258 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 
crown area more than half that of first molar, its antero-internal 
cusp well developed. Lower premolars not peculiar, the bases of the 
crowns about as long as broad, the shaft of the anterior not as high 
as that of posterior, but with about the same area in cross section. 
Molars normal; m 1 and m 2 with the inner section somewhat reduced 
but with distinct liypocone; m 3 with or without distinct metacone 
and third commissure ; lower molars with the cusps in the usual posi- 
tion, but entoconid frequently reduced or obsolescent in m s . Skull 
(figs. 45-47) strongly built, though rather slender and with sagittal 
crest absent or slightly indicated, the rostrum well developed, always 
more than half as long as brain case, the entire dorsal profile from 
nares to occiput nearly straight, or at 
least with no strongly contrasting ele- 
vations and depressions; interorbital 
region and rostrum subterete, in most 
of the species distinctly hour-glass 
shaped ; a slight lachrymal ridge ; pal- 
ate slightly arched, with or without a 
small median anterior foramen, the 
premaxillaries without trace of pala- 
tal branches; pterygoids parallel; 
basisphenoid pits present, well defined. 
External form slender, much as in 
Nyctinomus. Ears very large, rounded 
or squarish in outline, joined across 
forehead, extending slightly beyond 
nostril when laid forward, the ante- 
rior margin without horny processes; 
anti tragus distinct but not thickened ; 
keel greatly developed, flattened and 
expanded at edge; tragus small, flat, 
its upper edge squarish or rounded; lips full and expanded, though 
not conspicuously wrinkled. Muzzle pad well developed, deeply 
emarginate above, its upper edge and median ridge with minute horny 
processes and small spoon hairs. Wings, feet, tail, and membranes 
not peculiar. 
Species examined. — Eumops abrasus (Temminck), E. bonariensis 
(Peters), E. calif brnicus (Merriam), E. glaucinus (Wagner), E. 
maurus (Thomas), E. milleri (J. A. Allen), E. nanus (Miller), E. 
orthotis (H. Allen), E. perotis (Wied), and E. trumbulli (Thomas). 
Remarks . — The members of this genus are easily recognizable by 
their Nyctinomine general form combined with the merely arched 
palate and the strongly projecting upper incisors completely filling 
space between canines. The small upper premolar is usually present 
and well formed. 
Pig. 47.— Eumops nanus. Type. Adult 
MALE. BOGAVA, CHIRIQUI, PANAMA. 
No. 0. 7. 11. 99. Brit. Mus. x 2. 
