ROBBER FLIES OF THE WORLD 



569 



they bear. Only the medial surface of the hind femur 

 and a small portion dorsally near the apex of the mid- 

 dle femur has appressed pile. Hind femur with 3 lat- 

 eral bristles of which only the last element at the outer 

 fifth is stout. At this same point there is an equally 

 stout, dorsolateral and ventrolateral bristle. Hind tibia 

 with 2 long, stout, dorsolateral bristles, both near the 

 middle ; there are some even longer, more slender dorso- 

 medial bristles and 2 shorter, stouter, ventral bristles 

 situated on the outer half. Middle femur with 1 stout 

 bristle posterodorsally near the apex. Middle tibia 

 with 2 quite long, stout, anterodorsal bristles close to 

 the middle, with 3 or 4 weak posterodorsal bristles, 

 sometimes rather stout, and with a single long, stout, 

 posterior bristle at the basal third, besides 1 ventrally 

 and distally. Anterior femur with only the numerous, 

 dense, long hairs characteristic of all the legs. Anterior 

 femur with 3 or 4 moderately long, posterodorsal bris- 

 tles and a single, long, stout posterior bristle at the 

 apical fifth. Anterior basitarsus a little longer than the 

 next two segments. Claws stout, sharp, bent at apex ; 

 pulvillus large, wide; the empodium long and blade- 

 like. 



Wings : The wings are tinged with brown ; marginal 

 cell closed with a comparatively short stalk. The sec- 

 ond submarginal cell begins beyond the end of the 

 discal cell and is basally widened above and below the 

 third vein. Second posterior cell anteriorly expanded 

 at base. Fourth posterior cell closed with a long stalk. 

 Anal cell closed. Posterior crossvein absent. The an- 

 terior and posterior branches of the third vein end 

 sliortly above and below the apex of the wing. Alula 

 large ; ambient vein complete. 



Abdomen : The base of the abdomen is nearly as wide 

 as mesonotum in the males and even wider in the fe- 

 males. First segment much wider than the second. 

 The abdomen is covered with short, appressed hairs 

 narrowly down the middle of the tergites, rapidly 

 changing to dense, very long, erect, coarse pile laterally ; 

 posteriorly and next to the wide pollinose margin this 

 pile is even more stout but scarcely forms bristles. 

 Among the nimierous hairs on the side of the first seg- 

 ment are 4 very long, quite slender bristles. Males with 

 eight tergites; the eighth visible only laterally, or at 

 least only linearly above. The seventh tergite is about 

 half as long as the sixth, the sixth half as long as the 

 fifth. Females with eight segments, not incorporated 

 in the ovipositor. Male terminalia unusually large, 

 wide and high. The superior forceps are broad and 

 thin distally with a quite deep, dorsal cleft. The proc- 

 tiger turns upward or even backward. The gonopod 

 is the largest element, bowl-shaped below, the halves 

 meeting below and with a strong gap between the 

 forceps. Hypandrium large. Females with the sixth, 

 seventh, and eighth tergites progressively compressed 

 laterally. While the eighth is still wide, it is perhaps 

 even higher than wide. Ninth and tenth segments quite 

 short ; the eighth tergite bears nmnerous, long, slender 

 bristles along the posterior margin. The eighth sternite 

 bears a patch of such bristles on each side and the 



whole posterior border of the seventh sternite has even 

 more conspicuous bristles. 



Distribution: Neotropical. Lesto-phonax mallopho- 

 roides, new species. 



Lestophonax malloplwroides, new epecies 



Length 15 mm. Male, female. Head: The head is 

 black ; face very thinly dusted with greyish white micro- 

 pubescence on the sides of the pronounced gibbosity. 

 Upper lateral margins of face with a wedge-shaped, 

 vertical stripe of appressed, coarse, yellowish micro- 

 pubescence, leaving the upper middle face black. Front 

 opaque black with black pollen. Pile of front, vertex, 

 antenna, and of the face black ; bristles of face very nu- 

 merous, long and slender and black, except that in the 

 middle ventrally above the epistomal margin there is 

 a small cluster of long, yellow bristles enclosed by the 

 black bristles. These pale bristles range m number 

 from 10 to about 20. The ventral pile of the occiput is 

 quite dense, long, and pale yellow. Proboscis with a 

 tuft of black bristles ventrally in the middle but with 

 short, yellow hairs at the apex and long, yellow hairs at 

 the base below. Ujiper bristles of the occiput black and 

 spinous. Some of the lower elements turned down- 

 ward. Antenna, proboscis and palpus quite black, the 

 latter has numerous, long, black hairs at the apex. Mid- 

 dle width of the third antennal segment a little more 

 than ll^ times the basal width. Style and the very 

 short microsegment not as long as the tliird segment. 



Thorax: The thorax is black, thinly pollinose and 

 mostly opaque or feebly shining. There is a slight 

 greenish reflection from the thorax and pleuron. Down 

 the mesonotum is a very narrow stripe of pale, brownish 

 white pollen anteriorly, becoming greyish white pos- 

 teriorly. From an oblique, posterior view there is a 

 wider, submedial stripe of pale, greyish white pollen, 

 which ends at the transverse suture, is continued nar- 

 rowly along the suture to the sides and anteriorly 

 widens out to include the whole area between and be- 

 hind the humerus. Posteromedial comer of the hu- 

 merus with brown pollen, the remainder with grey 

 pollen. Scutellum thinly, grey pollinose with numer- 

 ous, exceptionally long, slender bristles and bristly 

 hairs on the disc; the margin with 5 pairs of still 

 longer, slender, black bristles. All scutellar pile and 

 bristles black except for 2 yellow hairs on each side. 

 Rim of scutellum impressed, the grey pollinose meta- 

 notal callosities with abmidant, yellow pile. Lower and 

 middle propleuron densely yellow pilose, upper pos- 

 terior propleuron black pilose behind, yellow pilose in 

 front, the dorsal collar yellow pilose. Pteropleuron 

 pollinose but with central black spot with changeable, 

 pale pollen and bearing a large tuft of about 25 ex- 

 tremely long, slender, black bristles. Metapleural bris- 

 tles loose, numerous, very long, black and covering a 

 triangular patch. Hypopleuron with 4 long, black 

 bristles above, more numerous yellow ones below. 



Legs : The femora are relatively slender. Pile of the 

 legs exceptionally long, erect and rather dense, except 



