PROC. EXT. SOC. WASH., VOL. 20, XO. 6, JUNE, HHs 129 



the apical surface covered with fiat silvery-white scales. Occiput clothed 

 with black and white scales, a median dorsal white stripe extending from 

 the nape to the antennae, lower down on each lateral surface a wide white 

 stripe also extends from the nape to the eye margin, all three of the sewhite 

 stripes being connected by a stripe of white scales, along the ocular margin, 

 black areas between these white stripes, the lower cheeks covered with wide 

 white scales; several coarse light-brown bristles along the ocular margin 

 project forward, slender upright forked scales on the nape. 



Prothoracic lobes well separated, ornamented with a central stripe of 

 white scales; other parts of lobes black scaled. Mesouotum clothed with 

 black scales and ornamented with four longitudinal lines of narrow, curved 

 yellowish-white scales, the two median lines extending unbroken from the 

 anterior edge to the scutellum, the two outer ones 'extending anteriorly from 

 the scutellum and terminating in conspicuous round spots of broad snow- 

 white scales on each side of the disk, a thin border of these yellowish-white 

 scales also present around the anterior margin of the mesothorax; a large 

 white spot near the base of each wing root. Pleurae arid coxae dark-brown 

 with a number of patches of white scales, these patches varying in size. 

 Scutellum with a patch of yellowish-white scales on each lobe; coarse long 

 bristles also present on each lobe, the center one having four. Postnotum 

 large, prominent, and nude. 



Abdomen long, slender, slowly tapering, subtruncate at tip; vestiture 

 of brownish-black scales with a blue iridescence in some reflections; basal 

 segmental patches of silvery-white scales, wideh* triangular patches of 

 these white scales are also present on the lateroventral surfaces of each 

 segment, those on the posterior segments rough and outstanding; the apical 

 end of the eighth segment fringed with scales and hairs projecting poste- 

 riorly. 



Wings somewhat narrow, transparent: length of second marginal cell 

 equal to its petiole, second posterior cell somewhat shorter than its petiole; 

 all veins clothed with long, narrow, dark-brown scales, the vestiture being 

 heaviest on the costal, auxiliary, and first veins. Marginal fringe long, 

 narrow, dark-brown. Halteres with yellowish stems and brown knobs with 

 a small patch of white scales on each knob. 



Legs rather long with femora stout and tibia and tarsi slender. Femora 

 pale whitish beneath on basal half, dark brown above, with conspicuous 

 round spot of white scales on the outer side beyond the middle, and white 

 spot on apical end. Tibiae dark In-own. Tarsi dark-brown and white, the 

 first three joints on the front and mid tarsi having narrow basal rings of 

 white: wide yellowish-white basal bands on hind tarsi. Claws simple. 



Cotypes. Twelve females. Army Medical School-, Washington, 

 B.C. 



These twelve females used as cot ypcs and one male this latter 

 being too badly damaged for descriptive purposes, were taken 



