VESPERTILIONID& 663 



especially when the white-ants are swarming, feeding eagerly upon 

 them as they rise in the air. S. gigas, from Equatorial Africa, 

 with the forearm measuring 3 '4 inches, is by far the largest 

 species. S. albofuscus, from the Gambia, which is readily distin- 

 guished from the other species by its white wings, is an aberrant 

 form, in which the lower premolars are long and not crowded 

 together, and thereby so closely resembles Fesperugo (Scotozous) 

 dormeri as to render it almost impossible to distinguish Scotophilus 

 and Fesperugo. The figured species is from India. 



Nycticejus. 1 This genus, with the same dental formula as 

 Scotophilus, is distinguished by the first lower premolar not being 

 squeezed in between the adjoining teeth, and by the comparatively 

 much greater size of the last upper molar. It includes only the 

 common North American N. humeralis (crepuscularis), a small Bat 

 scarcely larger than the Pipistrelle. It seems, however, as pointed 

 out by Mr. 0. Thomas, that the discovery of Scotophilus albofuscus 

 renders the generic distinctness of Nycticejus no longer tenable, and 

 that the species should be known as Scotophilus humeralis. 



Atalapha* Dentition: i J, c $,p^,m%; total 32 or 30. 

 The five species of this genus, which are confined to the New 

 World, are generally characterised by the interfemoral membrane 

 being more or less covered with hair (in the two commonest species, 

 A. noveboracensis and A. cinerea, wholly covered), and by the peculiar 

 form of the tragus, which is expanded above and abruptly curved 

 inwards. These species have two upper premolars, of which the 

 first is extremely small and quite internal to the tooth-row. 



Harpyiocephalus. 3 Dentition : i , c, T,jpf, m f ; total 34. This 

 genus includes some eight species of small Bats distinguished by 

 their prominent tube-like nostrils and hairy interfemoral membrane. 

 H. suillus, from Java and neighbouring islands, is the best -known 

 species, and another closely allied (H. hilgendorfi) has been described 

 by Professor Peters from Japan. The remaining six species are 

 known only from the Himalaya and Tibet. All appear to be 

 restricted to the hill tracts of the countries in which they are found. 



Fespertilio.* Dentition : i , c \, p f , ra f ; total 38. Next 

 to Fesperugo, this genus includes by far the largest number of species, 

 amounting to over forty; it has, however, rather a wider geo- 

 graphical distribution in both hemispheres, one species at least 

 being recorded from the Navigators' Islands. The species are 

 easily recognised by the peculiar character of the upper incisors, 

 the crowns of which diverge from each other ; by the large number 

 of premolars, of which the second upper one is always very small ; 



1 Rafinesque, Journ. de Physique, vol. Ixxxviii. p. 417(1819). 2 Rafinesque, 

 Precis des Decouvtrtes et Trav. Somiol. p. 12 (1814). 3 Gray, Ann. Mag. Nat. 

 Hist. vol. x. p. 259 (1842) 4 Linn. Syst. Nat. 12th ed. vol. i. p. 46 (1766). 



