ROBBER FLIES OF THE WORLD 



589 



Postmetacoxal area membranous; prosternum united 

 anteriorly to the lateral sclerite. 



Legs : All the femora are stout, especially the anterior 

 4, which are a little swollen dorsally and towards the 

 base on the anterior pair. Hind femur somewhat swol- 

 len on the outer half, especially in the male. The ven- 

 tral and posterior surfaces of the femora are largely 

 bare, but elsewhere the legs bear numerous, fine, ap- 

 pressed setae. Bristles are comparatively numerous 

 and stout on all the femora and on the hind tibia. The 

 hind femur bears 2 lateral bristles along the middle, 1 

 on either side dorsally at the subapex and a dorso- 

 medial bristle at the apex ; it also has 4 stout, ventro- 

 lateral bristles besides 1 basal and 1 longer, stout, 

 ventral bristle at the middle ; this femur has a ventro- 

 medial fringe of short, comparatively stout, medial 

 bristles. Hmd tibia with a stout, long, basal, dorso- 

 lateral bristle, another beyond the middle; it has an 

 equally conspicuous, dorsomedial bristle at the middle, 

 and 2 ventral bristles on the outer half. Hind basitarsus 

 as long as the next 3 segments. Middle femur with a 

 very stout, anterior bristle beyond the middle and 5 

 equally stout, ventrolateral bristles, 2 others ventrally 

 near the base. Middle tibia with 2 weak, posterodorsal 

 bristles, 1 anterodorsal on the apical fourth, 2 distal, 

 weak, short, posteroventral bristles, 2 long, distal, pos- 

 teroventral bristles and 2 still longer, stout, ventral 

 bristles. Anterior femur only with bristles venti-ally 

 on the basal half, included among these are 2 long, 

 striking bristles very stout at base and tuberculate, be- 

 sides several other less slender bristles. Anterior tibia 

 with an anterodorsal bristle at the base, 2 posterodorsal 

 bristles and 2 quite long, conspicuous, posteroventral 

 bristles. Claws stout, sharp, bent at the apex ; pulvilli 

 large ; the empodium stout with fine apex. 



Wings: The wings are yellowish brown with villi 

 on the outer fourth. The marginal cell is moderately 

 wide, the subcostal cell quite narrow. Marginal cell 

 is closed with a moderately long stalk, second submar- 

 ginal cell, as in Cinadus, is widened at the base, but the 

 posterior branch of the third vein is rather gently im- 

 dulate, perhaps a little more so in the male. Fourth 

 posterior cell and the anal cell closed and stalked. Alula 

 large and wide but distinctly narrowed at the base. 

 Ambient vein complete. 



Abdomen : The abdomen is rather slender and cov- 

 ered with scanty, coarse, flat appressed hairs, which 

 foi'm no marginal fringes, although there is a posterior 

 lateral row of scattered bristles, which become a little 

 stouter laterally, but conspicuous only in the females. In 

 the female the first segment has 3 or 4 very stout, lateral 

 bristles ; it has 4 on each side of the second segment and 

 2 long, stout bristles on each side of the remaining seg- 

 ments, besides the weaker, submedial bristles. Male 

 with eight tergites, the eighth tergite in the middle as 

 well as at the sides is half as long as the seventh. Fe- 

 male with seven tergites not included in the ovipositor. 

 Male terminalia distinctly small, much smaller than 

 in Cinadus, although of the same general type of or- 



ganization. The moderately elongate, superior forceps 

 are of about the same height apically as at base. The 

 apex is laterally sulcate but not deeply and the apical 

 portion is rather thick. The gonopod is long, with the 

 ventral cavity exposed ; the aedeagus and guides are ex- 

 posed but not at all prominent or long. Hypandrium 

 short but present. Female terminalia rather like Gina- 

 dus ; the eighth t«rgite is shaped the same but bears a 

 pair of long bristles laterally. It is more narrowed 

 apicaUy and the ninth and tenth segments are longer 

 but also deflected downward. Seventh sternite with 

 only fine and coarse hairs posteriorly. 



Distribution: Etliiopian: Cobalomyia fanovanensis 

 Bromley (1942). 



Genus Neomoctherus Oaten Saeken 

 FiGUEES 362, 789, 1475, 1484, 2309, 2311, 2395, 2398, 2426, 2427 



Moctherus Loew, Liimaea Entomologica, vol. 4, p. 58, 1849. 

 Type of genus: Moctherus paUipes Meigen, 1820. Desig- 

 nated by Coquillett, 1910, the fifth of 7 species. Preoccu- 

 pied by Coleoptera, 1846. 



Neomoctherus Osten Sacl^en, Catalogue of the described Dip- 

 tera of North America, ed. 2, Smithsonian Misc. Coll., vol. 

 16, pp. 82, 235, 1878. Change of name. 



Smaller than medium size and rather slender, atten- 

 uate flies. They are characterized by the short face 

 without a ventral gibbosity. The face has only a lim- 

 ited amount of stiff pile and a few, slender bristles near 

 the epistomal margin. In general these flies have a 

 rather bare appearance resulting from short though 

 dense pile. Bristles are particularly emphasized on the 

 abdominal stemites, where their strength and conspic- 

 uousness serve as the principal character separating 

 tliis genus from its congeners; strong bristles are also 

 generally present on the postmargins of the tergites. 

 The halves of the superior forceps have a tendency to 

 be broad, obtuse, with the apex turned abruptly inward 

 at a right angle so that the end of the terminalia is 

 often very blimt. Also the forceps tend to have a small, 

 apical lobe or process. Thus, two types are present, a 

 short, blunt form and a longer, less obtuse terminalia, 

 each with a process. Female terminalia strongly com- 

 pressed but only beginning on the outer half of the 

 eighth segment. Its nearest relative is Oerdistus Loew. 

 Length 15 to 20 mm. 



Head, lateral aspect : The face is not produced and 

 is scarcely visible on the upper half; the whole face 

 is nearly vertically plane, the lower portion of tlie face 

 being very slightly produced beyond the vertical plane; 

 it forms a low triangle due to the posterior recession of 

 the eye. The eye is anteriorly strongly convex, with the 

 posterior ventral fifth anteriorly recessive, the remain- 

 ing posterior margin plane in profile. The occiput is 

 moderately well developed and continued in the same 

 thickness to the vertex; pile of occiput fine and mod- 

 erately abundant through the middle both in front of 

 and behind the bristle-row ; there is a dense tuft of pile 

 behind the vertex on each side and the lower occipital 



