PSOROPHORA DISCOLOR 579 



scales which hardly more than half rover the dark ground, even in fresh speci- 

 mens, giving the effect of brown with a brassy luster; bristles partly pale, partly 

 brown, rather short. Scutelhim trilobate, the mid lobe prominent, clothed with 

 similar scales as mesouotum, each lobe with about ten fine, long pale bristles. 

 Postnotum elliptical, prominent, blackish, nude, slightly pruinose. Pleurae and 

 C0X86 brown, clothed with narrow, elliptical whitish scales and rather short pale 

 bristles. 



Abdomen subcylindrical, depressed, terminal segments tapered, membrane 

 grayish ; dorsal vestiture of flat yellowish-white and brownish-black scales inter- 

 mixed, and with segmental broad apical bands of white scales, produced cen- 

 trally into a median stripe, the white scales predominating on last segment; 

 first segment with a median patch of white scales and with many long pale setse ; 

 hairs abundant, particularly laterally; beneath the scaling is more confused, 

 the pale scales predominating except on last segment. 



Wings rather broad, hyaline, the veins pale ; stems of l)oth the fork-cells 

 considerably shorter than their cells ; basal cross-vein distant twice its own 

 length from anterior cross-vein ; scales black and dull whitish, arranged in 

 obscure patches; costa nearly entirely black scaled except for a long white spot 

 at outer fourth; a distinct black patch at base of thirct vein and a longer one 

 proximally on upper branch of fifth vein ; bases of second marginal and second 

 posterior cells and tips of all the veins dark scaled ; fifth vein black scaled up to 

 fork; sixth vein with the apical third dark-scaled; most of the other scales 

 whitish; fringe blackish, unspotted; outstanding scales on outer half of wing 

 linear-lanceolate; a distinct black spot composed of short, subtruncate scales 

 at base of third vein, more diffuse patches of long blackish scales on the second 

 vein at cross- vein and at base of fork and on fourth vein at base of fork. 

 Halteres entirely pale. 



Legs moderately long and slender, pale, clothed with small, flat pale-yellowish 

 scales; upper side of femora and tibiae with black scales intermixed, becoming 

 predominant at tips; femora with an ill-defined ring of pale scales near tip; 

 tibiae with a narrow white ring at base ; knees pale ; tarsal joints black tipped, 

 terminal ones broadly so; second to fovirth joint of hind legs distinctly white 

 ringed at base, rings narrower on outer joints ; front tarsi with last three joints 

 black. Claw formula, 0.0-0.0-0.0. 



Length : Body about 4.5 mm. ; wing 3.7 mm. 



Male. Proboscis straight, uniform, rather slender, entirely dark scaled 

 dorsally, pale scaled medianly beneath. Palpi exceeding the proboscis by more 

 than the length of the last joint, the last two joints long and slightly thick- 

 ened; long joint mostly dark scaled, a pale ring before middle; two last joints 

 black scaled, narrowly white-scaled at bases ; end of long joint and the last 

 joints with many long brown hairs. Antennae plumose, the last two joints 

 long and slender, pilose, the others short, pale, blackish at the swollen insertions 

 of the whorls ; hairs of whorls long, dense, pale, shading to blackish. Coloration 

 similar to the female. Abdomen elongate, depressed, the sides with abundant 

 pale ciliation. Wings much narrower than in the female, the stems of the fork- 

 cells about equal to their cells ; vestiture less abundant, the characteristic mark- 

 ings obscured. Claw formula, 2.1-2.1-0.0. 



Length : Body about 5 mm. ; wing 3.7 mm. 



Genitalia (plate 21, fig. 150) : Side-pieces conically tapered, about twice as 

 long as wide; apical lobe well developed, prominent, conical; no basal lobe. 

 Clasp-filament large, prominently swollen in middle, with a rather large, apical, 

 inserted articulated spine. Harpes concave, broad, inner margin thickened and 

 revolute, tip widely cleft, forming two apical teeth directed laterally. Har- 

 pagones with a small ligulate base and expanded triangulate tip bearing a row 



