THE FAMILIES AND GENERA OP BATS. 91 



Number of forms. — The type species is the only member of the 

 genus now known. 



Characters. — Like Peropteryx, but rostrum so little inflated anteri- 

 orly that its dorsal profile slopes conspicuously forward toward line 

 of tooth row. Ears joined across forehead by a band of membrane 

 3 mm. high. In the only known species the wings are white from 

 level of elbow outward (five specimens examined). 



Species examined. — Peronymus leucopterus (Peters). 



Remarks. — The peculiar form of the rostrum, together with the con- 

 nected ears, seem enough to give Peronymus generic rank. Though 

 in exactly the same position, the wing sac is better developed in the 

 female of Peronymus than in that of Peropteryx. 



Genus CENTRONYCTERIS Gray. 



1838. Oentronycteris Gray, Mag. Zool. and Bot, II, p. 499 (subgenus of 

 Proboscidea) . 



1867. Oentronycteris Peters, Monatsber. k. preuss. Akad. Wissensch., Ber- 

 lin, p. 478 (genus). 



1878. Oentronycteris Dobson, Oatal. Chiropt. Brit Mus., p. 371 (subgenus 

 of Saccopteryx) . 



Type-species. — Vespertilio calcarata Wied=F. maximiliani Fischer 

 (Saccopteryx wiedi Palmer) . 



Geographic distribution. — Brazil and Peru. 



Number of forms. — The type is the only known species. 



Characters. — Similar to Saccopteryx, but whole animal, including 

 skull, more slender. Lower edge of orbit so little expanded that 

 tooth row is distinctly visible from above. Wing sac not known (all 

 the specimens thus far taken have been females) , but probably situ- 

 ated near edge of antebrachial membrane close to shoulder. 



Species examined. — Centronycteris maximiliani (Fischer). 



Genus MYROPTERYX Miller. 



1906. Myropteryx Miller, Proc. Biol. Soc. Washington, XIX, p. 59, May 1, 

 1906. 



Type-species. — Myropteryx pullus Miller. 



Geographic distribution. — Brazil and Dutch Guiana. 



Number of forms. — The type is the only member of the genus yet 

 known. 



Characters. — Externally most nearly resembling Peropteryx, with 

 which it agrees in position of wing sacs, but with broader head and 

 more widely separated ears. Skull essentially like that of Saccop- 

 teryx, but with shorter; relatively deeper rostrum. Teeth differing 

 from those of all the previously known sac-winged genera in the 

 absence of hypocone in first and second upper molar, and in the 

 minute, early deciduous upper incisor. 



Species examined. — Myropteryx pullus Miller. 



