NYCTINOMUS TENUIS, 



The Nyctinomi, as their name denotes, feed at night. During my residence 

 on the hills of Prowoto, which have already several times been mentioned in these 

 Researches, their pursuit afforded me an occasional amusement. Although they are 

 also found in other parts of Java, they are peculiarly abundant on these hiUs, which 

 are covered with a luxuriant vegetation, and afford a plentiful supply of their 

 favourite food. They appeared after sunset, while the light was still sufficient for the 

 purpose of distinguishing objects clearly. Observing them almost uniformly, and 

 in quick succession to direct their flight along the hedge, which surrounded a village 

 in which I had my abode, I watched them in this situation, and readily caught 

 them with a large net, which was used in the pursuit of Lepidopterous Insects. 

 By this means I obtained them in great numbers, and selected those that were 

 required for my collections. 



I shall conclude this article with a few concise comparative remarks on the 

 various species of Nyctinomus hitherto discovered, and with an enumeration of their 

 specific characters. The Nyctinomus tenuis exhibits very strikingly the characters 

 which afford to the Nyctinomi generally a very peculiar physiognomy ; but the 

 narrowness of its wings, and the slenderness of its tail, distinguish it clearly from 

 the other species. For a comparison with the Nyctinomus Egyptiacus, the copious 

 description of M. Geoffroy, accompanied by an accurate and beautiful figure, in the 

 " Description de I'Egypte," afford the most ample materials. From these it appears, 

 that the ears in the Egyptian species spread more in a lateral direction, and 

 that the interfemoral membrane is deprived of muscular fibres. It has likewise 

 a very different colour, being reddish brown above, and brown underneath. Further, 

 I have not observed in M. Geoffroy 's figure, so distinctly as occurs in our species, 

 the short stiff bristles which are scattered profusely on the sides of the face, and 

 the dots in the membrane of the wings, on each side of the body. By possessing 

 these, the Nyctinomus tenuis exhibits a great resemblance to Commerson's species, 

 the Nyctinome de Port-Louis ; but the latter is considerably smaller ; the membrane 

 of the body is described as " nuda ad sternum " (Hermanni Obs. Zool. p. 19,) and 

 the interfemoral membrane envelopes two-thirds of the tail. The Nyctinomus 

 of Bengal agrees with our species in possessing the transverse muscular fibres of 

 the interfemoral membrane ; but it is distinguished by a more robust habit, by a 

 thick, round, fleshy tail, and by a very short thumb. 



Having above mentioned a second species of Nyctinomus from Java, for which 

 I have proposed the name of dilatatus, I shall now add the distinguishing characters, 

 and subjoin those of the other species in succession. 



