142 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 



cave on inner side, the hamulars in contact with audital bullae. 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, G. mexicana, Tschudi, and 0. minor Peters. 



Genus HYLONYCTERIS Thomas. 



1903. HyJoiujcteris Thomas Ann. and Mag. Nat. Hist., 7th sei\, XI, p. 286. 

 March, 1903. 



Type-species. — Iiylonycteris underwoodi Thomas. 



Geographic distribution. — Costa Rica. 



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



Characters. — Closely resembling Cheer onycteris 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. — Iiylonycteris underwoodi Thomas. 



Remarks. — Iiylonycteris, though very closely related to Chosronyc- 

 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. Ischnoglossa Saussure, Rev. et Mag. de Zool., 2" ser., XII, p. 491. 



November, 1860. Not of Kraatz, 1856. 

 1878. Ischnoglossa Dobson, Catal. Chiropt Brit. Mus., p. 505. 

 1891. Leptonycteris Lydekkek, in Flower and Lydekker, Mammals living 



and extinct, p. 071. 

 1898. Leptonycteris II. Allen, Trans. Amer. Philos. Soe., 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 : 



-23. 1. --345 6- .2-2 1-1 2-2 2-2 



r^=Tl7^~3T5~6" l 2^2' ° 1^1' P" 1 3^3' m J^ = 3 °- 



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 



