518 



and in venation, the third and fourth veins and the upper branch of 

 cubitus ending on wing-margin as shown in Figure 3, Plate XXXIX, 

 while the venation of infuscatits is as shown in Figure 2. 



(The fore tarsi are absent from type.) 



Length, 3 mm. 



Type localitv, Dubois, 111., April 24, 1914 (C. A. Hart and J. R. 

 Malloch). 



A female taken at Muncie, May 24, 19 14, by the same collectors 

 may belong to this species. It differs from the male in being pale 

 yellow, and in having the vittae black, bases of abdominal dorsal seg- 

 ments brown, and apices of femora, of tibiae, and of all tarsi blackish 

 brown. The wings are slightly grayish. 



The basal joint of fore tarsi is very slightly over half as long as 

 fore tibiae (16:30), and the venation is similar to that of male at 

 apex of wing, though the first vein ends less than midway from cross 

 vein to apex of third. 



6. TrichocIvAdius distinctus, n. sp. 



Male. — Black, opaque. Head yellow, antennae black, plumes fus- 

 cous, whitish at tips. Thorax usually opaque black, with lateral mar- 

 gins, the spaces between the vittae, and the upper margin of pleurae 

 yellow, but rarely yellow with the black areas much restricted. Abdo- 

 men velvety black, hypopygium, posterior half of dorsal segments 5 

 and 6, and the basal two segments and the lateral margins of the other 

 ventral segments yellow. Legs yellow, coxae, extreme apices of tibiae, 

 and apical joint of tarsi blackened. Wings whitish, veins colorless. 

 Halteres yellow. 



Antenna slightly longer than head and thorax together. Prono- 

 tum of moderate width; mesonotum not produced much in front. 

 Hypopygium as in Figure 5, Plate XXXVII. Legs rather stout; fore 

 tarsi without long hairs, basal joint three fifths as long as fore tibiae; 

 mid and hind legs with moderately long hairs; all tibiae with distinct 

 spurs. Third vein ending almost directly above the point where the 

 anterior branch of cubitus reaches the wing-margin ; cross vein dis- 

 tinctly in front of wing-middle ; cubitus forking slightly beyond cross 

 vein ; none of the veins dilated. 



Female. — Differs from the male in being much paler in color; the 

 thorax is yellow, with the vittae, a large portion of sternopleura, a spot 

 in front of wing-base, and the greater portion of the postnotum 

 opaque black. The dorsum of the abdomen is opaque black, the seg- 

 ments having very narrow pale posterior margins except the apical 



