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UNITED STATES NATIONAL MUSEUM BULLETIN 224 



upper half and evident in profile below only because of 

 the retreating eye ; the face is plane and slightly retreat- 

 ing on the lowest part. The subepistoma is small, con- 

 cave, and a little oblique. The occiput is moderately 

 developed at some distance from the eye margin but 

 only along the middle and below. It is concave and 

 sunken on the upper eye corners. On the lower half 

 it bears fine pile; weak bristles in the middle become 

 sharp, stout, straight, and black above ; there are 9 pairs 

 on each side. Proboscis extends a little beyond the 

 face, is bluntly rounded at apex with anteriorly di- 

 rected circlet of hairs. Base below with only a few, 

 short, stiff hairs. The palpus is moderately large, com- 

 posed of two segments ; the second is cylindrical, longer 

 than the first, and bears 6 slender, short bristles. The 

 antenna is attached at the upper third of the head and 

 is moderately elongate. The first segment is nearly 

 twice as long as the second and the third is twice is 

 long as the first two combined. First segment slender, 

 with 2 or 3 setae at the apex dorsally and more setae 

 ventrally over its whole length ; and along the middle 2 

 moderately long, black bristles. The rather beadlike 

 second segment has setae above, and 2 rather long 

 bristles and 2 or 3 shorter bristles below. Third seg- 

 ment slender, attenuate only near the apex, winch ends 

 in fine, short hairs and no microsegment ; dorsally in 

 the middle it bears an incision and pale spines. 



Head, anterior aspect : The head is not quite circular; 

 the width of the head is approximately iy± times the 

 height. The face is quite narrow, about an eighth 

 the head width, with nearly parallel sides; it is very 

 slightly more narrow in the middle than it is beneath 

 the antenna or below. The surface has unusually fine 

 and dense appressed, silvery micropubescence. On the 

 upper part on each side in a vertical row are 3 quite 

 long, comparatively slender, wiry, black bristles and 

 2 other shorter ones along the sides of the subepistoma, 

 and 4 bristly hairs in the middle of the epistomal 

 margin. Front small, a little wider than the face with 

 longitudinal submedial fossa; it is silvery pubescent 

 and has 3 fine, bristly hairs laterally. Vertex narrowed 

 and moderately excavated; the small, high, narrow 

 ocellarium has vertical sides, large anterior ocellus and 

 between them is a pair of long, moderately stout 

 bristles. 



Thorax: The thorax is short and only moderately 

 high. Surface of mesonotum is densely appressed 

 setate and with a dorsocentral row of fine, longer hairs 

 anteriorly and equally fine hairs posteriorly. Lateral 

 bristles are long but slender; they consist of 1 noto- 

 pleural, 1 supraalar, 2 on postalar callosity and the 

 margin of the polished, mostly bare, smooth, slightly 

 convex scutellum bears 4 quite long, basally stout, 

 spikelike reddish bristles; scutellar margin creased. 

 Metariotal callosities with abundant, coarse pile. 

 Pronotum with only stiff hairs. Whole pleuron pol- 

 linose. Upper posterior corner of the mesopleuron at 

 the bottom of the anterior basalare with a long, rather 

 stout, reddish bristle. Metapleuron with a band of 

 long, bristly hairs and similar hairs on the hypopleuron. 



Postmetacoxal area with a wide, complete band of 

 chitin ; prosternmn broadly fused. 



Legs: The hind femur is somewhat longer and at 

 most slightly thickened distally. All the legs bear 

 unusually loose, scanty, fine, subappressed pile dorsally, 

 which is even more scattered on the tibia. Hind femur 

 with 4 long, slender, ventrolateral bristles, distributed 

 along the middle and toward both base and apex it 

 has 1 or 2 additional, shorter, weaker, bristly hairs. 

 The ventromedial surface has 3 similar elements as 

 strong as any on the outer margin; they are confined 

 to the basal third; this surface also has a scattered, 

 ventromedial fringe of long, erect hairs. Hind tibia 

 with more conspicuous bristles which are also slender ; 

 there are 3 quite long, lateral elements, 2 ventrolateral 

 elements in the middle, and 4 equally long, distally 

 curved ventral elements besides a medial fringe of 

 long pile. Medial setae confined only to the apex. 

 This tibia is comparatively slender; the tarsi are also 

 slender though the last 3 segments are more slender. 

 Middle femur with on the outer fourth a rather stout 

 anterior bristle and below it an anterior and posterior 

 fringe of long, bristly hairs or very slender bristles. 

 Middle tibia with strikingly long, basally stout, finely 

 attenuate, reddish bristles. There are 3 anterodorsal 

 bristles, 1 anterior basal, 2 post ero ventral at basal 

 and apical thirds, and 2 similar ventral elements. Also 

 there is a posterior fringe of 5 more slender, shorter 

 bristles. Anterior femur only with ventral bristly 

 hairs and 2 or 3 similar, slender hairs dorsally. This 

 tibia, however, like the middle tibia, has a conspicuous 

 fringe of 3 or 4 exceptionally long, anteroventral and 

 posteroventral reddish bristles, and 4 shorter, more 

 slender, dorsal bristles. Claws slender, sharp, chiefly 

 bent at apex; pulvillus well developed; the empodium 

 is long, bladelike and very fine apically. 



Wings: The wings are nearly hyaline, everywhere 

 villose except in the basal cells which have only small 

 patches. Marginal cell closed with a comparatively 

 long stalk. Anterior branch of the third vein ends 

 barely above the wing apex; the posterior branch ends 

 a considerable distance behind. The second posterior 

 cell is narrowed to half its maximal width; fourth 

 posterior cell and anal cell each closed with a short 

 stalk. Posterior crossvein almost wanting. Anterior 

 crossvein short, entering the discal cell before the basal 

 fourth. Alula narrow, the ambient vein ends with the 

 second posterior cell. 



Abdomen: The abdomen is a little wider than the 

 mesonotum and comparatively long and in consequence 

 with a somewhat slender appearance. It is everywhere 

 punctulate with coarse, appressed setae and some rather 

 long, fine, erect hairs along the lateral margins. The 

 sides of the first tergite have a straight, vertical row 

 of 6 microtuberculate, close-set, long, stout, pale bristles. 

 Lateral margin of the second tergite near the middle 

 with 4 to 5 slender bristles or bristly hairs. Posterior 

 margins of all of the segments before the actual apex 

 with a fine fringe of subappressed hairs. Females 

 with six segments and with the seventh segment quite 



