THE FAMILIES AND GENERA OF BATS. 
143 
low, flat, rounded crowns. They are almost equally spaced or thrown 
into two pairs by wider median gap. Upper canine with cingulum 
obsolete, but represented anteriorly and posteriorly by short though 
well-developed cusps, that at posterior base of main shaft the more 
conspicuous. Lower canine with large cingulum, but no secondary 
cusps. Premolars long and narrow, with high main cusps and dis- 
tinct though small styles; anterior lower premolar (pm 2 ) noticeably 
concave on inner face and slightly convex externally. Molars show- 
ing no special peculiarities, except that the W pattern in m 1 is 
distorted by the great length and narrowness of the outer section 
of the tooth, and m 2 has the form usually characteristic of m 3 . 
Inner edge of upper molars broadly convex. Skull of the normal 
Glossophagine type; zygomata slender, but complete; pterygoids 
rather short and thick, but not specially modified in form. Tail 
absent. Inter femoral membrance very narrow. Calcar small, but 
distinct. 
Species examined. — Leptonycteris nivalis (Saussure) and L. 
curasoce Miller. 
Remarks. — The genus Leptonycteris is well characterized by its 
unique dental formula, though externally it rather closely resembles 
Anoura and Lonchoglossa. The only other known genus in which 
the third molar is lacking, Lichonycteris , differ^ very conspicuously in 
the peculiar form of the upper incisors and in the absence of the 
lower incisors. 
Genus LICHONYCTERIS Thomas. 
1895. Lichonycteris Thomas, Ann. and Mag. Nat. Hist., 6th ser., XVI, p. 55, 
July, 1895. 
Type-species. — Lichonycteris obscura Thomas. 
Geographic distribution. — Nicaragua and Dutch Guiana. 
Number of forms. — Only the type species has been described. 
Characters. — Dental formula: 
-2 3 . 1 . - - 3456 -. 2-2 1-1 2-2 2-2 
. 1 . - 2 3 4 5 6 - 1 0 - 0 ’ c 1 - 1 ’-^”'' 3 - 3 ’ m 2-2 
Upper incisors evenly and widely spaced between canines, their 
crowns narrow though scarcely trenchant, longer than high, that of 
inner tooth distinctly emarginate on cutting edge, so that it appears 
bilobed when viewed from in front, that of outer tooth with sharp, 
backward-directed cusp near inner edge, and a flattish outer pro- 
jection. Canines simple, with moderately developed cingula, but 
no secondary cusps. Premolars rather short and not as narrow as 
usual, the main cusp well developed except in pm 2 , in which it is 
obsolete, the styles evident but low. Upper molars with W pattern 
obsolete owing to the great reduction of the styles and commissures. 
