1917.] 



Lang and Chapin, Field Notes on African Chiroptera. 



547 



differs markedly from the ventral side. A great white patch extends from 

 the breast to the vent and then forward over the wing membrane to the 

 armpit as a narrow band of silky white hair. The white, forming thus a W, 

 is interrupted by the dark sides, which fuse with the white-tipped brown hair 

 of the breast and throat. Though distinguished by its much lighter under- 

 side it strangely resembles Cheer ephon cristatus, found 25 miles upstream, in 

 the houses at Boma. 



It also shows a tiny crest, noticeable in both sexes, but curiously enough 

 much less pronounced in the six males, where it is represented by only a 

 few short dark hairs, than in several of the females (of which we have 16). 

 The latter have a distinct dense patch of coarse, wavy, brown hair just in 

 the center of the back of the membranous skin connecting the ears. This 

 is contrary to what we find in Choer ephon abce, where only the males have a 

 crest, and in Mops osborni where it is also better developed in that sex. 



One evening at Malela, as we watched the numerous palm-swifts that 

 shot back and forth between the great fronds of the few fan-palms near the 

 shore, we saw a bat flying out from underneath the dense entangled masses 

 of dead leaves. Next day a native climbed up, and though he saw several 

 bats clinging close to the trunk, he killed but one. Here, as in so many 

 other instances, the kindly influence of M. Quiton aided us in the enrich- 

 ment of our collections, so we were enabled to secure 22 specimens. 



Cheer ephon f rater, then unknown to science, was found to be the only 

 common bat at Malela, as all our efforts to secure other species proved fruit- 

 less. It lived in numbers in that part of the gable of the houses which was 

 generally shut off, clinging in the interstices beside the rafters, several 

 often close together. But as soon as we entered their hiding place they all 

 took wing, making a whirring noise, and many of them sought refuge in the 

 other houses in spite of the bright sunshine. This bat was often observed 

 to fly swiftly between the many narrow lanes of the tall mangrove swamps 

 of that portion of the estuary. Since it seldom frequented the open places 

 over the post, it evidently prefers the wide expanses of water, over the surface 

 of which it skims with great speed; but at times it was seen rather high in 

 the air. The stomach contents show that it feeds on insects without hard 

 integuments. 



56. Chaerephon russatus sp. nov. 

 Plate LIV. 



The warm rufous-brown upper surface of Cheer ephon russatus merges 

 gradually in the lighter, grayer belly. It is only 4 inches (102 mm.) in 

 length, and 11.5 inches (292 mm.) across the outspread wings. In Mops 

 congicus it has a perfect counterpart, about one third larger, and very 



