1917.] 



Lang and Chapin, Field Notes on African Chiroptera. 



497 



PART III. FIELD NOTES. 

 By Herbert Lang and James P. Chapin. 



MEGACHIROPTERA. 



PTEROPODID.E. 



1. Eidolon helvum (Kerr). 1 



Plate XLIV, Fig. 3. 



The color of this large fruit-bat when adult is a distinctive dirty yellow- 

 ish brown with deeper orange tawny hair on the glandular skin on the 

 front of the neck, especially in males. The small free tail is decidedly 

 variable in length, from .25 to .80 of an inch (6 to 20 mm.). In contrast 

 to the epomophorine bats it has a more pointed head, like that of the 

 flying-foxes; the wings are long and narrowed, and spread about 30 inches 

 (755 mm.) though the length from nose to tip of tail is but 8 inches (200 mm.). 

 They are much used in climbing about the boughs on which they roost, and 

 their tips are then folded in precisely the same manner as in the vespertilionid 

 genus Miniopterus (see Fig. 24,- p. 541), the second phalanges of the third 

 and fourth digits being turned inward so as to lie flat on the lower surface 

 of the wing. Perhaps Eidolon is thus better able to search about for fruit. 

 Hypsignathus and the epaulet-bats, on the other hand, have more difficulty 

 in approaching and detaching them; they are not active climbers, and can 

 bend these joints but little inward, using the tips of the wings more often 

 to cover the belly as they hang upside down (see Plate XLVII) . 



Among flocks of Eidolon helvum the immature members are always num- 

 erous, as could be ascertained by looking over the large numbers killed by 

 natives at their roosts. In November at Avakubi, out of 12 females, the 

 five really adult were gravid, four having one foetus and the fifth two. 

 This would indicate the existence of a definite breeding season, although 

 the testes of an old male taken at Avakubi in May (No. 48706) were unusu- 

 ally well-developed, measuring 24 mm. in length. The fur of the front of 

 its neck was moistened with a sticky fluid (not greasy) possessing a slight 

 musky odor, apparently secreted by the skin beneath. At all seasons these 

 bats have a disagreeable smell. 



1 The notation of the species in this list is the same as that of Part I, the numbers prehxed to the 

 names of the species in either list serving as a cross-reference to the same species in the other. 



