DASTPOGONINAB 



ROBBER FLIES OF THE WORLD 



261 



a few, long, stiff hairs, the stiff apical hairs are longer 

 than usual and chiefly confined to the outer ventral fifth 

 and the apex. Palpus clearly of two segments, the first 

 segment is excavated and bears numerous, long, coarse, 

 ventral hairs; the second segment is robust, attenuate 

 basally and apically and microporate at the apex with- 

 out apical bristles but with numerous, coarse bristles on 

 all surfaces. The second palpal segment is attached a 

 short distance dorsally from the apex of the first 

 segment. 



The antenna is attached at the middle of the head but 

 is of only moderate length ; the first two segments are 

 quite short, beadlike, each somewhat swollen in the 

 middle. The third segment is elongate; not quite as 

 wide basally as the second segment and only slightly 

 narrowed or tapered distally. It is obliquely truncate 

 apically and carries two microsegments ; the first mi- 

 crosegment is obliquely truncate ventrally and the sec- 

 ond microsegment is longer and robust. The end mi- 

 crosegment bears a distinct, short, dorsal, apical spine. 

 The pile of the first antennal segment is composed of 

 slender bristles, unusually long dorsally and laterally 

 but still longer ventrally where they are longer than 

 the combined length of the first two segments. Second 

 segment dorsally with 6 or 7 bristles as long as those in 

 a similar position on the first segment ; the ventral as- 

 pect of this segment has 3 long, stiff bristles and some 

 more slender, bristly hairs which are as long as the third 

 segment excluding its microsegments. Third segment 

 with 2 or 3 short, stiff bristles dorsally. 



Head, anterior aspect: The face below the antenna 

 is one-fourth the head width and distinctly divergent 

 below. Subepistomal area rather small and horizontal, 

 concave and bare. The face is micropubescent and 

 apilose on the upper half; on the lower half it bears 

 an extremely dense, tectiform mat of slender, opaque 

 bristles which are directed obliquely downward; the 

 longer and medial elements reach to the tip of the pro- 

 boscis. Front long and wide, flat and pollinose, with a 

 submedial, elongate patch of stiff, somewhat appressed 

 bristles; the vertex is slightly but distinctly narrower 

 than the front and moderately excavated on each side. 

 The eyes rise distinctly above the vertex. Ocellarium 

 exceptionally large and broad with vertical sides; all 

 the ocelli are large, the anterior ocellus exceptionally 

 large. Between the ocelli on either side is a patch of 

 8 stiff, pale bristles and a similar patch of 5 or 6 on each 

 side behind the ocelli. Anterior eye facets strongly 

 enlarged and zoned. 



Thorax : The thorax is short, appressed micropubes- 

 cent. Pile of mesonotum dense but short, bristly and 

 curled backward ; it is distinctly longer across the an- 

 terior margin and laterally ; there is present a distinct 

 band of acrostical elements in 4 rows anteriorly, 2 of 

 these rows are over the middle area. The dorsocentral 

 elements are differentiated only a comparatively short 

 distance in front of the suture, where there are 3 pairs ; 

 behind the suture are 3 or 4 pairs of longer bristles. 

 Humerus short with abundant, bristly pile and nu- 

 merous, longer bristles. The following complement of 



bristles is present in the type of genus : 14 humeral, a 

 cluster of 6 posthumeral, a diagonal row of 3 excep- 

 tionally stout notopleural, a longitudinal row of 3 or 

 4 supraalar, 3 or 4 long, very stout postalar bristles, and 

 4 pairs of scutellar bristles. Scutellum pubescent, a 

 little thickened and slightly convex. Propleuron with 

 exceptionally dense, long, bushy pile including the dor- 

 sal portion; bristles absent. Anterior sternopleuron 

 with a small tuft of pile; posterior border of the meso- 

 pleuron with numerous, stiff hairs, the upper sterno- 

 pleuron with only 2 or 3; pteropleuron and hypo- 

 pleuron apilose; metapleuron with a wide, vertical 

 band of many, long, slender, bristly hairs; metanotal 

 slopes micropubescent only; lateral metasternum 

 densely pilose posteriorly; the ventral metasternum 

 is narrow but heavily chitinized, polished, with a few 

 long hairs from the membranous area immediately an- 

 terior to it ; it appears to be separated from the post- 

 coxal area by a deep transverse depression. Postcoxal 

 area membranous and extensive; tegula with several 

 stiff setae. 



Legs: All the femora are distinctly swollen; the 

 anterior and middle pairs are swollen except close 

 to the apex, the hind pair is plane ventrally with all of 

 the swelling dorsal, leaving the base and the apex 

 slightly narrowed. The pile of the femora is coarse, 

 flat appressed and setate throughout, except ventrally. 

 The ventral surface of the hind femur has a wide, 

 conspicuous tuft of long, but more or less appressed, 

 dense, coarse pile basoventrally which extends to the 

 middle of this femur or a little beyond. The following 

 complement of stout, mostly long bristles present: 5 

 lateral and 2 dorsolateral on the apical fourth, 2 dorsal 

 somewhat closer to the apex and a corresponding dorso- 

 medial, 2 or 3 weak, slender ventrolateral in the middle. 

 The trochanter has 6 or 8 exceptionally stout bristles, 

 the coxa with stiff hairs. Hind tibia somewhat dilated 

 at the apex and a little narrowed subapically with 4 

 long, quite stout, dorsomedial, 3 similar dorsolateral 

 on the basal half, and 6 ventrolateral elements distrib- 

 uted over the middle half; all these elements are 

 oblique, the first 2 smaller and paler, the last 4 black 

 and so stout as to be spinelike and tuberculate. A brush 

 of ventral setae is confined to the outer fourth, more 

 extensive medially. Apex with 2 spinelike, ventral 

 bristles, and 1 lateral, 2 weak medial, and 1 weak 

 dorsal bristles. Basitarsus nearly as long as the suc- 

 ceeding three segments. 



Middle femur with 1 slender bristle anterodorsally 

 near the apex and 2 dorsal and 2 posterodorsal, both 

 stout, on the apical third. This tibia has 3 anterodorsal, 

 4 posterodorsal, 7 posteroventral bristles short and very 

 stout, and 3 long, very stout ventral bristles. Anterior 

 femur with 3 stout bristles anteroventrally and clus- 

 tered in the middle ; 2 stout, posterodorsal elements on 

 the outer third; this tibia has 6 or 7 anterodorsal, 3 pos- 

 terodorsal, 6 posteroventral, and 3 very stout ventral 

 bristles. The apex of the anterior tibia bears a stout, 

 curved spine and the basitarsus has a patch of denticles. 

 All tarsi end in stout, long, sharp, gently curved claws, 



