I.APHIUINAE 



ROBBER FLIES OF THE WORLD 



387 



cent with a narrow, submarginal band of matted and 

 more erect pubescence ; scales are absent, the upper part 

 of the face has 7 or 8 long, slender, black bristles 

 scarcely more than bristly hairs; subepistoma laterally 

 with a widely spaced fringe of 4 similar, stouter black 

 bristles; the middle face on the lower fourth has a 

 rather dense patch of long, yellowish, somewhat flat- 

 tened hairs; these are about two-thirds as long as the 

 long slender bristles. Front quite short, pubescent, with 

 2 or 3 bristly hairs on the eye margin opposite the an- 

 tenna. Vertex deeply excavated, with strongly sloping 

 sides ; the ocellarium is moderately large and high, with 

 very steep sides and comparatively narrow at the top, 

 steep and abrupt behind. It bears in the middle a pair 

 of long, slender, divergent bristles and behind 2 quite 

 short bristles. Anterior eye facets greatly enlarged. 



Thorax : The pleuron is densely, minutely appressed 

 pubescent on a diagonal band from wing to prosternum 

 and continuing on the anterior coxa. Posterior pleuron 

 less conspicuously pubescent. There tends to be a simi- 

 lar band of brightly colored pubescence, however, run- 

 ning over the posthypopleuron and the posterior coxa. 

 Mesopleuron, including the humerus, shining and bare. 

 Pile of mesonotum dense, bristly and suberect. Acros- 

 tical and dorsocentral elements not differentiated; the 

 humerus has pile similar to the dorsum. The lateral 

 bristles consist of 1 short, slender notopleural, 1 long, 

 moderately stout supraalar, 1 equally long, slender post- 

 alar. The scutellum has 3 pairs of long, bristly hairs 

 and considerable, additional, shorter, bristly pile. 

 Scutellum moderately thick, only slightly convex, with 

 a distinct impressed rim, with bristly pile on the disc 

 and together with the mesonotum strongly punctulate. 

 Propleuron with a tuft of stiff pile ventrally ; pronotum 

 with weak bristles; the upper margin of the meso- 

 pleuron with short pile, its posterior corner with a long, 

 slender but distinct bristle ; pteropleuron apilose ; meta- 

 pleuron with a vertical band containing 5 or 6 long 

 bristles, and some additional pile. Hypopleuron and 

 the postmetasternum with abundant, long, fine pile; 

 lateral slopes of the metanotum with a patch of abun- 

 dant, bristly hairs and several stout bristles. Ventral 

 metasternum chitinized, isolated and bearing long, fine 

 pile. Postmetacoxal area long, with a stout chitinized 

 arch. Tegula pubescent only. 



Legs: All the femora are a little swollen distally; on 

 the hind femur the lateral surface, and the posterior 

 surfaces of the other femora are almost bare. Ventral 

 medial surface of this femur with a fringe of dense, long, 

 fine, pale, erect pile confined to the middle three-fifths. 

 There are also 3 quite long, basally stout, attenuate, 

 ventrolateral bristles on the basal third which cross one 

 another when the legs are adjacent. The hind femur 

 has at the apical third 1 dorsolateral, nearer the apex 1 

 dorsal, and at the apex a pair of short bristles or bristly 

 hairs; laterally there are 2 bristles. Ventral surface 

 of the hind tibia with 3 exceptionally long, outwardly 

 curved, slender, pale bristles on the distal half with a 

 shorter bristle before the middle ; otherwise this ventral 



surface has only 12 or 15 short, bristly hairs except at 

 the apex where there is a conspicuous, very dense tuft 

 of nearly erect, still pile, followed medially and ven- 

 trally :it the apex with appressed, bristly setae. Hind 

 tibia with 4 bristly hairs dorsomedially, but 3 very 

 stout, long, attenuate bristles laterally. Middle femur 

 with a stout anterodorsal bristle beyond the middle, the 

 ventral surface with a fringe of long, bristly hairs. On 

 the middle tibia, oddly, it is the anterior bristles which 

 are emphasized, there being 3 quite long, very stout, 

 attenuate bristles, 1 ventrolateral near the base and 2 

 lateral, 1 before and 1 after the middle ; also 5 shorter, 

 pale, more slender posterior bristles, 3 or 4 still shorter, 

 postero ventral and 2 exceptionally long, pale, ventral 

 bristles, 1 at the basal fourth and 1 just beyond the 

 middle. 



Anterior femur with similar, stout, anterior bristles; 

 its tibia also similar with 3 exceptionally long, ventral 

 bristles, the outer 2 longest and stout and fully half as 

 long as the tibia, and a fourth bristle still shorter and 

 more slender, placed basally; also 3 very long, stout, 

 posteroventral bristles. The anterior tibia also has 

 anterodorsally and posterodorsally 4 or 5 long, slender, 

 bristly hairs, others posteriorly and ventrally. Basi- 

 tarsus slender and elongate and with long exaggerated 

 bristles. Tarsi end in slender, sharp claws, strongly 

 bent at the apex ; pulvilli well developed, the empodium 

 long and bladelike. 



Wings : The wings are characteristically with 2 or 3 

 brown bands, sharply delimited against a greyish 

 hyaline remainder. Marginal cell closed with an ex- 

 ceptionally long stalk. First posterior cell not nar- 

 rowed ; end vein of the discal cell almost exactly in line 

 with the end vein of the fourth posterior cell, the latter 

 cell closed with a short stalk; the anterior crossvein 

 enters the discal cell before the basal fifth. The anal 

 cell is closed with a short stalk; the second basal cell 

 ends in 3 veins, middle vein short. Alula a little wider 

 than the costal cell; costal setae isolated and stout; 

 ambient vein complete. 



Abdomen : The abdomen is elongate but shorter than 

 the wing and robust ; it is not quite as wide as the mes- 

 onotum; the sides are nearly parallel, strongly convex 

 posteriorly; the lateral margins dinstinctly corrugate, 

 the base of one set within the apex of the preceding ; the 

 whole surface grossly punctate. There are seven ter- 

 gites in the female, the seventh is three-fifths as long 

 as the sixth or as little as two-fifths. Terminalia almost 

 concealed in lateral profile but the last two tergites are 

 not produced into a down-turned, cuplike pocket as in 

 Atomosia. Pile abundant but minute and suberect, 

 with a dense, fringelike patch on the basal corners of 

 each tergite. Sides of the tergites characteristically 

 with stout, long bristles in the middle : 3 on the first 

 tergite ; 1 or 2 on the second tergite, and 1 on the side 

 of each of the third to seventh tergites inclusive. Fe- 

 male terminalia rather short and inconspicuous, with 2 

 minute, slender, dorsal protrusions almost hidden. 



