ROBBER FLIES OF THE WORLD 



493 



mesopleuron and upper sternopleuron witli numerous, 

 long, stiff hairs; pteropleuron -with about 20 fine, long 

 hairs. Hypopleuron with a wide, vertical band of long, 

 stiff, white pile, and a patch spot of pubescence. Meta- 

 pleuron with a middle, vertical band of long, slender, 

 white bristles. Metanotal slopes bullose and micro- 

 pubescent only. Postmetacoxal area membranous. 



Legs: The femora are rather stout, especially the 

 anterior four. Hind femur everywhere flat appressed 

 pilose and with an apical circlet of 8 short, moderately 

 stout bristles, 4 laterally and 4 medially. There is a 

 dorsal pair of longer, subapical bristles. This femur 

 has 6 dorsolateral, 6 ventrolateral, 1 ventrobasal, 5 ven- 

 tromedial bristles, and 4 medial bristles, confined to the 

 basal third. Hind tibia slender, appressed pilose, with 

 6 dorsal, 5 or 6 dorsolateral, and 4 dorsoventral, mod- 

 erately long, stout, curved, oblique bristles, and a ven- 

 tral fringe of 12 to 15 long, fine hairs; it also has medi- 

 ally an appressed brush of brassy setae arising at the 

 middle and continued on to the tarsi. Middle femur 

 with 3 anterior bristles, 3 posterior near the middle, 4 

 posteriorly at the apex, 7 posteroventrally on the basal 

 half, and 5 anteroventral bristles through the middle. 

 The middle tibia bears, besides the ventral fringe of 

 fine, scattered hairs, 3 dorsal bristles, 2 anterodorsal, 

 4 longer posterior, 1 posteroventral and 1 ventral bris- 

 tle; apical circlet of 8 bristles. Anterior femur some- 

 what stouter, with long, stiff, white pile below and some 

 erect, white pile above, but no bristles. Tlie anterior 

 tibia bears a single bristle anteriorly near the base, 6 

 short, curved, oblique, stout bristles dorsally and 3 very 

 long, stout bristles posteriorly, among which is mixed a 

 fringe of equally long, stiff, white pile. Tarsi end with 

 long pulvilli and sharp claws; the empodium long. 



Wings: The wings are rather slender and hyaline; 

 marginal cell closed with stalk, both the anterior and 

 posterior branches of the third vein end well before the 

 wing apex ; the second submarginal cell is slightly nar- 

 rowed at apex. The fourth posterior cell is closed with 

 a long stalk, anal cell closed with a stalk; ambient vein 

 complete. The marginal cell is distinctly widened; 

 costa and costal cells not expanded. 



Abdomen: The abdomen is strongly tapered in fe- 

 males; only slightly tapered near the base in males. 

 Abdomen considerably longer than the wings, especially 

 in female. Stout, white bristles are present as follows: 

 6 pairs on the first tergite, 5 to 8 pairs posteriorly and 

 subapically, encircling the second and third tergites, 

 and similarly with reduced numbers on the remaining 

 tergites. Seven tergites are present in the male with 

 the eighth barely visible linearly. Tlie female has seven 

 tergites, with the eighth quite elongate, conical and in- 

 corporated in ovipositor. Male terminalia conspicuous, 

 elongate, not rotate. The superior forceps tightly ap- 

 posed ; gonopod short, the hypandrium deeply bilobed 

 in the middle with posteroventrally a dense, long, ap- 

 posed brush of stiff, bristly, white pile. Female ter- 

 minalia as wide dorsally as laterally, the apical portion 

 dorsally split and pointed ; spines absent. 



Distribution: Neotropical: Apotinocerus hrevistyl- 

 aiiwsWulp (1882). 



Genus Philonerax Bromley 



Figures 212, 689, 705, 750, 1439, 1448, 2225 



PhiloneracD Bromley, Diptera Patagonia and South Chile . . . 

 in the British Museum (Natural History), pt. 5, p. 270, 

 1932. Type of genus: Asilus mucidus Walker, 1837, by 

 original designation. 



Medium size asilids, belonging to the IVerax, new 

 genus, complex, in which the anterior branch of the 

 third vein ends before the wing tip. On the wing in 

 the male the costa is distmctly expanded. Most readily 

 distinguished from its allies in the females, in which 

 the terminalia are quite short and broad and slightly 

 depressed dorsoventrally. These flies are comparatively 

 narrow, the mesonotimi low, the female abdomen ta- 

 pered. The males are more robust with large, wide 

 termmalia. The face is strongly produced and gib- 

 bous, with an abrupt ledge just above the middle of 

 the face, the bristles quite strong. Length 15 to 22 mm. 



Head, lateral aspect : The face has a strong gibbosity 

 on the lower half, abruptly developed with a conspic- 

 uous ledge dorsally ; the ujiper half of the face is short. 

 Eye of medium length, strongly convex anteriorly, 

 nearly plane or at most very slightly convex pos- 

 teriorly; the eye is considerably more narrow on the 

 ventral half and it has a prominent, extensive, pos- 

 teroventral recession which mstead of bemg oblique 

 tends to be in the same plane as the upper occiput. The 

 occiput is moderately thick, more prominent below and 

 bears dense, fine pile which becomes progressively 

 longer until it is quite long ventrally; mixed with the 

 pile and beginning just below the middle of the head 

 are 8 pairs of short, stout, pale bristles. Near the upper 

 corners of the occiput there are 8 pairs of longer, black 

 bristles. Proboscis robust, subcylindrical with a very 

 bluntly rounded apex whicli carries stiff, numerous, 

 short hairs, both above and below. On the ventral sur- 

 face near the midline is a row of long, stiff, oblique 

 hairs extending to the outer third, and along the lateral 

 ventral margin on the basal half are some additional, 

 similar, long hairs ; ventral fissure confined to tlie outer 

 third ; medial dorsal ridge of medium height and con- 

 fined to the middle. Palpus rather slender and cylin- 

 drical, with numerous, long, stiff, white hairs, including 

 the apex. The antenna is attached at a level corre- 

 sponding to the middle of the eye. The anteima is rather 

 short, the third segment exceptionally short; the first 

 segment is a little longer than the second ; the style is 

 almost exactly as long as the combined length of all 

 three segments. Microsegments absent. Pile of the 

 first segment abundant, longer below and on the sides 

 and coarse ; second segment with 2 or 3 short, stiff hairs 

 below near the apex. 



Head, anterior aspect: The face below the antenna 

 is about one-fifth the head width and wider below. 



