THE FAMILIES AND GENERA OF BATS. 
183 
Genus NATALUS Gray. 
1838. Natalus Gray, Mag. Zool. and Bot:, II, p. 496, February, 1838 ( strami - 
neus). 
1855. Spectrellum Gervais, Exped. du Comte de Castelnau, Zool., Mamm., 
p. 51 ( macrourum ). 
1878. Natalus Dobson, Catal. Chiropt. Brit. Mus., p. 341 (part). 
1892. "Natalis Winge, Jordfundne og nulevende Flagermus (Cliiroptera) fra 
Lagoa Santa, Minas Geraes, Brasilien, p. 36. 
1905. Spectrellum Elliot, Field Colurnb. Mus., Publ. 105, Zool. Ser., VI, 
p. 501, November, 1905. 
‘Type- species. — Natalus stramineus Gray. 
Geographic distribution. — Warmer parts of America, north to cen- 
tral Mexico, and in the West Indies to Santo Domingo. 
Number of forms . — Three species of Natalus are now known — N. 
stramineus Gray, N. mexicanus Miller, and N. major Miller. 
Characters. — Dental formula: 
-2 3.1.- 2 34567.2-2 1-1 3-3 3-3 on 
1 2 3. 1. - 2 3 4 5 6 7 '' 3 - 3’ e 1 - V^ m 3-3 ’ m 3 - 3 _t58 - 
Upper incisors low and strong, subequal or the outer slightly the 
larger, the four teeth in a straight line, broken in the middle by the 
shallow palatal emargination. The teeth of each pair are of equal 
height, slightly exceeding cingulum of canine, and are strongly in 
contact at middle, the tips diverging on account of the strong con- 
cavity on outer side of outer tooth and on inner side of inner tooth ; 
cingulum indistinct, that of outer tooth strongly oblique. Outer 
incisor separated from canine by space about equal to diameter of 
its crown; median space equal to length of pair of incisors. Lower 
incisors small, trifid, the middle lobe distinctly the largest, the three 
teeth forming a strongly convex row between canines. Upper canine 
high, well developed, the shaft appearing compressed by reason of 
the extensive though shallow concavity of its inner surface ; cingulum 
distinct, though small and without secondary cusps. Lower canine 
with exceptionally slender, subterete shaft. Upper premolars not 
strongly contrasted in size and form, though the posterior tooth is 
larger than either of the others. Each has a distinct, somewhat 
transverse cutting edge, a well-developed cingulum, and no secondary 
cusps. The middle and posterior teeth have a distinct inner poste- 
rior extension scarcely indicated in the first. Lower premolars com- 
pressed, well developed, closely similar to each other in size and form, 
the anterior tooth with the cusp slightly less acutely pointed than in 
the others. Molars normal ; m 3 exceptionally large, its area nearly 
equal to that of m x , its metacone and third commissure well devel- 
oped. In all three teeth there is a faintly indicated hypocone. 
Anterior surface of m 1 and m 2 scarcely or not emarginate. Lower 
