THE FAMILIES AND GENERA OF BATS. 97 
it with the Chilonycterinae (‘ Mormopini ’) as a section of the Phyl- 
lostomiche. 
Remarks. — That this group should be regarded as a distinct family 
is sufficiently indicated by the peculiarities of the wing, shoulder 
joint, skull, and pelvis. Its relationships, however, are less clear. 
The large trochin and small trochiter with its slight articulation with 
the scapula indicate a low position near the Ivhinopomidae and Em- 
ballonuridae, while the structure of the premaxillaries, though 
obscured by the early fusion of the elements of the rostrum, is not 
very different from that found in Rhinopoma. It seems probable, 
therefore, that the three families originated somewhat closely together 
among the more primitive of the Microchiroptera, though each 
throughout its subsequent development has followed a different path. 
Principal subdivisions . — Two genera may be distinguished among 
the species of Noctilionidae. 
KEY TO THE GENERA OF NOCTILIONtm®. 
Length of tibia and foot together more than half 1 total length ; ’ upper 
molars separated postero-internally by wide spaces ; commissure of 
hypocone in m 1 and m 2 obsolete Noctilio, p. 97. 
Length of tibia and foot together less than half ‘ total length ; ’ upper 
molars separated postero-internally by narrow spaces; commissure of 
hypocone in m 1 and m 2 well developed Dirias, p. 99. 
Genus NOCTILIO Linnaeus. 
1776. Noctilio Linnaeus, Syst. Nat., I, 12tli ed., p. 88. 
1808. Noctileo Tiedemann, Zoologie, I, p. 536 (Naclitlowe, V[espertilio'] lep- 
orinus Linnams). 
1821. Celceno Leach, Trans. Linn. Soc. London, XIII, p. 69 (hrooJcs iana= 
leporinus ) . 
1878. Noctilio Dobson, Catal. Chiropt. Brit. Mus., p. 393 (part). 
Type-species. — V espertilio leporinus Linnaeus. 
Geographic distribution. — Tropical America north to Cuba and 
southern Mexico. 
Number of forms. — Two forms, leporinus and mastivus , the status 
of which is not clearly understood, are now usually recognized. 
Characters. — Dental formula : 
-2 3 . 1 . 4567 
1 - 1 . - 2 - 4 5 6 7 
2-2 
§Ti’ c 
i-i 
l-c 
pm 
1-1 
2 - 2 ’ 
m 
Upper incisors very unequal, closely crowded at middle of space 
between canines ; the inner about twice as high as long, subterete, but 
with noticeable posterior heel, their shafts curving outward distally, 
25733 — No. 57 — 07 m 7 
