56 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 



Species examined. — Pterocyon buttikoferi ( Jentink) P dupreanus 

 (Pollen) and P. Stramineus (Geoffroy). 



Remarks. — This genus is distinguishable from all other groups of 

 Chiroptera by the structure of the audital bullae, and from its nearest 

 ally, Rousettus, by the entire-edged lower incisors as well. 



The type specimen of Leiponyx buttikoferi, which I have examined 

 in company with Doctor Jentink, appears to be unquestionably a 

 Pterocyon in which the claw of the index finger is lacking. The 

 individual is so old that the crowns of the molars are completely worn 

 away, a fact that may have some bearing on the absence of the claws. 

 While the form of the molars can not be determined, the incisors, 

 canines, and anterior premolars agree perfectly with those of 

 Pterocyon, as do also the general aspect of the skull, the peculiar 

 structure of the audital bullae, and, with the one exception already 

 noted, the details of external form. 



Genus PTEROPUS Brisson. 



1762. Pteropus Beisson, Regn. Anim. in Classes IX distrib., 2 ed., p. 13 

 ( vampyrus ) . 



1799. Spectrum Lacepede, Tabl. des Div. Sousdiv.' Orders et Genres, des 

 Mammif., p. 15 {vampyrus). 



1866. Eunycteris Gray, Proc. Zool. Soc. London, p. 64 (phaiops). 



1870. Pselaphon Gbay, Catal. Monkeys, Lemurs and Fruit-eating Bats Brit. 

 Mus., p. 110 (ursirnis=pselaphon). 



1878. Pteropus Doeson, Catal. Chiropt. Brit. Mus., p. 15 (part, included 

 Acerodon and Styloctenium) . 



1899. Pteropus Matschie, Flederrn. des Berliner Mus. fiir Naturk., p: 5 

 (part, included Pteralopex and Acerodon). 



1899. Sericonycteris Matschie, Flederm. des Berliner Mus. fiir Naturk;, p. 30 

 (subgenus of Pteropus containing the species rubricollis, temmincki, 

 jpetersi,personatus, capistratus, molossinus, ivoodfordi). 



1899. Eunycteris Matschie, Flederm. des Berliner Mus. fiir Xaturk., p. 11 

 (subgenus of Pteropus containing the species melanopogon, papua- 

 nus, degener, neohioernicus) . 



1899. Spectrum, Matschie, Flederm. des Berliner Mus. fiir Xaturk., p. 19 (sub- 

 genus of Pteropus containing the species poliocephalus, leucopterus, 

 pselaphon, vetulus, vampyrus, anetianus, rayueri, samoensis, dasy- 

 mallus, loochooensis, fonnosus, rodricenxix, lotiihocensis, brunneus. 

 scapulatus, Hvingstoni, macrotis, epularls, assamensis, hypomela- 

 nus, mariannus. 



Type-species. — V espertilio vampyrus Linnseus. 



Geographic distribution. — From the Comoro Islands, Madagascar, 

 and India, to Tasmania, Samoa, the Ladrones, and southern Japan 

 (Kiusiu). 



a Specimens with one or both claws very imperfectly developed, or perhaps 

 reduced by disease or injury, have been observed in Pteropus capistratus (No. 

 122124, U.S.N.M-.), P. hypomelanvs (No. 105440), P. modiglianii (No. 140992), 

 P. poliocephalus (No. 13594), and Acerodon sp. (No. 105454). 



