DASYPOGON'INAE 



ROBBER FLIES OF THE WORLD 



77 



sides several other bristles still lower and opposite the 

 upper part of the subepistoma. The slender proboscis 

 extends distinctly beyond the face, is held obliquely for- 

 ward, tapers from the base to the blunt, slender apex ; it 

 is laterally compressed at the base; and bears only a 

 few, fine hairs at the base and a few at the extreme 

 apex ; on each side about midway is a longitudinal de- 

 pression. Palpus appears to consist of two segments 

 but with the basal segment fused to the lower part of 

 the head ; second segment small and clavate with a few 

 weak bristles at and near the apex. The antenna is 

 attached at the upper fourth of the head and is consider- 

 ably longer than the head. The first segment is four or 

 five times as long as wide with 7 moderately long, weak 

 bristles below; second segment beadlike, a little more 

 than a fourth as long as the first segment. The third 

 segment, excluding the distinct microsegments, is 

 slender but longer than the first two segments com- 

 bined ; near the apex it tapers until its width is only half 

 as great as in the middle of this segment. Two micro- 

 segments are present, the first quite short, the second 

 longer, wider, blunt, cupshaped and with enclosed spine. 



Head, anterior aspect : The width of face beneath the 

 antenna is a fourth the head width ; face with parallel 

 sides, no wider below. The whole surface is densely 

 appressed micropubescent. The front is small and 

 short due to the fact that the antenna is placed high on 

 the head, and the front across the middle is wider than 

 the face but is again narrowed toward the vertex. Ver- 

 tex very little less wide than the face. Ocellarium small 

 and low but with steep sides and without bristles or 

 pile. Sides of the front along the eye margin with 4 

 small, short, fine, yellowish hairs. 



Thorax: The thorax is rather low, the surface is 

 largely bare and shining but with rather abundant, 

 minute, appressed setae. The humerus is unusually 

 long and gently sloping backward. The prothorax is 

 also longer and more extensive than in Atomosia Mac- 

 quart. The scutellum is flattened on the disc, hemi- 

 circular, but with the scutellar margin nearly rectangu- 

 lar. It bears a pair of stout, moderately long, widely 

 spaced bristles and an additional pair not quite so stout 

 on each side, not far from the base. There is no dif- 

 ferentiated acrostical or dorsocentral pile or bristles on 

 the mesonotum and the scanty discal hairs of the scutel- 

 lum are short and appressed. Notopleuron with 2 

 rather long, stout, reddish bristles, supraalar region 

 with 3 of decreasing thickness and length and the post- 

 alar callosity with 1 stout bristle, quite long and 1 

 shorter, more slender bristle. Pronotum, humerus, the 

 notopleuron narrowly, the area above the wing nar- 

 rowly and the margin of the scutellum, except at the 

 apex, all pollinose, or covered with very fine micro- 

 pubescence. The sides of the metanotum without pile 

 or bristles. Upper posterior corner of the mesopleuron 

 with a single, rather conspicuous, long bristle. "Whole 

 pleuron covered with pale pollen ranging into fine mi- 

 cropubescence and with a few, fine, scattered, short hairs. 

 The convex and protuberant metapleuron with a nar- 

 row band containing 4 long, slender bristles and 8 long, 



bristly hairs. Postmetacoxal area widely membra- 

 nous. Posternum fused as in Laphystia. 



Legs: All the femora are moderately stout without 

 being swollen. Dorsal pile of all the femora moder- 

 ately abundant, appressed and setate. The femora are 

 large, bare and shining ventrally, except that the hind 

 femur ventromedially bears a rather dense band of 

 moderately long, erect pile not reaching the base ; the 

 hind femur also has 1 or 2 longer, slender bristles ven- 

 tromedially near the base. The ventromedial surface 

 of the hind tibia has a similar band of conspicuous, 

 rather dense, erect pile throughout nearly its whole 

 length, wdiich changes to appressed setae at the apex. 

 Hind tibia with 3 moderately strong dorsolateral bris- 

 tles, 4 ventrolateral, and no posterior elements. Hind 

 tarsus slender ; the first segment as long as the next three 

 segments, the fourth and fifth of equal length and bead- 

 like. Middle femur with a long, slender bristle at base 

 below and 2 bristly hairs; also at the outer fifth with 1 

 anterior bristle and 1 anterodorsal bristle. Middle 

 tibia with 3 moderately stout, long, anterodorsal bris- 

 tles, 3 equally long posteroventral bristles and 3 long, 

 ventral bristles, besides 3 much shorter posterodorsal 

 bristles. Anterior femur with a long, bristly hair at 

 base below, a weak bristle anteriorly at the apex and 2 

 posterodorsal bristles near the apex, one much closer 

 to the apex than the other. Anterior tibia with 3 short 

 dorsomedial bristles, 2 scarcely longer posterodorsal 

 bristles, and with 2 much longer posteroventral bristles 

 lying beyond the middle; also, there are 2 ventral bris- 

 tles beyond the middle. Claws long, sharp, only 

 slightly curved at the apex and slender. Pulvilli long, 

 wide, the empodium bladelike. 



Wings : The wings are broad, everywhere villose ex- 

 cept in the middle of the first and second basal cells, 

 and the whole wing is hyaline. The marginal cell is 

 rather widely open by almost its maximal width, the 

 anterior branch of the third vein rises abruptly but is 

 broadly arched and the whole sigmoid. First posterior 

 cell open but narrowed to a little less than half its maxi- 

 mal width. Upper anterior intercalary vein straight 

 and quite rectangular to the third vein, the medial cross- 

 vein short and pulled backward. Fourth posterior cell 

 closed and stalked. Anal cell closed with very short 

 petiole. Posterior crossvein present. Alula present 

 but only moderately deep. The anterior crossvein en- 

 ters the discal cell just before the basal third. The 

 third vein branches just beyond the end of the discal 

 cell. 



Abdomen : The abdomen is convex, relatively narrow, 

 with parallel sides to the end of the fourth segment and 

 not wider than the mesonotum. The pile is dense, ap- 

 pressed and setate, with posterior bands of coarser, pale 

 setae across the apical margins, which widen somewhat 

 toward the sides of the tergites ; in the posterior corners 

 these bands bear underlying pollen, especially on the 

 second and third segments. Only the sides at the base 

 of the first tergite bear a few, longer, erect hairs. The 

 first four tergites each bear laterally vertical rows of 

 conspicuous, stout, pale bristles, 4 near the base of the 



