1937] 
Exotic Syrphid Flies 
13 
latter has a brownish rim. The markings unfortunately 
obscured by poor preservation but a yellow tomentose spot 
on the inner medial angles of humeri, a vertical narrow 
similar stripe on the middle of pleurae, and some evidence 
of the same on the posterior calli. Halteres brownish ; stalk 
darker. 
Abdomen black, very dark brown laterally and on the 
posterior half of the last segment and the hypopygium, 
covered with microscopically short, black bristles, some 
scattered short pale pile, and a transverse narrow band of 
pale tomentum on the post border of first segment. 
Legs black, tarsi brown, the femora covered with thick, 
quite long, pale, very fine hair. Hind femora extraordi- 
narily thick. 
Wings with a strong black anterior border, the black 
keeping to the configuration of the third longitudinal vein, 
but filling the anterior part of the first basal and the first 
posterior cells, and the loop of the third longitudinal vein is 
filled, but bears a small clear spot. 
Length 15mm. 
One male. Bolivia. Province of Sara (Steinbach) . Type 
in the Museum of Comparative Zoology. 
This peculiar species is very close to Meromacrus niger 
Sack, from which it differs in the extraordinarily thickened 
hind femora besides other characters. The dull black color 
and femora serve to distinguish it. 
Velocimyia n. gen. 
Small flies. Eyes bare, touching in male for a short dis- 
tance. Face and front heavily pubescent and with some 
longer pile on the former. Face with a very low weak tu- 
bercle on bump in the middle, the lower face bluntly conical. 
Antennae of the simple Eristaliform type ; arista bare, basally 
thickened. Thorax simple. Scutellum small, two or three 
times as wide as long, and without margin. Abdomen taper- 
ing posteriorward, but four segments and tip of hypogynium 
visible. The last segment of the abdomen together with the 
hypopygium wide, round, exceptionally prominent and con- 
spicuous. In this respect the form resembles the new world 
Meromacrus. 
