MACQUARTIA. 129 
the others. A character common to all four is the unusual length of the bristles 
behind the posterior orbits of the eyes. The collections also contain four female 
specimens which undoubtedly belong to one or the other of the first three species; but 
as I cannot find good distinguishing characters common to both sexes, it remains 
uncertain whether I have correctly paired them. The males may be recognized as 
follows :— 
1. Eyes nearly contiguous on the vertex (anal segment 
compressed and pointed) . . ... + 2 2 Q 
Eyes distinctly separated over the whole length of the 
front. . . . ‘ . 3. 
2. Underside of the abdomen with long whitish or ‘yellowish 
hairs. . . . . setiventris, v. d. Wulp. 
Underside of the abdomen with black hairs and bristles . acuminata, v. d. Wulp. 
3. Antenne black; abdomen elongate-conical (the anal 
_ segment compressed), black, with white reflections . venusta, v.d. Wulp. 
Antenne rufous; abdomen ovate, testaceous, with black 
and ochraceous reflecting spots . . . . . . . « versicolor, v.d. Wulp. 
_ 1. Macquartia setiventris, sp.n., ¢. (Tab. III. figg. 21; 21a, the insect 
in profile.) 
Shining black; humeral spots and reflections on the abdomen whitish; eyes nearly contiguous towards the 
vertex; ventral side of the abdomen with long yellowish hairs; antenne and legs black, the tibie of a 
more piceous colour; palpi rufous; wings with a brownish tint along the costa. 
Length 10-5 millim. 
Head whitish, with cinereous reflections ; front narrowed behind in such a manner that the eyes are nearly 
contiguous on the vertex; frontal band black, trigonal; frontal bristles numerous, forming a single row 
on each side of the frontal band; beard and pilosity of the occiput pale yellow; behind the posterior 
orbits of the eyes a row of rather long black bristly hairs; the bristles above the vibriss close together. 
Antenne as long as two-thirds of the face, black, with the basal joints dark rufous; second joint bristly ; 
third joint rounded at the tip; arista thickened in its proximal half. The palpi and the terminal lips 
of the proboscis rufous and bearing some bristly hairs. Thorax black, anteriorly with some grey 
tomentum, in which four black stripes are visible; humeral spots whitish, and prolonged in a band 
towards the root of the wings; a whitish stripe extending obliquely over the pleura and middle coxa ; 
scutellum with long macrochete at the hind margin. The light reflections on the abdomen appear like 
white front borders to the second and following segments; sometimes these front borders become laterally 
broader, and have more or less the aspect of two white spots; the anal segment, seen from above, is 
compressed and pointed, and, seen from the side, obliquely truncated; the genitals are prominent, and 
bear several hairs and bristles; laterally the abdomen has many long bristles; on the ventral side is a 
long pale yellow pile, mixed with some black bristles. Middle and hind tibie rather dark rufous; the 
bristles of the legs numerous and for the greater part long :—the middle femora have on the underside 
some long bristles on the proximal half, and a row of hairs towards the tip; the middle and hind tibie 
have several long bristles ;—the foot-claws and pulvilli are elongate, the pulvilli yellowish. Tegule greyish- 
yellow. Wings grey, dilute brownish along the costa; small cross-vein before the middle of the discal 
cell ; apical and posterior cross-veins slightly curved. 
_ Hab. Mexico, Orizaba (coll. Bellardi), Omilteme in Guerrero 8000 feet (H. H. Smith). 
One male specimen from each of these localities. 
BIOL. CENTR.-AMER., Dipt., Vol. II., May 1890. 8 
