m. Femora with erect outstanding scales; occiput broad and exposed. Large species. P. CILIATA. P. HOWARDI PSOROPHORA R. D. mm. Femora without erect scales. n. Clypeus bearing several scales or hairs, scutellum with broad scales only; back of head with broad scales; scales along the sides of the mesonotum narrow; some or the claws toothed; thorax marked with a pair of silvery scaled curved stripes; legs black with white bands at the bases of some of the segments (fig. 134). Yellow Fever mosquito. AEDES (= STEGOMYIA) CALOPUS. nn. With another combination of characters. Numerous species of mosquitoes belonging to several closely related genera, widely distributed over the country. (_Culex_, _Aedes_, _Ochlerotatus_, etc.). CULEX in the wide sense. ii. Metanotum with setæ. _Wyeomyia_ (found in the United States); and related tropic genera. bb. Antennæ composed of three segments with a differentiated style or bristle; third segment sometimes complex or annulate, in which case the empodium is usually developed like the pulvilli, i.e., pad-like (fig. 161 g). c. Empodium developed pad-like (pulvilliform) i.e., three nearly equal membranous appendages on the underside of the claw (fig. 161g). d. Squamæ, head, and eyes large; occiput flattened or concave; third segment of the antennæ with four to eight annuli or segments, proboscis adapted for piercing; body with fine hairs, never with bristles; middle tibia with two spurs; wing venation as figured (fig. 163f); marginal vein encompasses the entire wing. Horse flies, greenheads, deer flies, gad flies TABANIDÆ[I] e. Hind tibia with spurs at tip; ocelli usually present (PANGONINÆ) f. Third joint of the antennæ with seven or eight segments; proboscis usually prolonged. g. Each section the third antennal segment branched. Central American species, _P. festæ_. _Pityocera_ G. T. gg. Sections of the third antennal segment not branched. h. Upper corner of the eyes in the female terminating in an acute angle; wings of both sexes dark anteriorly. _G. chrysocoma_, a species from the eastern states. _Goniops_ Ald.