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UNITED STATES NATIONAL MUSEUM BULLETIN 224 



third segment, a microsegment and shoi-t, fine pile. In 

 addition, in the male, the costa, subcosta, and the mar- 

 ginal and submarginal cells are strongly expanded and 

 rippled. Length 15 to 20 mm. 



Head, lateral aspect: The face is rather short and 

 gently convex, receding below. The eye is moderately 

 convex anteriorly but straight in profile posteriorly, al- 

 though at the immediate vertex it is a little convex, 

 and on the lower fourth it is strongly, obliquely reces- 

 sive anteroventrally. The occiput is short,_ equally de- 

 veloped above and below; its pile exceptionally fine, 

 moderately abmidant in the middle, very dense ven- 

 trally and likewise rather dense and longer dorsally 

 behind the vertex; bristles begin at the upper third 

 and are long, but exceptionally slender; there are 10 

 pairs, the upper elements strongly proclinate. The 

 proboscis is miusually slender and of moderate length 

 and subcylindrical, directed chiefly downward with a 

 few, fine "hairs at the apex and considerable long, fine, 

 ventral pile in the middle on the basal half as well as 

 a sublateral tuft which is subbasal in position. Palpus 

 slender, cylindrical, with fine apical and dorsal bristles. 

 The antenna is attached at the upper fourth of the head, 

 miusually slender, and moderately elongate. The first 

 segment is a little longer than the second, the second 

 rather attenuate basally. The third segment is as long 

 as the basal segments combined but not as wide at its 

 base as the second segment; it is rather strongly at- 

 tenuate, the apex quite narrow. A long microsegment 

 is present and a short, rather slender style with apical 

 bristle; microsegment and style together are a little 

 more than two-thirds as long as the third segment. 

 First segment ventrally with numerous, exceptionally 

 long, slender bristles or bristly hairs continued laterally 

 and dorsally. Second segment ventrally with 2 pairs of 

 equally long, more distinct bristles and some shorter, 

 bristly pile. 



Head, anterior aspect : The face below the antenna is 

 a fourth the head width, expanded below. Subepisto- 

 mal area moderately large, nearly plane, bare and ob- 

 lique. The face is densely pubescent and bears an ex- 

 ceedingly wide, dense, vertical band of pile begimiing 

 immediately beneath the antenna, the dorsal part con- 

 sists chiefly of long, curved, stiff, black hairs with some 

 shorter, white, lateral hairs and also some longer, white 

 lateral hairs. In the middle and ventrally and laterally 

 along the sides of the subepistoma the pile is equally 

 dense, chiefly whitish and longer than the dorsal, black 

 pile. The face is narrowly apilose laterally. Front ex- 

 ceptionally short, the ocellarium set forward and low ; 

 front pollinose, with a lateral tuft of 12 to 15 long, 

 slender, bristly hairs. Vertex deeply excavated, more 

 so posteriorly with vertical sides ; ocellarium large but 

 low, bearing across the middle 7 or 8 pairs of long, 

 quite slender hairs and behind the ocelli at least 3 pairs. 

 Anterior eye facets only moderately enlarged. 



Thorax: The thorax is minutely pubescent, ahnost 

 pollinose in character. Mesonotum strongly convex an- 

 teriorly and posteriorly, distinctly compressed ob- 



liquely and laterally on the anterior third. Pile of 

 mesonotum abundant but exceptionally fine, moder- 

 ately long and erect; there is in the acrostical area a 

 dense, medial mane of long, somewhat posteriorly 

 curved, slender black bristles and bristly hairs ; it be- 

 gins on the anterior margin, extends back within a short 

 distance of the scutellum and becomes still more dense; 

 there are fine, long, bristly hairs in the dorsocentral 

 line. Humerus with numerous, fine hairs. In the type 

 of genus the stout, long, lateral bristles consist of 3 

 notopleural in an oblique row, 1 postsupraalar, and 1 

 postalar, with other long, but quite fine hairs; the scu- 

 tellar margin has only the most slender bristles or 

 bristly hairs, of which there are 8 long pairs. The disc 

 is densely beset with long, bristly, pale pile, changing 

 in the middle basally to black, and becoming also more 

 bristly. Scutellum tliick, convex, pubescent, with dis- 

 tinctly impressed rim. Proplem'on densely long, fine 

 pilose, continued in a wide band on the pronotum; 

 bristles absent. Mesopleuron dorsally with long, fine 

 pile, stemopleuron with long pile anteriorly and in the 

 middle dorsallj'. Pteropleuron with a dense, dorsal 

 tuft of exceptionally long pile. Posthypopleuron with 

 numerous, bristly hairs that become crinkled distally. 

 Metapleuron with a wide band of long pile; metanotal 

 slopes micropubescent only; postlateral metasternum 

 with some long pile but the ventral metasternum 

 densely covered with exceedingly long, fine pile ; post- 

 metacoxal area membranous; tegula and basalare pu- 

 bescent only ; squama with multiple fringe. 



Legs : All the femora are a little swollen, especially 

 the first four; these strongly swollen towards base. 

 Tlie dorsal pile is quite fine, moderately long and sub- 

 appressed. In the type of genus the stout bristles 

 present on the hind femur consist of 7 ventrolateral 

 with 4 additional ventromedial on the basal fifth and 

 1 or 2 ventromedial subapically ; in addition there are 

 at least 5 strong, lateral bristles, and the apex has 2 

 dorsomedial, the subapex 1 dorsolateral bristle. Hind 

 tibia with 4 dorsomedial, 3 or 4 dorsolateral, 2 ventro- 

 lateral on the outer half, and 2 short, ventromedial 

 near the apex; apex with 1 minute dorsomedial, 1 

 dorsolateral, 1 ventrolateral, 3 ventral, and 1 medial 

 bristle. ISIiddle femur with 5 stout, anterior bristles, 

 3 of them on the basal third, with 5 stout anteroventral 

 on the basal third, and 2 additional bristles beyond the 

 middle. Middle tibia as well as the anterior and pos- 

 terior margins of the femur with numerous, long, fine 

 hairs; tibia with 2 strong anterodorsal on the distal 

 half, 3 or 4 quite weak posterodorsal, 3 or 4 postero- 

 ventral, and 3 strong anteroventral bristles. Anterior 

 femur with long, dense, fijie pile posteriorly and ven- 

 trally; its tibia has 5 or 6 weak, short bristles pos- 

 terodoi-sally and 5 or 6 long, attenuate posteroventral 

 bristles. Claws slender, sharp, strongly bent at the 

 apex ; pulvilli long and spatulate ; the empodium short, 

 alDout half as long as the claw, a little thickened at the \ 

 base. 



Wings : In the wings opposite the anterior crossvein I 

 the costa is thickened and together with the subcostal, 



