LAPHEIINAB 



ROBBER FLIES OF THE WORLD 



363 



palpus on either side of the proboscis base is a patch of 

 8 to 10 quite stout bristles; no pore present. 



Antenna attached at the upper fourth of the head, 

 of medium length ; the first two segments are short, the 

 first is twice as long as the second, unusually robust 

 and swollen chiefly ventrally; the second segment is 

 quite short. The third segment is V/ 2 times as long as 

 the first two combined, strongly swollen beyond the 

 basal third, which is attenuate, rather slightly nar- 

 rowed on the apical fourth dorsally, but strongly nar- 

 rowed from below. This segment is obliquely truncate 

 at the apex from a dorsal aspect; the apical pit carries 

 a concealed spine. 



Head, anterior aspect: Face below antenna a third 

 the head width and slightly divergent below ; subepis- 

 tomal area rather large, strongly oblique and concave, 

 concealed by the lateral bristles and mystax and the 

 long palpus. Face unusually densely covered with 

 coarse, opaque, whitish pile, matted and directed ob- 

 liquely downward from beneath the antenna to the 

 epistoma and continued to the eye margins and down 

 the upper lateral half of the subepistoma. Pile on the 

 upper face about half the length of that upon the lower 

 face and narrowly in front of the epistomal margin 

 the pile gives way to slender bristles of the same color. 

 Front exceptionally short with a tuft of short, bristly 

 hairs on each side in front of the ocellus and with the 

 lateral margin on the outer third densely beset with 

 short, appressed bristles. Vertex deeply excavated, 

 wide with slanting sides, the ocellarium small, low and 

 bearing minute ocelli ; across the middle there is a sin- 

 gle pair of quite stout, moderately long, divergent bris- 

 tles together with some shorter, bristly hair. Anterior 

 eye facets strongly enlarged. 



Thorax: The pleuron is everywhere densely, mi- 

 nutely appressed pubescent ; the mesonotum is bare, ex- 

 cept in front of and on the humerus and narrowly 

 along the sides. Pile of mesonotum rather dense, 

 bristly, quite flat appressed, moderately long, opaque, 

 and pale in color. Acrostical elements are not differ- 

 entiated from the surrounding pile. Dorsocentral 

 bristles differentiated only behind the suture where 

 there are 5 or 6 pairs of quite slender, moderately long 

 bristles, not always present. Humerus with numerous, 

 erect, bristly hairs and perhaps with a few quite weak 

 bristles depending on interpretation. In the type of 

 genus the following complement of moderately long 

 and stout, pale, lateral bristles is present: 2 noto- 

 pleural ; 3 supraalar ; 1 or 2 postsupraalar ; 2 postalar 

 with additional short, bristly pile. There are 6 pairs 

 of scutellar bristles, and also an irregular, submarginal 

 band of similar, stout bristles and additional long, stiff, 

 bristly pile. This pile is absent on the basal half. The 

 basal half of the scutellum is flat, the whole scutellum 

 quite thick with a rather slanting margin. 



Propleuron with a dense, ventral tuft of long, stiff 

 pile, the pronotum has an irregular band of similar, 

 shorter pile and 6 pairs of moderate bristles. Post- 

 lateral pronotum with slender bristles and abundant, 

 dense, short, bristly pile. The whole upper half of the 



mesopleuron only, the anterior and posterodorsal ster- 

 nopleuron bear dense short bristles or bristly pile. 

 Upper posterior corners of the mesopleuron with at 

 least 2 exceptionally stout, rather short, pale bristles; 

 all thoracic, leg, and abdominal bristles pale. Ptero- 

 pleuron with some bristly pile; posthypopleuron with 

 3 or 4 long, erect, slender bristles and some more 

 slender hairs. Metapleuron with a wide, oval patch of 

 numerous, moderately stout bristles and bristly pile. 

 Lateral slopes of the metanotum micropubescent only. 

 Posterior lateral metasternum with abundant long, fine 

 pile; ventral metasternum wide, chitinized, pubescent, 

 but with only a few scattered, short, appressed hairs. 

 Postmetacoxal area wide, short and distinctly mem- 

 branous. Tegula with a fringe of short, stout setae or 

 as many as 15 short, appressed bristles. 



Legs: The femora are unusually stout and distinctly 

 though rather moderately swollen to an equal extent on 

 all pairs ; most of the swelling contributed by the dorsal 

 half; all surfaces on all the femora densely, flat ap- 

 pressed pilose; the pile is coarse, bristly, whitish, and 

 opaque. In the type of genus the following comple- 

 ment of quite stout, rather short bristles is present : 7 

 ventrolateral on the hind femur; 3 dorsolateral bristles 

 lying over the part of greatest swelling, with 3 similar 

 dorsomedial and between them a single dorsal bristle ; 

 at the subapex medially a vertical row of 3 or 4 bristles, 

 and medially and proximal to these 5 or 6 more slender 

 bristles; there are also 4 or 5 ventral bristles. Hind 

 tibia with a dorsomedial row of bristly hairs only, but 

 with a dorsolateral and ventrolateral row of stout 

 bristles, 6 in the former, 3 in the latter; ventral sur- 

 face with a number of long, erect, bristly hairs on both 

 sides; apical circlet of 6 bristles. Middle femur with 6 

 posterodorsal, 6 dorsal, both groups quite short and at 

 the subapex a close-set group of 3 long, stout, postero- 

 dorsal bristles; anterior surface with 2 or 3 long, stout 

 elements and ventral surface with 8 or more similar 

 ventral bristles. Middle tibia with 6 anterodorsal, 7 

 posterodorsal, 7 posteroventral. 6 ventral bristles, the 

 more distal ones longer, and at least 2 long, stout, api- 

 cal, anteroventral bristles. 



Anterior femur with 9 dorsal, the last 3 subapical and 

 transverse, and with 2 posterodorsal bristles, 1 at the 

 base and 1 at the outer third. Anterior tibia with 9 

 exceptionally stout, short, anterodorsal and 8 similar 

 posterodorsal, besides 10 similar posteroventral bristles ; 

 below are 6 long, posteroventral bristles; ventral mar- 

 gin with 8 long, bristly hairs ; apex without spine. All 

 tarsi are short, all basitarsi unusually robust and a little 

 longer than the next three segments. Claws are thick 

 and unusually blunt; pulvilli long; the empodium long 

 and exceptionally bladelike, extending beyond the 

 claws. 



"Wings: The marginal cell closed with a short stalk; 

 anterior branch of the third vein ends well above the 

 wing apex; posterior branch ends far behind. First 

 posterior cell uniformly narrow, closed with a rather 

 long stalk. Upper end vein of the discal cell long and 

 strongly oblique; discal cell long and narrow, concave 



