ASILINAB 



ROBBER FLIES OF THE WORLD 



451 



on the posterodorsal margin, including 1 quite close to 

 the apex. There is also present a double ventral row of 

 bristles: the posterior portion contains 9 stout, short, 

 black bristles ending basally in an additional cluster of 

 5 bristles ; in addition there is a stout, appressed cluster 

 of 6 or 7 longer, anterobasal bristles. The middle tibia 

 has short bristles, 3 ventral, 2 dorsal, and 4 posterior 

 bristles. The anterior femur bears a prominent, long, 

 posteroventral row of 7 or 8 bristles, 6 of which are 

 situated on the basal half ; the more distal members are 

 weak. Anterior tibia with 2 long and 1 or 2 short 

 posteroventral bristles and 4 weak, short, dorsobasal 

 bristles. Claws long^ sharp, slender, sharply bent down 

 at the apex; pulvilli long, thin, somewhat rounded at 

 the apex, nearly as long as claw; empodium three- 

 fourths as long as claw, bladelike. 



"Wings: The wings are long and comparatively 

 slender and smoky in the type of genus. The axillary 

 lobe is enlarged and there is an incisionary notch at the 

 end of the anal vein. The subcostal cell is narrow, the 

 stalk of the marginal cell long. The second sub- 

 marginal cell is short and wide, originating barely at 

 or beyond the end of the discal cell; it is greatly 

 widened both above and below the third vein, and the 

 lower branch of the third vein is midulate; since the 

 very short second posterior cell is greatly expanded 

 anteriorly these two veins greatly occlude the first 

 posterior cell in the middle. Anterior crossvein 

 strongly oblique entering the middle of the discal cell; 

 the lower end vein of the discal cell is very long indeed 

 and drawn backward and the upper end vein quite 

 short ; the fourth posterior cell is long and closed with 

 a long stalk ; second basal cell ends in two veins, anal 

 cell closed with a long stalk. Alula large, ambient vein 

 present throughout but weak over the middle posterior 

 border. 



Abdomen : At the base the abdomen is nearly as wide 

 as the mesonotum; the first tergite is strongly ridged 

 in the middle posteriorly, overlapping laterally or bulg- 

 ing and convex, somewhat creased anteriorly; it has 

 dense, rather matted, pale brownish yellow pile among 

 which posteriorly are 5 or 6 weak bristles. Second and 

 third tergites and others in decreasing extent with long, 

 dense, brownish yellow, lateral pile ; the actual margin 

 itself has a fringe of black hairs. Middle pile of ter- 

 gites not appressed. From the third tergite and be- 

 yond, the abdomen is gently and gradually tapered ; it 

 is wide in the male at the apex, strongly compressed 

 laterally in the female. Males with eight tergites, the 

 last two each half as long as the sixth tergite. Females 

 with seven tergites before the ovipositor. Male ter- 

 minalia large and conspicuous. Superior forceps high, 

 rather flattened laterally, broad, obtuse and winglike 

 at apex, the 2 balancers apposed, the proctiger erect be- 

 tween. Gonopod prominent but shorter ; hypandriiun 

 well developed. All parts bear much, long, coarse, 

 black pile, but the dorsal part of the gonopod has espe- 

 cially conspicuous, dense, black pile, as does the hypan- 

 drium. Female terminalia are large, elongate, shining 



black with the eighth tergite laterally compressed and 

 a little longer than the seventh tergite. The ninth ter- 

 gite and sternite are each of about the same length and 

 are short ; the sternite has stubby setae on its dorsal sur- 

 face. Tenth tergite slightly longer, cylindrical. Pile 

 of terminalia long, dense, bushy, fine and black. 



Distribution: Australian: Pararatus macrostylus 

 Loew (1874). 



Genus Neoaratus Ricardo 

 FiGUBES 366, 696, 710, 1616, 1623, 2226, 2250, 2415, 2428 



Arattis Wulp, Termfiszetrajzl Fuzetek, vol. 21, p. 236, 1898. 

 Type of genus: Asilus hercules Wiedemann, 1828, by origi- 

 nal designation. Preoccupied by Hymenoptera, 1896. 



Neoaratus Ricardo, Ann. Mag. Nat. Hist., ser. 8, vol. 11, p. 437, 

 1913. Change of name. 



Flies which are mediimi size and sometimes quite 

 large. They differ from Asilus Linne chiefly by the 

 relative position of the branches of the third vein. The 

 anterior branch ends at the apex of the wing, the pos- 

 terior branch ends a considerable distance behind. In 

 addition there are bristles on the sides of most of the 

 tergites. Length 18 to 40 mm. 



Head, lateral aspect: The head is rather long, due to 

 the well developed occiput and prominent gibbosity of 

 the face. The upper half of the face is moderately 

 long, and in some species the gibbosity is rather 

 abruptly developed dorsally ; in other species, due to its 

 lower and more inconspicuous character, it is gently 

 developed. The occiput is thick throughout, but espe- 

 cially below due to the posteroventral recession of the 

 eye. The pile of the occiput is dense over its whole sur- 

 face but in some species it is scanty on the upper half. 

 Slender bristles begin near the middle and at the vertex 

 in most species are 4 to 5 pairs of exceptionally stout 

 bristles which usually are of a contrasting color. The 

 proboscis is stout, especially on the basal tliird, where 

 it is swollen; it is gently tapered to the rounded and 

 slightly pointed apex ; the basal half below and laterally 

 bears numerous, long, coarse hairs, and the apex many 

 short, bristly hairs. Palpus large, long and cylindrical 

 with stout bristles at the apex and numerous, long, 

 bristly hairs over most of the surface. The antenna is 

 attached at the upper third of the head and the first 

 segment tends to be unusually elongate and generally 

 twice as long as the second. Both of these segments 

 have numerous, slender bristles ventrally along the 

 dorsal margin and fewer bristles laterally. The third 

 segment is sometimes as long as the first two combined, 

 in which case it is always slender. In other species it 

 is only IV2 times as long as the second segment and is 

 wide at the base and attenuate. There is a small micro- 

 segment followed by a style approximately as long 

 as the third segment. 



Head, anterior aspect : The head is not as wide as the 

 thorax and only a little wider than high. The face be- 

 low the antenna varies from about a fifth to a seventh 

 of the head width and is divergent below. Face, cheeks 



