ROBBER FLIES OF THE WORLD 



473 



to 12 quite short, bristly hairs along the eye margin. 

 Vertex rather deeply excavated but unusually narrow 

 and with vertical sides; tlie comparatively low and 

 small ocellarium is set anteriorly with vertical sides 

 and bears 2 or 3 pairs of short, bristly hairs which are 

 curled anteriorly forward. Anterior eye facets but 

 little enlarged. 



Thorax : The thorax is poUinose ; the pile of the mes- 

 onotum is extremely short, scanty and bristly. There 

 in a single row of acrostical setae equally short, and 

 minute; dorsocentral setae are present in 1 or 2 rows, 

 and also short but there are 4 or 5 long, slender, bristly 

 hairs posteriorly in each row. In the type of genus 

 the lateral bristles consist of 2 weak humeral, 3 stout 

 but rather short notopleural, 2 supraalar, 2 supraposta- 

 lar, 3 or 4 postalar bristles and 6 pairs of slender, rather 

 short, scutellar bristles. The scut«llum is moderately 

 thick and convex and poUinose, with impressed rim. 

 Propleuron with abundant, fine, long pile ; bristles are 

 limited to the pronotum where there are only 5 pairs. 

 The upper border of the mesopleuron has numerous, 

 stiff, bristly hairs but no bristles. Anterior and upper 

 middle stemopleuron and a vertical band on the ptero- 

 pleuron with some bristly hairs, at least 8 or 10 in 

 each area. Posthypopleuron with a vertical row of i 

 slender bristles and other equally long, bristly hairs. 

 Metapleuron with a single row of 5 stout, rather long 

 bristles and dorsally with numerous, slender, bristly 

 hairs. Lateral slopes of the metanotum strongly bul- 

 lose, creased ventromedially and densely poUinose : only 

 the posterior lateral metastemum and the ventral met- 

 astemum bear long pile. Postmetacoxal area mem- 

 branous; tegula with setae; posterior basalare with 4 

 rather stiff, moderately long bristles. 



Legs : The femora are only moderately stout ; this is 

 especially true of the posterior pair. The anterior 4 are 

 slightly thickened towards the base but only doreally. 

 Pile of the hind femur dense, short, appressed and 

 setate. Bristles are numerous, quite stout, all black, 

 and of only moderate length. The following comple- 

 ment of bristles is present on the hind femora in the 

 type of genus : 4 lateral, 1 subapical dorsolateral and 1 

 dorsomedial, 5 ventrolateral, an apical vertical row of 

 5 medial bristles, and 4 ventromedial bristles. This 

 tibia has 2 dorsomedial bristles confined to the basal 

 half, 2 dorsolateral which are also basal, and 2 ventro- 

 lateral bristles on the outer half. The tibial pile is 

 dense, short, appressed with a brush of orange brown 

 setae on the entire medial surface; the apex bears 1 

 ventromedial, 1 dorsomedial, 4 ventral, 1 lateral and 1 

 dorsolateral bristle. IMiddle femur with 5 anterior 

 bristles, the more distal ones doubled ; 5 ventrolateral ; 

 9 ventral ; and 3 posterior bristles. This tibia has 2 an- 

 terodorsal bristles, 2 posterodorsal, 2 posterior and 3 

 posteroventral bristles besides 2 stout, ventral bristles. 

 Anterior femur with 5 exceptionally stout, ventral 

 bristles on the basal half ; anterior tibia with a single, 

 basal, anterodorsal bristle and 3 or 4 posterodorsal ele- 

 ments besides 3 quite slender, but long posteroventral 



bristles. Anterior basitarsus quite short; twice as long 

 as wide and not as long as the two succeeding segments 

 together. Posterior basitarsus nearly as long as the 

 succeeding three segments. Tarsi end in stout, bluntly 

 pointed claws, curved from the base, long wide pulvilli, 

 and long, bladelike empodium. 



Wings: The wings are wider on the basal third. 

 Marginal cell closed almost at the margin, the stalk 

 extremely short; subcostal cell narrow; the anterior 

 branch of the third vein ends distinctly above the wing 

 apex, the posterior branch ends far to the rear of the 

 apex. The second submarginal cell is quite narrow on 

 the basal two-thirds, strongly flared distally, and takes 

 origin opposite the end of the discal cell ; it has a long, 

 basal spur near its origin which leaves the base of the 

 anterior branch of third vein simulating a straight, 

 oblique crossvein. The anterior crossvein enters the 

 discal cell before the middle; the fourth posterior cell 

 closed with a moderately long stalk, its anterior and 

 distal surface convex, its posterior surface plane. The 

 lower end vein of the discal cell is a little longer than 

 the upper vein and rectangular to it. Second basal cell 

 ends in tliree veins, the middle vein nearly eliminated. 

 Anal cell closed with a rather long stalk; alula large, 

 ambient vein complete. 



Abdomen : The abdomen is robust and almost as wide 

 as the mesonotum. The sides of the first tergite are 

 strongly protuberant. Pile of the abdomen short and 

 largely appressed across the middle of the tergites, be- 

 coming longer, coarse and subappressed laterally, with 

 a tendency for the pile on the middle of the sides to be 

 directed outward in the form of matted brushes. Bris- 

 tles absent, except on the first tergite, where there are 8 

 pairs. First sternite with a few, minute setae laterally ; 

 remaining sternites with long, erect, bristly pile. Male 

 with eight tergites, but the eighth quite short. Male 

 terminalia quite large, dominated by the long, obtuse 

 superior forceps, which bear a small dorsoapical notch. 

 Proctiger small but directed obliquely upward. The 

 gonopod is large and prominent laterally, but only half 

 as long as the superior forceps. Hypandrium large and 

 obtuse. No females seen. 



Distribution: Oriental: Anacinaces gigas Enderlein 

 (1914) ; ruiiventrisTsia,cq\\a.Tt (1838). 



IMost if not all those Oriental species placed by early 

 dipterists in the genus Erax Scopoli belong here also. 



Genus Eicherax Bigot 



FiGiiEES 322, 375, 697, 742, 743, 1419, 1428, 1627, 1628, 2252, 

 2384, 2401 



EicheroT Bigot, Ann. Soc. Ent. France, ser. 3, vol. 5, p. 545, 

 1857. Type of genus: Erax simplex Macquart, 1848, by- 

 original designation. 



Eristicus Loew, Linnaea Entomologiea, vol. 3, p. 396, 1848. 

 Preoccupied by Hymenoptera, 1845. Type of genus : 

 Eristicus nigripes Bellardi, 1861, by present designation. 



Xeoeristiciis Osten Sacken, Catalogue of the described Diptera 

 of North America, ed. 2, Smithsonian Misc. Coll., vol. 16, 

 pp. 81, 235, 1878. Change of name. 



