DASTPOGONINAE 



ROBBER FLIES OF THE WORLD 



183 



crossveins in this cell. Abdomen more or less com- 

 pressed laterally. Length 16 mm. 



Head, lateral aspect : The head is unusually long ; face 

 strongly produced as a rounded, dome-shaped con- 

 vexity extending from the antenna to the epistoma. 

 The eye is narrowed below and moderately recessive 

 anteroventrally beginning above the middle. The oc- 

 ciput is extremely thick and prominent but slopes 

 gently away from the eye toward the medial plane. 

 It is obliterated narrowly near the vertex. The occipi- 

 tal pile is exceptionally long, fine and dense; bristles 

 are absent. The proboscis is of medium size, subcylin- 

 drical, with blunt apex very slightly tapered above and 

 below, the base slightly swollen, the dorsomedial ridge 

 low. It is directed obliquely downward, the apex bears 

 a number of fine hairs, and there are numerous, very 

 long hairs on the basal half of the ventral surface. 

 Palpus clearly of two segments, L-shaped, the first seg- 

 ment excavated, the second not porate, pubescent dor- 

 sally and with a few, long, stiff hairs. The antenna is 

 attached to the upper third ; the first segment is slightly 

 longer than the second and both bear long, fine hairs 

 ventrally and a few long hairs at the apex of the second 

 segment. Third segment as long as the head and very 

 slender; first two segments of equal length, with nu- 

 merous, very long, coarse hairs directed obliquely out- 

 ward. Third antennal segment longer than the first 

 two combined, much more slender, and with two micro- 

 segments. The first is very short, the second three 

 times as long, with spine at apex and both held ob- 

 liquely downward. 



Head, anterior aspect : The face below antenna is less 

 than one-third of the head width and divergent below. 

 Subepistomal area oblique, concave and micropubescent. 

 The face is micropubescent and, except for a narrow 

 lateral strip along the eye from the antenna is of de- 

 creasing width below, the face is everywhere covered 

 with numerous, very long, fine, stiff hairs, none of 

 which might be called bristles. The front is rather 

 strongly divergent to the vertex. On either side the 

 front is covered with numerous, long, stiff hairs. Ver- 

 tex moderately excavated, its sides slanting, the ocellar 

 protuberance large, with large ocelli and bearing nu- 

 merous very long, slender hairs. Central eye facets 

 strongly enlarged. 



Thorax: The mesonotum and pleuron densely polli- 

 nose. The mesonotal pile is abundant, very long and 

 rather fine but nowhere obscures the groimd color. 

 Acrostical and dorsocentral elements are present. Hu- 

 merus pilose; bristles absent. On the scutellum the 

 margin and surface as well have numerous, extremely 

 long, stiff hairs. The pleuron is characterized by 

 large, exceptionally dense tufts of long, fine, bushy pile 

 from several areas, with bristles absent. All portions 

 of the propleuron and collar with dense tufts of pile; 

 there is a large, dense tuft of pile on the upper third 

 of the mesopleuron. Metapleuron with its whole cen- 

 tral area occupied by a large, radiated tuft of fine pile. 

 Pteropleuron and hypopleuron without pile or at most 

 with a few minute hairs. Hypopleuron with a large 



535914— 62— pt. 1 13 



patch spot of micropubescence. Metanotal slopes 

 micropubescent only; metasternum with short but 

 abundant pile laterally and long pile ventrally. Post- 

 metacoxal area membranous; tegula pubescent only. 



Legs: The legs are stout without being especially 

 thickened, the femora without bristles but thickly cov- 

 ered with long, fine, wavy pde, and in some areas with 

 especially dense tufts or mats of pile. Hind femur 

 with matted, pale pile dorsolaterally on the outer half 

 and laterally below it with dense black pile. Medial 

 surface of hind tibia with unusually dense, oblique, 

 fine pile without setae. These tibiae bear the 8 lateral 

 and 8 to 10 ventral bristles: all rather slender, curved 

 and oblique; the apex has 1 dorsal, 3 lateral, 4 ventral, 

 and 2 medial. Middle femur with dense linear mats 

 of pile anteriorly and posteriorly and anteroapical 

 brush of dense pile; its tibia has exceedingly slender, 

 long, more or less appressed bristles as follows: 10 

 to 12 dorsal, 10 posterior, and 4 ventral bristles on the 

 outer half. Anterior femur with the cm-led tufted pile 

 emphasized posteriorly. This tibia has still more deli- 

 cate, stiff, bristly hairs, a dorsal row of 20, a posterior 

 row of 20 or more, and a ventral row of 10, of which 

 2 elements on the outer half are distinct bristles. 

 Tarsi end in sharp claws, well developed pulvilli, and a 

 long, basally swollen empodium. 



Wings: The wings are of normal width; marginal 

 cell is open; anterior branch of the third vein ends 

 slightly before the wing apex and begins some distance 

 from the end of the discal cell. Costal and subcostal 

 cells not narrowed. Discal cell large and wide, of 

 rather characteristic shape. Fourth posterior cell is 

 slightly narrowed, anal cell widely open. Second basal 

 cell ends in three veins, the middle vein quite short. 

 There is an extra crossvein between the third and 

 fourth veins situated near the end of the discal cell. In 

 both wings of Grypoctonus lama the second crossvein, 

 almost as close to the apex as the first one, is towards 

 the base. This extra crossvein is rarely missing but the 

 general venation is still characteristic. The anterior 

 crossvein is situated near the base of the discal cell. 

 Alula quite narrow or absent altogether; ambient vein 

 otherwise complete. 



Abdomen : The abdomen is robust and more or less 

 flattened across the tergites and shorter than the wing. 

 It is at least as wide as the mesonotum. Tergite one is 

 unswollen. Males with eight tergites, the eighth a little 

 reduced in length. Females with eight tergites, eighth 

 tergite is two-thirds to three-fourths as long as the 

 seventh, pile of abdomen long, shaggy and matted, 

 more abundant laterally, especially along the side mar- 

 gins but not obscuring the ground color. Bristles 

 absent. Sternal pile long, dense and matted. Male 

 terminalia comparatively short and obtuse and not 

 rotate. The epandrium is not only cleft but has a space 

 between nearly as wide as either lobe; proctiger short, 

 broad and notched with membrane. Gonopod promi- 

 nent, longer than the epandrium, well separated with a 

 space between on the distal half; it is not oblique. 

 Hypandrium quite short; cavity open, concealed by 



