DASYrOGONINAE 



ROBBER FLIES OF THE WORLD 



69 



spicuous. Pile of abdomen short, fine and scanty with- 

 out bristles. Postmetasternum behind the posterior 

 coxa elongate and apparently entirely chitinized. 



Distribution: Ethiopian: Oxynoton francoisi Jans- 

 sens (1951). 



Genus Paroxynoton Janssens 



Figures 24, 417, 857, 866, 1663 



Paroxynoton Janssens, Bull. Inst. Scl. Nat. Belgique, vol. 29, 

 no. 42, p. 11, 1953. Type of genus : Paroxynoton tigrinum 

 Janssens, 1953, by original designation. 



Small, humpbacked flies distinguished from Rhipi- 

 docephala Hermann by the shorter antenna, more 

 attenuate third antennal segment and the absence of a 

 dorsal spine near the middle of the plumose second 

 microsegment. Perhaps annectent with Hoplopogon 

 Engel. Length 7 mm. 



Head, lateral aspect: The head is short but quite 

 wide, the face scarcely visible in profile either above 

 or below. The occiput near the middle is swollen. 

 The proboscis is short, stout, cylindrical, the apex 

 strongly compressed laterally and truncate in profile. 

 The palpus is large, nearly as long as the proboscis, 

 cylindrical, with long, stout bristles apically and ap- 

 parently composed of only one segment; if two seg- 

 ments are present they are more or less fused. The 

 antenna is longer than the head ; the first two segments 

 are stout but short and beadlike. The third segment is 

 attenuate, and microsegments excluded, is nearly twice 

 the combined length of the basal segments; the third 

 segment bears a short, distinct microsegment, fol- 

 lowed by a much longer, stout, stylelike, plumose, 

 attenuate microsegment, which lacks a dorsal spine. 



Head, anterior aspect: The face is one- fourth the 

 head width, with nearly parallel sides and pubescent. 

 The lower face bears 12 to 15 long, weak, downturned, 

 bristly hairs; upper part of face without pile. The 

 vertex is very slightly wider than front or upper face. 

 The ocellar protuberance is moderately high and rather 

 abrupt, with only short, weak hairs. The head is 

 deeply excavated above and the occiput at the vertex 

 is anteromedially excavated, leaving the posterior eye 

 margin oblique from the dorsal aspect. The ocellarium 

 and very large anterior ocellus are set far forward, 

 facing anteriorly. Eyes flattened anteriorly, the 

 central facets unusually enlarged. 



Thorax : The mesonotum is short, quite high, and in 

 profile forming almost a hemicircle, being equally steep 

 anteriorly and posteriorly. The entire mesonotum has 

 erect, abundant pile which becomes even more dense 

 on the posterior half of the mesonotum and more than 

 twice as long as the anterior pile. Humerus pubescent, 

 with a few scattered hairs; posterior part of mesono- 

 tum and the sides rather coarsely pubescent and the 

 middle anterior portion pollinose. Scutellum like the 

 mesonotum very densely micropubescent ; the disc with 



a few, fine hairs. There seem to be no pleural bristles 

 but there is a single, quite long, extremely delicate, 

 slender, bristly hair at the anterior corner of the post- 

 callosity, another on the upper mesopleuron, none on 

 the margin of the scutellum. Mesopleuron with some 

 fine, erect pile and the metapleuron with a long, 

 vertical fanlike fringe of 6 or 7 bristly hairs. 



Legs: The hind femur relatively short but consid- 

 erably longer than the anterior 4 femora. Pile dense, 

 appressed, the ventral surface with a fringe of 6 quite 

 long, erect, bristly hairs; the ventrolateral surface has 

 3 long, rather stiff, yellow bristles beyond the middle 

 and 2 much shorter, finer bristles before the middle. 

 There are no bristles dorsally at the apex. Hind tibia 

 with coarse, matted, appressed, long, pale pile and bris- 

 tles as follows : dorsal surface with 6 or 7 minute bris- 

 tles, lateral surface with 3 quite long, stout bristles, 

 ventral surface with 3 bristles, the distal bristle sub- 

 lateral; apex with 1 short dorsomedial, 1 long dorso- 

 lateral, and 2 or 3 ventral bristles. Middle femora with 

 1 minute, posteroapical bristle, the ventral margin 

 with 5 or 6 long, slender bristles. The tibia has accentu- 

 ated dorsal and ventral bristles in its ventral plane; 

 they slightly curve forward ; there are 5 dorsal bristles, 

 the middle 3 quite long, stout, oblique, slightly curved; 

 the ventral surface with only 3 equally long bristles. 

 The apical bristles are included, except ventrally where 

 there is a cluster of 3 or more short bristles. Anterior 

 femur without bristles; its tibia has only moderately 

 long bristles behind, 5 in number, and 4 anterodorsal 

 bristles, these short and weak ; the apex below has 2 or 

 3 short bristles. The claws are moderately long, slen- 

 der and sharp, strongly curved at the apex ; the pulvilli 

 are four-fifths the length of the claw, the empodium 

 is reduced to scarcely more than a third the length of 

 the claw. 



Wings: The wings are broad, the marginal cell is 

 widely open; the second submarginal cell near the wing 

 margin is not or scarcely wider than the base of this cell. 

 All posterior cells are widely open and the anterior 

 crossvein enters the discal cell at or close to the middle 

 of that cell. Middle end vein of the second basal cell 

 quite long; anal cell open; alula small but distinct; 

 ambient vein complete. 



Abdomen : The abdomen is more or less flattened at 

 the base and rather wide, tapering posteriorly. Sides of 

 the first tergite with weak pile. The middle of the ter- 

 gites appear to be soft and membranous as in HoJco- 

 cephala Jaennicke. They are wrinkled, drawn together 

 and creased down the middle and the tergites at least be- 

 yond the second segment seem to be reduced to lateral 

 quadrate plates bearing pubescence throughout and 

 with stiff, subappressed pile laterally. The female 

 terminalia consist of two very small, short, unmodified, 

 protrusive, dorsal and ventral lobes. 



No males were seen. 



Distribution : Ethiopian : Paroxynoton tigrinum 

 Janssens (1953). 



