VESPERTILIONIDAS 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. 5. 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 Vesperugo (Scotozous) 
dormeri as to render it almost impossible to distinguish Scotophilus 
and Vesperugo. The figured species is from India. 
Nycticejus1—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. O. Thomas, that the discovery of Scotophilus albofuscus 
renders the generic distinctness of Nycticejus no longer tenable, and 
that the species should be known as de! humeralis. 
Atalapha.2—Dentition: + 4, ¢ 1, p >, m4; 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.’—Dentition : 23, ¢,4,p2,m 3; total 34. This 
genus includes some eight species of small Bats distinguished by 
their prominent tube-like nostrils and hairy interfemoral membrane. 
H. swillus, from Java and neighbouring islands, is the best-known 
species, and another closely allied (7. 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 es in wich they are found. 
Vespertilio.A—Dentition: 1 2, ¢ 4, p 3, m4; total 38. Next 
to Vesperugo, 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. lxxxviii. p. 417 (1819). ®? Rafinesque, 
Précis des Decowvértes 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). 
