool., 2 e ser., XII, p. 491. 
November, 1860. Not of Kraatz, 1856. 
1878. Isclinoglossa Dobson, Catal. Chiropt. Brit, Mus., p. 505. 
1891. Leptonycteris Lydekker, in Flower and Lydekker, Mammals living 
and extinct, p. 674. 
1898. Leptonycteris H. Allen, Trans. Arner. Philos. Soc., n. s., XIX, p. 250. 
Type-species. — Ischnoglossa nivalis Saussure. 
Geographic distribution. — Mexico, Central America, and the island 
of Curacao, off the coast of Venezuela. 
Number of forms. — Two species of Leptonycteris are known. 
Characters . — Dental formula : 
-2 3 . 1 . - -3456 - , 2-2 
12 -. 1 . - 23456 - 1 2 - 2 ’ 
1-1 2-2 
1 - 1 ’ P m 3 - 3 ’ 
m 
2-2 
2-2 
= 30 . 
Upper incisors rather large, forming an almost continuous line 
between canines, or separated by median space into two pairs, the 
crowns projecting forward. Crown of inner incisor about as long 
as high, the cutting edge straight, nearly horizontal. Crown of 
outer higher than that of inner, its length about half height, the ex- 
tremity rather sharply pointed. Lower incisors well developed, with 
