DIE OMPHRALIDEN. 
179 
Beine kurz und sehr kräftig. Es sind zwei Arten bekannt, eine aus 
Nordamerika, eine aus Südamerika. 
1. bulbosa Ost.-Sack. cf ? • Bullet. Unit. Stat. Geolog. Surv., III, 275. [ Scenopinus ] 
(1877) ; Coquill., Entomol. News Philad., XI. 500. (1900) ; Aldr., Catal. North 
Amer. Dipt., 249. (1905) — Missouri. VII. 
2. robusta n. sp., cf. 
Bestimmung stab eile der Männchen. 
1. Fühler schwarz. Schüppchen des Körpers gelbweiss. Schwinger braun. Flü¬ 
gel fast hyalin. .. . „„ „„ .. „„ bulbosa Ost.-Sack. 
2. Drittes Fühlerglied dunkelbrotbraun. Schüppchen silber weiss, glänzend. 
Schwinger weissgelb. Flügel braun tingiert.. _ robusta n. sp. 
1. Metatrichia bulbosa Ost.-Sack. 
Syn. Scenopinus bulbosus Ost.-Sack. 
cf J : «First posterior cell closed, petiolate; head, thorax, and the 
sides of the abdomen sparsely covered with coarse, pollen-like grains. 
Antennae black, hardly reddish at the suture between the second 
and third joints. Head and thorax blackish-bronze colored; front of cf 
is an acute triangle, meeting the triangle of the vertex; the line of 
contact of the eyes is thus a very small one ; in the $ the eyes are 
not contiguous, but separated by the moderately broad front ; both 
front and vertex, in both sexes, are sparsely covered with yellowish- 
white, coarse, pollen-like grains Thorax stouter and more gibbous than 
in O. fenestralis, covered above and on the sides with the same 
pollen-like grains, which are not dense enough, however, to conceal the 
ground-color. Abdomen black above; its sides and the venter covered 
with the same grainlike pollen. Halteres brown ; legs black, roots of 
the tarsal joints more less yellowish. Wings subhyahne (cf), sligthly 
brownish anteriorly ( Ç ) ; costal cell brownish. First posterior cell closed, 
fourth vein being incurved towards the third, and ending in it at a 
considerable distance from the margin of the wing; the petiole thus 
formed is about equal in the length to the posterior transverse vein in 
the cf , a little shorter in the ç . Second submarginal cell is nearly as 
long as the first posterior (therefore much longer than in fenestralis):, 
the distance between the two crossveins is a little shorter than the 
great cross-vein. Length : 5—5,5 mm. Missouri, in July. 
The grains of pollen, which distinguish this species appear, under 
a magnifying power of 100—150, like elongated bulbs inserted on short 
stalks.» 
12' 
