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



similar in color. Stranger still, the two species were found as room-mates, 

 and as a matter of fact the smaller individuals were declared by natives to 

 be the young of the larger. 



Out of 20 females of C. russatus examined in September, six had each 

 one fcetus. Both these species are new to science and were taken in the 

 Ituri forest, in the neighborhood of Medje. 



Clinging to the rough, decayed surface of the inside of a hollow tree, 

 with their dark wings tucked closely to their plump bodies, these molossid 

 bats look much more like a curiously glistening dark lump of fungus growth 

 than live creatures (Plate LIV). 



African molossids generally live together in large numbers, only one 

 species inhabiting the same hollow or cave. As an exception to this rule 

 we once found Cheer ephon russatus and Mops congicus forming a large colony 

 in a big hollow tree. Such half-dead giants are often the only reliable 

 witnesses of the height of former forest growth in the neighborhood of vil- 

 lages or in the midst of plantations. They are not considered worth the 

 trouble of felling, as their few stunted branches do not throw the broad 

 shadows that would shut out the sunlight so essential for the successful 

 growth of the one important native staple food, plantains. But as these 

 trees become more and more hollow, many bats attracted by the complete 

 darkness of the sinuous, often labyrinth-like interior find them the most 

 suitable abode in such level forest countries where caves and rocky clefts 

 are rare. They populate them in such numbers that one might speak of 

 hidden bat-cities. From their narrow gates they fly out in even more ghost- 

 like fashion than the bats of temperate climates; because behind the vapor- 

 ous veil of the damp equatorial atmosphere they disappear instantly. The 

 free-tailed bats indeed are the swiftest in flight, and though several may be 

 seen passing about at one time, each one by itself chases in dexterous 

 swoops the insects it is most fond of, often some two hundred feet from the 

 ground above the dense canopy of the forest, or else lower down about the 

 clearings. 



During one of the violent storms that periodically test the stability of 

 such weather-beaten trunks, it happened that the home of an especially 

 large colony not far away from our camp was completely shattered. There 

 we discovered C. russatus and Mops congicus together. The catastrophe 

 happened in the early afternoon when they all were resting. It seems sur- 

 prising that in the thundering fall very few bats met their death, but most 

 of them accommodated themselves quickly inside the hollow fragments, from 

 which native children chased them out. Those driven out, when touched, 

 would stop for a moment and lifting their heads would squeak, all the while 

 keeping their mouths wide open and rapidly following the movements of 



