1917.] Allen, Lang and Chapin, Bats from the Belgian Congo. 441 



31. Pipistrellus nanus (Peters). 



Vespertilio nanus Peters, Reise nach Mossambique, I, Saugeth., p. 63, pi. xvi, 

 fig. 2. Inhambani, Mozambique, S. lat. 24°. 



Sixty-seven specimens (of which 39 are alcoholic): Stanleyville, 6 (2 

 alcoholic), Aug. 5-27, 1909; Risimu, 1 (alcoholic), Sept. 9, 1909; Ngayu, 

 4 (1 alcoholic), Dec. 14, 1909; Bafwabaka, 30 (9 alcoholic), Jan. 5-14, 

 1910; Gamangui, 1, Feb. 27, 1910; Medje, 6 (5 alcoholic), Oct. 7, 1910; 

 Niangara, 9 (1 alcoholic), Nov. 11-14, 1910; Faradje, 7 (4 alcoholic), Feb. 

 18, 1912; Yakuluku, 1 (alcoholic), Nov. 4, 1912; Poko, 1 (alcoholic), Aug. 

 30, 1913; Garamba, 1, March 15, 1912. 



Collectors' measurements of the Bafwabaka series (10 males and 10 

 females, all adult): 



Total length Head and body Tail Foot Ear 



^ 74.6 (72-78) 42.6 (37^47) 32.8 (31-37) 7.0 (7-7) 11.7 (11-12) 

 9 74 . 6 (68-79) 42 . 7 (37-47) 32 . 7 (30-37) 6 . 7 (6-7) 11.9 (11-12) 



Forearm (from skin, same specimens) 31 (29.8-32); 9 31.6 (30.7- 

 32); forearm, 6 alcoholics (3 males, 3 females) from same locality, 30.8 

 (29-31.5). 



Collectors' measurements of the Niangara series (3 males and 6 females) : 

 Total length, 76 (74-77); head and body, 41 (38-43); tail, 35 (33-37); 

 foot, 6.9 (6-7); ear, 10.1 (10-11). Forearm (same specimens), 30.9 (30- 

 31.9). 



The Bafwabaka and Niangara specimens are indistinguishable, either 

 in size or coloration, and the specimens from the other localities are not 

 distinguishable from those from Bafwabaka and Niangara. 



The range of color variation in fully adult individuals is slight, the dark 

 brown tone of the upperparts, which has a faint reddish cast, is slightly 

 lighter in some than in others, and the same is true of the dull, pale buffy 

 brown of the ventral surface. Immature specimens are much darker — 

 blackish brown, in some cases nearly black. 



In studying the above recorded material I have had for comparison with 

 it seven skins and skulls (also additional skulls) from the Yala River, 

 British East Africa, collected by H. J. A. Turner, and one specimen from 

 Ruwenzori East, collected by R. B. Woosnam, all identified as Pipistrellus 

 nanus. 1 These specimens are essentially the same in size and coloration 

 as my specimens from the Congo Basin. They average slightly darker but 



1 Borrowed from the United States National Museum. 



