ALLEN: BATS FROM BRITISH EAST AFRICA. 329 



to the bases of the hairs. The muzzle in front of the eyes is nearly 

 naked. 



Wing membranes dark, and attached at the base of the first digit 

 of the foot. Ears pale brownish. Hair of the body does not extend 

 on to the interfemoral membrane. Calcar well developed with a 

 conspicuous, low, rounded lobe at about 3 mm. behind the heel. 

 Tragus with a distinct external basal lobe. Tip of tail free from the 

 interfemoral membrane. 



Skull. — The skull of the type is scarcely to be differentiated from 

 that of the American species, N. humeralis, except by its slightly 

 smaller size. The upper incisors, however, are set much more nearly 

 at right angles to the long axis of the skull, so that viewed from above 

 they hardly project beyond the premaxillae, whereas in humeralis 

 they extend prominently forward. 



Measurements. — The following measurements were taken in the 

 flesh: total length, 85 mm.; tail, 35; hind foot, 6.5; tibia, 13; calcar, 

 17.5; ear, 12; forearm, 33. Third metacarpal, 29.7. 



Skull: greatest length, 13.6; basal length, 10; palatal length, 5; 

 interorbital width, 4; zygomatic width, 9.4; mastoid width, 8; upper 

 cheek teeth, front of canine to back of m 3 , 4.5; lower cheek teeth, 5.3; 

 mandible, 10.2. 



Remarks. — The discovery in East Africa of this genus hitherto 

 known only from the southeastern United States and Cuba is one of 

 the most important and interesting results of our expedition. Mr. 

 Gerrit S. Miller, Jr., who examined the specimen, first called my 

 attention to the fact that it is in all respects a typical Nycticeius, 

 agreeing with the American species in all essential characters. The 

 postcalcaneal lobe is well developed in the African but scarcely at all 

 in the American bat, and the incisors of the former are less projecting, 

 but otherwise they differ hardly at all except in color and size. 



The single specimen on which this species is based was shot shortly 

 after sunset as it was circling about in an open space among the ivory- 

 nut palms by the Meru River. The river here runs through a dry 

 plain, and no doubt the pale coloration of the species is due to the arid 

 conditions under which it lives. 



From a zoogeographic point of view the discovery of this genus in 

 Africa is of extraordinary interest. Its case is somewhat paralleled 

 by that of Mormopterus which occurs in Cuba, South America, Africa, 

 and Madagascar. Possibly Nycticeius may yet be found to occur in 

 South America. 



