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



east as Penge, and also at Niapu and Poko in the Uele. They were still 

 common at Niangara and Vankerckhovenville, and one specimen was taken 

 in the lower Congo at Leopoldville. We have heard them along the rivers 

 wherever suitable forest is abundant, as far northward as Aba, Yakuluku 

 and near Bafuka. They range from southern Nigeria and Angola eastward 

 to Lake Victoria. 



3. Hypsignathus monstrosus H. Allen. 

 Plate XLIV, Fig. 4; Text Figs. 2 (p. 419), (p. 485), 18, 19, 20. 



The hammer-headed bat with its strangely truncate head is much better 

 pictured by its scientific name, which refers to the enormously swollen nasal 

 region of old males, the monstrously developed pendulous lips, the grotesque 

 ruffles around the nose, the warty snout, and the hairless split chin (Text 

 Fig. 2). 



In adult males, which are much larger than the females, the cheek- 

 pouches are extraordinarily developed, extending beneath the entire face 

 anterior to the eyes. All this skin, as well as the upper lips, hangs loose. 

 Only about the nostrils is it firmly attached, but the pouches of the two 

 sides are completely separated by a thin, elastic median partition along the 

 broad ridge of the rostrum, where the skin is much thickened and provided 

 with numerous fibers of striated muscle. Beneath it two tube-like pro- 

 longations of the cheek-pouches run back close along the mid-line to be- 

 tween the ears, where the short hair on the top of the face ends. The 

 lower lips are only attached to the inferior border of the rami and are free 

 as far back as the last molar. In the region of the symphysis their muscular 

 attachment is especially peculiar (Text Fig. 18). 



In general color H. monstrosus is nearly uniform grayish-brown, with a 

 slightly paler abdominal patch, a lighter grayish band across the breast, 

 and a white tuft of hair near the base of the ear. This is by far the largest 

 fruit-bat found in Africa, with a wing-spread of 3 feet 2 inches (967 mm.) 

 and a total length of 10.25 inches (260 mm.). They bear only one young, 

 as shown by dissections of several females, each of which had a single foetus, 

 in May and December. We therefore assume that they reproduce through- 

 out the year. 



When hanging at rest they fold their wings so as to form a rain-proof 

 cover over the breast and belly. During the day we observed them, either 

 singly or in small groups, in the denser foliage high up in the trees, or even 

 in the undergrowth. Near the bank of the Nepoko River at Bafwabaka, 

 in May, 15 of them were discovered some 60 feet from the ground, so close 



