LAPHRIINAE 



ROBBER FLIES OF THE WORLD 



411 



like hairs begin shortly beneath the antenna. In the 

 female the face is apilose, with a pair of long, slender, 

 black bristles strongly curved, extending forward 

 shortly beneath the antenna and 2 other pairs over the 

 middle of the face, 2 additional long pairs near the 

 bottom of the face, and along the epistomal margin in 

 front 2 or 3 long, slender pairs and other short, bristly 

 pile, besides 4 pairs along the lateral subepistoma. 

 Front quite short, with a row of 4 or 5 slender, bristly 

 hairs along the eye margin. Vertex deeply excavated, 

 with slanting sides ; the ocellarium large, high and witli 

 sleep sides and abrupt behind, bearing dorsally a pair 

 of moderately stout, long, pale, divergent bristles, and 

 between the posterior ocelli a pair of shorter bristles. 

 Anterior eye facets moderately enlarged. 



Thorax : The thorax is densely appressed pubescent 

 on all the pleura but much less conspicuously on the 

 pteropleuron and metapleuron. Mesonotum not pubes- 

 cent, the pile abundant, short, bristly, flat appressed; 

 in the male it is golden anteriorly and slightly but dis- 

 tinctly flattened. Acrostical and dorsocentral elements 

 not differentiated anteriorly but there are 4 pairs of 

 long, slender, posterior dorsocentral bristles. Humerus 

 with abundant, long, bristly pile. In the type of genus 

 the following complement of moderately long, stout, 

 lateral bristles are present : 1 notopleural, 1 or 2 supra- 

 alar, 1 postalar, but no scutellar bristles. Scutellum 

 thin, slightly convex, the margin strongly convex and 

 bearing 3 pairs of short, erect, inconspicuous, bristly 

 hairs. Disc with abundant, short, bristly suberect pile; 

 margin not impressed; base with deep crease. Pro- 

 pleuron with a few stiff hairs ventrally and posteriorly ; 

 the pronotum with longer, similar hairs. Mesopleuron 

 with a few scattered, bristly hairs dorsally along the 

 border and with a conspicuous, rather long and com- 

 paratively stout posterodorsal bristle. Pteropleuron 

 apilose, the posthypopleuron has 5 or 6 long, slender, 

 stiff hairs, the metapleuron has 5 quite long, slender 

 bristles curved downward apically. Lateral slopes of 

 the metanotum with a copious patch of short, stout 

 bristles and bristly pile, pale in the male but black in 

 the female. Postlateral metasternum with abundant, 

 long, fine pile ; the ventral metasternum has a few, fine 

 hairs and a pair of long, anterior, slender, submedial, 

 bristly hairs, the whole is rather weakly chitinized ap- 

 parently and the postmetacoxal area is large, forming 

 an extensive, chitinized arch ; tegida pubescent only. 



Legs : The femora are moderately stout without being 

 noticeably swollen; the middle femur is perhaps very 

 slightly swollen distally ; the dorsal pile of all of them 

 short, appressed and setate, the ventral medial surface 

 of the posterior femur bears a moderately abundant, 

 erect, fringe of fine, long, pale pile from base to apex ; 

 ventral surface of hind tibia with similar, shorter 

 fringe from near the base to the apex ; there is no brush 

 of setae distally though they are well developed and 

 ranked on the first two tarsal segments. In the type of 

 genus the following complement of long bristles is 

 present; on the hind femur a single unusually long, 

 lateral bristle at the outer third ; a short, slender, dorso- 



lateral and dorsomedial subapical bristle and the ven- 

 tral surface near the base with 1 or 2 long, slender, pale 

 bristles. This tibia has 4 slender, dorsomedial bristles, 

 the apical bristle long and conspicuous and with 2 con- 

 spicuous, exceptionally long, stout, lateral bristles at 

 the basal and apical third and 3 equally long, more 

 slender, curved ventral bristles. Middle femur with a 

 short, subapical, posterodorsal bristle, a similar, longer, 

 anterior bristle, and 1 anterodorsal, weaker counterpart ; 

 the ventral surface bears 7 or more long, black, basally 

 stout, attenuate, oblique, anterior bristles and 3 equally 

 long, stout, posteroventral bristles. These bristles are 

 from half to three-fifths as long as the tibia and there 

 are 4 or 5 additional long, slender, ventral, bristly hairs 

 and 3 or 4 shorter, posterodorsal bristles. 



Anterior femur with a weak bristle anterodoi-sally 

 near the apex and a ventral fringe of bristly hairs; its 

 tibia has 4 or 5 short, slender, dorsal and 4 long, basally 

 stout, posteroventral bristles. On the ventral surface 

 are 6 elements, the basal one no more than a hair, the 

 next 2 quite slender but longer, the next 3 long, and 

 basally stout. All tarsi end in slender, sharp claws, 

 well developed pulvilli and long, bladelike empodium. 



"Wings: The marginal cell closed with a moderately 

 long stalk; the anterior branch of the third vein ends 

 a short distance above the apex; the posterior branch 

 ends at least 4 times this distance to the rear; first pos- 

 terior cell not narrowed; the upper end vein of the 

 discal cell and of the fourth posterior cell is obliquely 

 offset by one-third the distance of the upper vein. 

 Fourth posterior cell closed with a moderately long 

 stalk; the anal cell likewise; the second basal cell ends 

 in 3 veins, the middle vein short with a thyridium above. 

 Alula as wide as the costal cell above; ambient vein 

 complete. 



Abdomen: The abdomen is comparatively short and 

 robust, not quite as wide as the mesonotum except pos- 

 teriorly; it is slightly wider distally and strongly 

 punctulate. Pile of abdomen moderately abundant, flat 

 appressed in both sexes, minute and setate. In the male 

 the pile is golden and slightly flattened. Sides of the 

 first tergite especially and scantily on the second and 

 third with some rather short, fine, erect hairs. There is 

 a vertical row of 5 or 6 long, but very slender, pale 

 bristles on the sides of the first tergite; remaining ter- 

 gites without trace of bristles. The males have seven 

 tergites and males also a little more slender, with nearly 

 parallel sides. In the females there are eight tergites 

 but both the seventh and eighth are quite short, the 

 seventh one-sixth as long as the sixth, slightly turned 

 down, the eighth a little shorter than the seventh, turned 

 ventrally down and in profile barely protruding beyond 

 the seventh. Terminal appendages short, broad and 

 narrow with a very minute, apical protrusion. Male 

 terminalia short and obtuse, protruding beyond the last 

 tergite. The male seventh tergite is extremely short 

 and liplike dorsally, about a twenty-fifth as long as the 

 sixth ; the sixth in turn is fully as long as the preceding 

 tero-ite. The sides of the seventh tergite are more ex- 



