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 hypocone; to 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 ,. 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; 

 antitragus 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 ornicus (Merriam), E. glaueinus ("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. 



Pia. 47. — Eumops nanus. Type. Adult 



MALE. BOGAVA, CHIRIQUI, PANAMA. 

 No. 0. 7. 11. 99. Bkit. MUS. X 2. 



