THE FAMILIES AND GENERA OF BATS. 183 



Genus NATALUS Gray. 



1838. Natalus Gray, Mag. Zool. and Bot, II, p. 490, February, 1838 (xtrrtmi- 



neus). 

 1855. Spectrellum Gebvais, Expgd. du Comte de Custelnau, Zool., llitnuu., 



p. 51 (macrourum). 

 1878. Natalus Dobson, Catal. Chiropt. Brit. Mus., p. : J .41 (part). 

 1892. Natalis Wingb, Jordfundne og nulevende Flagermus (Chiroptera) fra 



Lagoa Santa, Minas Geraes, Brasilien, p. 36. 

 1905. Spectrellum Elliot, Field Columb. Mus., Publ. 105, Zool. Her., VI, 



p. 501, November, 1905. 



Type-species, — Natalus stramineiis 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. -234567 . 2-2 1-1 3-3 3-3 



1 2 3. 1. - 2 3 4: 5 6 7 * 3 - 3' c 1 - V pm 3 - 3' m 3 - 3 -38 ' 



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 1 , its metacone and third commissure well devel- 

 oped. In all three teeth there is a faintly indicated hypocone. 

 Anterior surface of m x and m 2 scarcely or not emarginate. Lower 



