640 MOSQUITOES OF NORTH AMERICA 



each lobe with a group of rather dark brown bristles. Postnotum elliptical, 

 prominent, blackish, nude. Pleurae blackish, coxae brown, the vestiture of flat 

 white scales and short pale bristles. 



Abdomen subcylindrical, flattened, gradually tapering posteriorly, last seg- 

 ment small ; dorsal vestiture of black scales, with a narrow band of white ones at 

 base of each segment except the last, the pale bands widened to subquadrate 

 patches at the sides, visible dorsally on sixth and seventh segments ; first seg- 

 ment with white scales dorsally and many pale setae ; venter creamy white scaled, 

 with broad, blackish apical bands, the first two segments entirely white scaled. 



Wings moderate, hyaline; stem of second marginal cell much shorter than its 

 cell, that of second posterior about equal to its cell; basal cross- vein distant a 

 little more than its own length from anterior cross- vein; veins brown, scales 

 black except for a short distance on costal edge at base, where they are white, the 

 outstanding scales on apical half of wing broadly ligulate. Halteres white, with 

 blackish, white-scaled knobs. 



Legs rather long and slender, black scaled ; femora black, white at base beneath 

 and at extreme apex ; tibiae black, narrowly white at base and apex ; hind tarsi 

 black, each joint with a moderate white ring at base and apex, the last joint 

 entirely white; fore and mid tarsi with the white markings obsolete on last 

 three joints. Claw formula, 1.1-1.1-0.0. 



Length : Body about 4 mm. ; wing 3.5 mm. 



Male. — Proboscis long, slender, straight. Palpi slender, straight, not en- 

 larged apically, about three-fourths as long as the proboscis, entirely black 

 scaled, apex of long joint and last two joints with short and rather sparse black 

 hairs. Antenna plumose, the last two joints long and pilose, the others short, 

 grayish, the incrassated rings at insertions of the whorls darker; hairs long, 

 moderately dense, brown. Coloration similar to the female. Wings narrower 

 than in the female, stalks of the fork-cells longer, the vestiture less abundant. 

 Abdomen long, depressed, straight-sided, the dorsal bands broader, the last 

 segment white scaled above ; lateral ciliation rather short but coarse, blackish, 

 abundant on distal half. Claw formula, 3.1-3.1-0.0. 



Length : Body about 4.5 mm. ; wing 3 mm. 



Genitalia (plate 31, fig. 310) : Side-pieces over twice as long as wide, broadly 

 conical at tip, apical lobe undeveloped, basal lobe represented by an area of dense 

 short setae on tubercular bases. Clasp-filament long, slender, uniform with a sub- 

 apical notch bearing a minute seta and a long articulated terminal spine. Harpes 

 narrow, concave, inner margins strongly revolute, tips bent over outwardly, 

 minutely denticulate. Harpagones with a ligulate stem which is excurved in 

 middle and bears an apical articulated filament, slender, curved, not as long as 

 stem. Unci forming a short stout cone with a rounded apex. Basal appendages 

 very small, with a few minute setae. 



Egg (plate 145, fig. 667). — Black, over three times as long as thick, sub- 

 fusiform, rounded at both ends, slightly flattened on one side, the surface with 

 irregular more or less transverse wrinkles and finely granular, the whole with 

 a gelatinous covering, a clear cushion at the micropylar end. 



Larva, Stage IV (see figure of the entire larva, plate 60). — Head rounded, 

 slightly narrowed before eyes, a slight notch at insertion of antennae, front mar- 

 gin broadly arcuate. Antennae moderate, slender, nearly uniform, sparsely 

 spined all over ; tuft of two hairs a little beyond the middle ; four small terminal 

 spines of very uneven length and a small digit on a pedestal. Eyes large but 

 not elevated, transverse, pointed. Both pairs of dorsal head-hairs single ; ante- 

 antennal tuft of four hairs. Mental plate widely triangular, the central tooth 

 large, with ten side teeth which become larger and more distant basally to the 

 last two, which are small. Mandible quadrangular, spined at base without; two 



