260 A. L. MELANDER. 



with a forked third vein ; discal cell present, emitting three veins to 

 the margin ; anal cell longer than the second basal ; anal angle gone. 



Antennae yellow, tliird joint brown ; abdomen yellow, with dorsal dark spots. 



rubertsonii Coquillett. 

 Antennae piceous; abdomen dark fuscous occideii talis sp. nov. 



Brachystoina robertsouii Coquillett. 

 Proc. Nat. Mus., 1895, p. 393. 



Head black, gray pollinose; face naked, scarcely half as wide as the front; an- 

 tennae yellow, the third joint, except at the base and style, brown; the third 

 joint lanceolate, scarcely twice as long as broad, twice as long as the second ; 

 style curved, one-third longer than the third joint; proboscis yellow, palpi wliit- 

 ish. Thorax very shining black ; pleura blackish, opaque light gray pollinose; 

 raetanotum and scutellum the same, the latter bearing two bristles. Abdomen 

 compressed, shining, yellowisli, a large dorsal black spot on each segment; hypo- 

 pygium large, ascending, each upper lamella produced at the outer angles into a 

 pair of long, erect, cylindrical, brown processes; middle lamellae very large, each 

 l>earing at its tip a rather large curved process, in front of which is a small pilose 

 tubercle, while behind it is a smaller tubercle bearing a few long whitish bris- 

 tles; the inner side of each lamella bears a long, cylindrical, brown-tipped pro- 

 cess; filament slender, arcuate, proceeding from apex of the rather large lower 

 lamella. Legs including the coxae yellow ; front and hind femora slender, the 

 middle nearly twice as thick as the front ones, their upper side thickly beset with 

 very short black spines and with longer black bristles; inner side of middle 

 tibiae also thickly beset with very short black spines. Halteres yellow. Wings 

 nearly hyaline, stigma wanting, first basal cell slightly longer than the anal, 

 which is a trifle longer than the second basal. 4 mm. 



Illinois, Tennessee, Ohio. 



Bracliystoina occicleiitali$« sp. nov. (Fig. 89). 

 Male and Female. Length 4 mm. — Head and thorax black, abdomen fuscous. 

 Face extremely narrow, gray (female), obliterated in the male; front moderately 

 narrow, black ; vertex and occiput shining. Antennae equal to head, piceous, 

 third joint subequal to first one, arista white, equalling antenna. Palpi white, 

 proboscis yellow. Thorax shining, humeral callosity more or less fuscous; a pre- 

 alar but no scutellar long bristles; pleurte a little dusted with gray ; halteres yel- 

 lowish. Abdomen twice as long as thorax, fusco-piceous ; of the female com- 

 pressed in all the (dried) specimens, but the terminal segment greatly enlarged, 

 balloon-like. The enlargement is sometimes translucent yellow bronzed. Abdo- 

 men of the male yellowish at the base, black apically, the hypopygium small, 

 terminal, the upper lamellae small, elongate, slender, the outer extremity filiform, 

 the middle lamellte moderate in size, the outer side excised, from the emargina- 

 tion of which arises a slender filiform appendage, the central filament slender, its 

 base moderately thickened, strongly arcuate, and suddenly recurved near the 

 tip. Legs slender, yellow, upper side of four posterior femora, all tibiae and tarsi 

 brownish ; no setulie present. Wings uniformly lightly infumated, veins fuscous, 

 third vein forked, subniarginal cell not closed, basal cells equal, anal cell a little 

 longer, its cross-vein curved, no anal angle. 



Numerous specimens; Washington, Idaho (J. ^I. Aldrich). 



