538 



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



42. Pachyotus altilis (G. M. Allen). 



The silky fur of this brown bat is not very long, rather light above and 

 decidedly pale beneath. Its flight membranes are of a much darker brown; 

 the wings spread about 11 inches (279 mm.), while the length inclusive of 

 tail is 4.64 inches (118 mm.). 



Known hitherto from the Blue Nile, it ranges into the Uele district, 

 probably to the edge of the forest. Only two specimens, however, were 

 taken by us in March at Faradje, where they were shot as they flew about 

 over the bank of the river at dusk. One of them had two large embryos 

 in its uterus. In the male the scrotal sacs occupy a curious position, close 

 together but posterior to the anus. 



43. Pachyotus nigrita nux Thomas, 



This is the largest vespertilionid in our collection; it attains a total length 

 of 4.8 inches (122 -mm.). The wings, with a spread of 13.8 inches (350 mm.), 

 are as black as the rounded ears and the muzzle. The rather smooth fur 

 is russet above and ochraceous tawny on the lower side. 



The stomach contents showed minute remains of insects, and both 

 specimens had each a large foetus (March). Natives, who were occupied in 

 felling trees to make the necessary clearing for a plantation, claimed to have 

 taken them in a hollow trunk from which many others escaped. This 

 information is undoubtedly correct, inasmuch as these bats show a rather 

 large pad beneath the thumb indicative of climbing upon hard or rough 

 surfaces. 



44. Glauconycteris papilio (Thomas). 



The "butterfly bat" is the prettiest bat we met with in the Congo. Of 

 medium size, it measures 4.05 inches (103 mm.) in length, and its wings 

 extend 12 inches (305 mm.). The dry skins of collections can hardly give 

 an idea of the delicate and charming pattern of their wings. Indeed when 

 alive the curious dark veining is admirably set off by the orange hues of 

 the dull velvety background of wing and interfemoral membranes. The 

 tiny rufous or brown body, much lighter below, and the blunt head attract 

 but little attention. The tail takes up about half of the total length. 

 The females average somewhat larger than the males. 



Out of ten females collected in March, two had one foetus each, but 

 another had two young ready to be born. Their breeding season therefore 

 is perhaps restricted to March and April. The bats and their young could 

 then take refuge in the bushes and low trees newly burst into leaf after the 



