530 



Bulletin American Museum of Natural History. [Vol. XXXVII r 



were observed. One of them, more than half-grown, was still carried by 

 its mother, as it happens in nearly all bats. 



Their flight is rather unsteady, nearly fluttering, as they zigzag between 

 the frayed-out leaves of the bananas, but rarely do they make abrupt turns. 

 They seem to avoid the open places of villages where other bats are most 

 conspicuous. 



The distribution of P. nanus includes nearly all of the Ethiopian and 

 Malagasy regions. Thus it is among the most widely distributed of African 

 bats, and naturally we found it in both the open and the forested regions. 



Sometimes they hide in the thatch of the houses or pursue tiny insects 

 around a lighted lamp; but we found them, together with another form 

 of the orange-rufous Myotis bocagii, chiefly in the native gardens. They 

 may take refuge underneath the hanging dry leaves of plantains or wherever 

 they find suitable cover. Their favorite hiding-places are the nearly full- 

 grown bunches of green bananas. They crawl into the darker spaces 

 between the fruits, one or two together. Here they hang in safe and com- 

 fortably cool surroundings huddled up in a tiny ball from which the small 

 ears stand out laterally, or cling to the bases of the fruit with thumbs and 

 feet. No wonder that they show special adaptations. The thumb has a 

 large wrinkled callosity and tiny furrows on its under side that by contrac- 

 tion may act as a sucker. Their feet also show similarly wrinkled soles 

 and toes, and thus appear well fitted for crawling and hanging on such 

 smooth surfaces as those of plantains and bananas. 



Naturally such a shelter is available only for a short period, hardly 

 exceeding a month, as the plantains become ripe enough to cut down for 

 consumption. Therefore these pipistrelles have no stable household like 

 most of the molossids, which live for decades in the same hollow tree and 

 perhaps for ages in the same rocky cleft, but on the contrary have to keep 

 on the move. From time to time negroes in these regions abandon their 

 villages and plantations, and the pipistrelles in all probability follow. Va- 

 grancy is thus forced upon them and their ubiquitous appearance seems to be 

 merely a consequence of the peculiar conditions offered by the cultivation 

 of plantains and bananas. Though we found them most common in regions 

 where such plantations are numerous, we have no doubt they can adjust 

 their habits to other conditions. 



They have hardly any voice, but taken alive and held in the hand these 

 tiny bats snap their mouths open amazingly wide, to an angle of 120°, and 

 what is still more astonishing they keep it in that position apparently with- 

 out any effort. A comparison with most living carnivora shows that the 

 latter cannot open their mouth, hard as they may try, even to a right angle, 

 only far enough to bite at their victims or to crush bones. Years ago, the 



