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XINITED STATES NATIONAL MUSEUM BULLETIN 224 



and the very large, oblique epistoma pubescent; the 

 cheeks are quite prominent. The upper portion of the 

 face generally without pile, sometimes with a few setae 

 along the eye margin. The facial gibbosity, whether 

 low or prominent, contains numerous, long, slender 

 bristles and bristly hairs on the upper portion ; also on 

 a medial triangular area which rests on the epistoma it 

 contains many, long, stout bristles which extend down 

 the sides of the subepistoma. Front short, poUinose, 

 with an anterior, sxmken, shallow groove and bearing 

 a subocular patch and medial to it a sublateral patch of 

 numerous, rather stout bristles and bristly hairs. The 

 front is a little widened, the vertex distinctly narrow 

 and rather deeply excavated. The ocellarium is large, 

 sometimes without bristly pile between the ocelli, but 

 more generally with 2 to 6 pairs of bristles located 

 there and a like number of pairs behind the ocelli. 



Thorax : The thorax is moderately high but long and 

 arched anteriorly and posteriorly ; it is pollinose, with 

 numerous, suberect setae. In some species the acrostical 

 bristles are developed into a distinctly isolated double 

 row but in the type of genus not so. Humerus with 

 bristly pile; there are well developed dorsocentral ele- 

 ments differentiated, beginning a short distance behind 

 the humerus, with a prominent, bare, submedial stripe 

 in most species. The posterior dorsocentral elements are 

 longer. The lateral complement of bristles contain 1 

 often weak posthumeral, 2 or 3 notopleural, 2 to 4 

 supraalar, at least 2 suprapostalar, 3 postalar, and on the 

 scutellum 1 to 3 pairs of bristles; in the type of the 

 genus the scutellum has no bristles and only a row of 

 numerous, fine, long, bristly hairs, and a considerable 

 number of hairs on the disc. In other species there are 

 only a very few hairs on the disc. Scutellum moder- 

 ately thick and convex with a distinct impressed rijn. 

 The pronotum may have 3 or 4 pairs of slender bristles, 

 as many stout ones, or may have only long pile. Upper 

 and posterior borders of the mesopleuron with a narrow 

 band of hairs or sometimes with rather numerous, 

 slender bristles, together with similar elements along 

 the upper sternopleuron, the upper pteropleuron, pos- 

 terior hypopleuron and with a double irregular row of 

 long, slender bristles on the metapleuron. Posterior 

 basalare with bristly pile and the metanotal callosity 

 with similar pile. Metasternum pilose; postmetacoxal 

 area membranous, the prosternvmi dissociated. 



Legs: The femora are stout; only the first 4 are a 

 little swollen. The pile is abundant but unusually fuie, 

 subappressed and on the tibiae somewhat more setate. 

 Bristles are exceptionally numerous, stout and con- 

 spicuous in the type of genus, but somewhat less 

 numerous in other species. Tlie type of genus bears the 

 following bristles: 5 medial bristles on the hind tro- 

 chanters and on the hind femur 3 lateral, 6 ventro- 

 lateral, and 4 ventromedial bristles. Dorsally at the 

 subapex of the hind femur there is a bristle on each side 

 and at the apex 1 lateral, and a medial row of 4 or 6 

 bristles. The liind tibia bears 3 dorsolateral, 4 dorsome- 

 dial and 4 ventrolateral bristles ; apex with 10 bristles. 

 Middle femur with 4 very stout, anterior bristles, 4 



equally prominent, anteroventral bristles, and 8 pos- 

 terior bristles ; its tibia bears, beginning at the middle, 

 4 dorsal, 4 posterior, 1 distal posteroventral, and 3 very 

 long, stout, ant«roventral bristles. Anterior femur with 

 3 stout, posterior bristles; its tibia has 1 stout, basal an- 

 terodorsal, and 4 shorter elements, 3 posterodorsal, and 

 2 long, posteroventral bristles. All surfaces of the 

 femora with conspicuous fringes of long, slender hairs. 

 All basitarsi comparatively short and robust; the first 

 basitarsus is long as the next 2 segments ; hind basi tarsus 

 as long as the next three. Claws stout, sharp, bent 

 chiefly at the apex ; pulvilli large ; the empodium blade- 

 like. 



Wings : In the male of the type of genus the costa is 

 bent outward and greatly thickened over the middle. 

 The marginal cell is very greatly widened and the first 

 three cells of the anterior border consjiicuously and reg- 

 ularly rippled. In females the marginal cell is moder- 

 ately widened and moderately and i-egularly rippled. 

 In other members of the genus this marked widening 

 and rij^pling is lacking. In the type of genus the ante- 

 rior branch of the third vein ends a little before the 

 wing apex but in other species it ends at the apex. In 

 any case, the posterior branch ends a considerable dis- 

 tance behind. The base of the fourth posterior cell is 

 abruptly widened to at least twice the width of the 

 discal cell, the base of the second submarginal cell arises 

 at a strong angle from a plane base formed by the third 

 vein. Fourth posterior cell closed and stalked and the 

 anal cell likewise. Ambient vein complete. 



Abdomen : the abdomen is elongate, tapered and sub- 

 cylindrical, never as wide at its base as the thorax. The 

 surface is pollinose, the pile abundant, fine, subap- 

 pressed and setate. The lateral margins bear longer pile 

 on the first three segments and in the type of genus on 

 the first five segments. In the type of genus dense, 

 conspicuous, long, fine pile is on all the stemites, in 

 contrast to other members of the genus. Sides of the 

 first tergite with stout bristles. The subposterior mar- 

 gins laterally on the remaining tergites have at least 

 several, slender bristles. Males with eight tergites, the 

 eighth tergite generally quite short dorsally, or even 

 reduced to a membranous portion and little more con- 

 spicuous laterally ; in others the eighth tergite is mod- 

 erately long and from a third to half as long as the 

 seventh segment. Females with seven tergites ajDart 

 from ovipositor. Male terminalia large, with long, su- 

 perior forceps, sometimes notched distally. The gono- 

 pod is only half as long ; the hypandriiun is rather long 

 with transverse margin. The aedeagus forms a single 

 tube. The female terminalia are characteristic with a 

 broad, hoodlike structure about as long as wide, later- 

 ally lapping over the corresponding sternite. Ninth 

 segment quite short, the tenth a little longer. 



Distribution : Australian : Neoaratus hancrofti Hardy 

 (1935) ; A^rci^Zes Wiedemann (1828) [=giganteusM.2iC- 

 quart (1847), grandis Macquart (1848), plicatus 

 Wiedemann (1830)]; inglorius Macleay (1827) 

 [^Um.ycla Walker (1855), planus Walker (1855)]; 



