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UNITED STATES NATIONAL MUSEUM BULLETIN 22 4 



The bristles are unusually stout and begin at or just 

 below the middle of the head. There are about 12 on 

 each side. The face is moderately produced but never 

 extensive; it grows gradually more prominent below 

 and is slightly convex in profile. Proboscis short, 

 not extended beyond the face, cylindrical, with a blunt 

 apex which bears fine pile and the base is sometimes 

 a little swollen. Palpus small and cylindrical; the 

 first segment is minute, the second bears no apical 

 bristle but has a few, fine, short setae laterally and 

 below. The antenna is attached a little above the up- 

 per third of the head and is of only moderate length. 

 The first segment is long or barely longer than the sec- 

 ond but has 2 isolated, very stout, long bristles ven- 

 trally and sometimes ventrolaterally 2 other shorter 

 bristles as well as a few other minute setae. Second 

 segment with only a few setae near the apex above 

 and below. The third segment is a little longer than 

 the combined length of the first two and is either 

 gradually dilated until it is widest in the middle and 

 equally narrowed beyond, or is attenuate at the base 

 and more abruptly widened just before the middle. It 

 bears a distinct, short, cylindrical microsegment with 

 oblique, truncate apex and minute spines. 



Head, anterior aspect: The head is nearly twice as 

 wide as high ; the face below the antenna is more than 

 one-fourth the head width and with nearly parallel 

 sides. Surface of face pollinose, with numerous, stout, 

 but comparatively short bristles which may extend 

 from the base of the antenna or may be restricted to 

 the narrow band above the epistoma. Subepistoma 

 of moderate size and nearly horizontal; sometimes 

 there is short, bristly pile laterally or a few minute 

 hairs scattered about. Front short, pollinose, with 

 a row of 1 to 4 stout, submarginal bristles. The front 

 is wider than the face and the vertex may be equally 

 wide or slightly narrowed. Vertex but little excavated 

 and pollinose; the ocellarium is small with 1 pair of 

 stout, long bristles and generally 1 or 2 minute hairs 

 behind the ocelli. 



Thorax: The mesonotum is moderately high, gently 

 convex, thinly pollinose and densely beset with very 

 minute, flat appressed setae, which are undifferenti- 

 ated. Humerus with or without 1 or 2 short bristles. 

 The lateral complement of rather stout and moderately 

 long bristles consists of 1 or 2 notopleural, 1 or 2 

 supraalar, 1 or 2 postalar and no scutellar bristles. 

 Scutellum thick, convex, with appressed, minute pile. 

 Pronotum with or without fine, slender bristles but 

 always with coarse pile. Whole pleuron pollinose, 

 with almost no pile; there are a few minute hairs or 

 setae on the prothorax, 2 on the posthypopleuron. 

 Mesopleuron without bristles. Metapleuron with a 

 vertical band of 12 long, slender, distally curved bris- 

 tles. Metanotal callosity pollinose only. Metasternum 

 bristly pilose, postmetacoxal area membranous. Pre- 

 sternum fused laterally. 



Legs : All of the femora are a little swollen and in 

 some species the hind femur may be strongly swollen, 



chiefly above but slightly below. The pile is dense, 

 fine, short and setate. Bristles are numerous, stout, 

 but generally quite short; the hind femur bears 7 or 

 8 ventrolateral bristles, 4 or 5 smaller, ventral bristles, 

 4 middorsal bristles, 1 medial subapical, and 1 dorso- 

 medial bristle, besides 2 basal medial bristles. The 

 hind tibia bears 3 dorsolateral and 2 shorter dorsal 

 bristles and 2 anterior bristles ; most of these lie on the 

 basal half. On this tibia are 4 very fine, nearly erect, 

 ventral hairs and the apex carries 9 bristles but 2 of 

 them are quite small. Middle femur with a conspicu- 

 ous bristle dorsally, anteriorly, and posteriorly at the 

 subapex and likewise 6 shorter, posteroventral bristles 

 and 2 or 3 ventral bristles besides 4 or 5 small anterior 

 bristles. In some species only the 3 bristles at the sub- 

 apex are present. The middle tibia bears 3 stout an- 

 terodorsal, 4 shorter dorsal bristles, 1 or 2 posterodor- 

 sal, 4 posterior, 5 posteroventral, and 2 slender, short, 

 ventral bristles. In some species the ventral bristles 

 are quite long. Anterior femur with a prominent bris- 

 tle at the subapex anteriorly and dorsally and 2 or 3 

 short bristles near the base ventrally and posteriorly or 

 sometimes only with the 2 bristles at the subapex. 

 This tibia bears 3 fine, anterodorsal bristles and 2 to 

 4 stronger, posterodorsal bristles; it also has 2 to 4 

 posterior bristles and sometimes in addition 2 or 3 

 posteroventral bristles ; in some species there may be 3 

 long, ventral bristles. Apex of anterior tibia without 

 spine. Tarsal segments slender, rather short, with 

 subapical circlets of 6 rather short but quite stout bris- 

 tles. Claws long, slender, sharp, apposed, slightly 

 curved, the hind pair more strongly curved and the 

 pulvilli absent. The empodium is long. 



Wings : The wings are broad, tinged with pale brown 

 to a varying extent. The marginal cell is closed with 

 a long stalk; the anterior branch of the third vein is 

 a little sinuous and ends a little before the apex of the 

 wing and the posterior branch ends far behind the end 

 of the wing. The base of the submarginal cell rises 

 abruptly. The discal cell ends in one vein nearly or 

 quite aligned with the end vein of the fourth posterior 

 cell. Fourth posterior cell closed with a long stalk. 

 The anal cell is closed and stalked, the alula moder- 

 ately large, and the ambient vein complete; the first 

 vein sometimes bears coarse setae. 



Abdomen : The abdomen is broad, robust and rather 

 short, shorter than the wings, the segments of nearly 

 equal length. The pile is dense, fine, quite short and 

 flat appressed. The sides of the first tergite bear 3 

 to 4 stout, short bristles; middle of the lateral margins 

 of remaining tergites with 1 equally stout bristle. 

 Males with six tergites, females with the same number. 

 Male terminalia rather small and short, partly rotate 

 and much of it recessed beneath the sixth tergite. The 

 proctiger is long, flat, trapezoidal with a medial groove. 

 The epandrium is broad and convex merging laterally 

 with the gonopod. The gonopod has a comparatively 

 slender, sharp, curved apical process and below a ven- 



