88 
Psyche 
[Vol. 92 
straight; gonocoxal apodemes short, slender; posterior margin of 
hypandrium with a short, more or less quadrate process that is 
complex and membranous in part; gonostylus of moderate size, 
external margin strongly bent near middle, apex sharply rounded in 
dorsal view, internal surface invaginated medially; aedeagal com- 
plex (Figs. 4, 5) small and simple, only slightly arcuate in profile, 
aedeagus and aedeagal valves apparently strongly fused, thus the 
posterior part of the complex consists of a single lobe, with a simple 
attachment structure; epandrium (Fig. 3) slightly broader than long, 
only narrowly emarginate on anterior margin, thus almost plate 
like, rounded, with feeble emargination along posterior margin; 
cerci short, rounded, only slightly longer than wide. Length 5.3 mm. 
Female. Unknown. 
Remarks. The following key, compiled mostly from Lindner’s 
original descriptions and figures, will serve to identify all known 
species of Nothomyia from South America, and will succinctly 
compare N. fallax with them. 
Key to South American Nothomyia 
1. Legs extensively yellow; wings brownish gray with three milky 
white crossbands N. fasciatipennis (Lindner) 
Legs mostly blackish, only yellowish on some tarsomeres; wings 
may be infuscated, but are without distinct crossbands 
2 
2. Halter yellowish; last antennal flagellomere very slender, arista 
like (Lindner, 1935: Fig. 10); R 4 present or absent ... 3 
Halter dark brownish; last antennal flagellomere thickened 
basally (Fig. 1; Lindner, 1935: Fig. 11); R 4 absent ... 4 
3. R 4 present N. longisetosa (Lindner) 
R 4 absent N. borgmeieri (Lindner) 
4. Apex of wing hyaline, contrasting with subapical infuscation; 
sixth antennal flagellomere of male gradually attenuate 
toward apex N. fallax (Enderlein) 
Apex of wing infuscated, not contrasting in coloration with 
sub-apical region; sixth antennal flagellomere of male more 
strongly attenuate, the apical portion very narrow, nearly 
hair like N. lopesi (Lindner) 
