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UNITED STATES NATIONAL MUSEUM BULLETIN 224 



Head, anterior aspect : The head is wide, at least two 

 times the height and the face is also quite wide. The 

 face is a little more than a third the head width and 

 it is a little wider below. The front is slightly widened 

 and the vertex of nearly the same width. Surface of 

 face polished and bare except for a lateral triangle of 

 micropubescence. In the middle the subepistomal 

 margin may bear 2 or 3 minute hairs. The front is 

 strongly swollen over the medial half, divided from 

 the lateral part by a rather distinct, longitudinal crease. 

 This lateral portion bears a patch of long, coarse hairs, 

 and similar, stouter hairs occur submedially immedi- 

 ately behind and to one side of each antenna. Vertex 

 rather prominent but not high, with the ocelli large, 

 protuberant, crowded forward and pile restricted to 

 the postocellar area. Frontal creases continued behind 

 the vertex. Anterior eye facets a little enlarged. 



Thorax: The mesonotum is comparatively high an- 

 teriorly and slopes off posteriorly. The entire thorax 

 is exceptionally high. Mesonotum anteriorly abrupt 

 and a little concave medially. The surface bears mod- 

 erately abundant, undifferentiated, fine, bristly hairs or 

 setae which are nearly erect and which become a little 

 longer and more scanty laterally ; bristles are virtually 

 wanting. On the notopleuron are 2 quite slender 

 rather short elements and above the wing are even 

 shorter bristles; the postalar callosity has 1 similar, 

 weak bristle. The comparatively thin, basally flattened, 

 posteriorly convex scutellum has only a few scattered 

 hairs. Humerus anteriorly with a few fine, coarse 

 hairs ; it is situated well below the anterodorsal, swollen 

 part of the mesonotum. Metanotum peculiar and re- 

 markably large and swollen with a little pollen and a 

 few fine, scattered hairs in the middle and also ventro- 

 laterally. Much of the mesonotum has micropubes- 

 cence or pollen but the sides and almost the whole 

 pleuron polished and bare. The propleuron is reduced 

 in length and pile, the pronotum indented medially and 

 bearing a few coarse hairs. Mesopleuron, sternopleu- 

 ron, pteropleuron, and hypopleuron with sparse, fine 

 pile; similar but more copious and longer pile is sit- 

 uated on the metapleuron. Postmetacoxal area with a 

 narrow, complete band of chitin behind the coxa. 

 Presternum completely dissociated. 



Legs : All the femora are long and slender, especially 

 the hind femur, which is slightly dilated distally and 

 curved medially on the basal half. The legs are pol- 

 ished and bare, except for occasional, minute hairs and 

 comparatively short, almost stout, sharp, thornlike 

 bristles. The complement of bristles on the hind femur 

 consists of 4 short lateral, 4 dorsolateral confined to the 

 outer half, of which the last 3 bristles are conspicuous, 

 and 5 ventral bristles chiefly distal and stronger to- 

 ward the apex. This tibia bears 4 lateral and 6 dorsal 

 bristles with the basal element double and the last 2 

 bristles shifted to a slightly more lateral position. The 

 hind basitarsus has exceptionally stout, rather numer- 

 ous bristles. Middle femur rather similar to the hind 

 pair, with 4 anterior, 2 apical anterodorsal, 2 postero- 

 dorsal, and 4 to 6 ventral bristles. Its very long, 



slender tibia, which is slightly dilated distally, bears 

 8 lateral and 6 posterodorsal bristles, with the basal 

 element doubled, and 6 posteroventral, the basal ele- 

 ments weak. There are also 4 ventral bristles and 1 

 prominent ventrolateral bristle near the apex. An- 

 terior femur with weaker bristles. There are 4 or 5 

 distal, short, posterodorsal elements, 1 more conspicu- 

 ous anterodorsal bristle, at the apex and 3 ventral 

 bristles at the apex. This tibia is slightly narrowed 

 at the base and bears 8 short, anterodorsal bristles, 6 

 anterior bristles or stout setae, with the last near the 

 apex being quite stout and conspicuous. It also bears 

 7 posterior bristles and 2 or 3 prominent distal ventral 

 bristles, besides a considerable number of miscellaneous 

 setae; along the middle is only a ventral brush of dense, 

 ranked setae. Apex with a long protuberance and a 

 rather short, stout spine and the basitarsus with a 

 curved, distally directed flange and minute, short, con- 

 ical denticles. 



Anterior basitarsus quite long, slender, longer than 

 the remaining segments combined. Claws slender, 

 sharp; pulvilli well developed and broad, with only 1 

 rib; empodium short, bladelike. Ventroapical bristles 

 beside the empodium are flattened and swollen. 



Wings: The wings are hyaline and avillose, with 

 most veins pale. Marginal cell narrowly closed, wide 

 apically. Anterior branch of third vein long, sinuous, 

 ending well above the wing apex, the posterior branch 

 far behind. First posterior cell slightly narrowed, 

 fourth posterior cell closed with a short stalk, or closed 

 in the margin or narrowly open. Posterior crossvein 

 short, anal cell closed, the third vein branches op- 

 posite the end of the discal cell. The wing is long and 

 slender; the ambient vein complete; the alula well 

 developed. 



Abdomen: The abdomen is rather small and short, 

 considerably shorter than the wings and at the base no 

 wider than the mesonotum. It is largely bare, with 

 prominent, transverse striations and scanty, fine, erect 

 pile, a little more abundant posteriorly on each seg- 

 ment. Some setae or coarse pile occur on the last 2 

 segments, but no bristles are present. The middle of 

 the second segment and the subbasal part of the third 

 segment each have a transverse fossa. Fourth to sev- 

 enth segments with an odd, oval-shaped pitlike de- 

 pression sublaterally, perhaps the basis for muscle 

 attacliment. Males with seven segments, the seventh 

 rather short. Females likewise with seven segments, 

 the last two rather short and of equal length. Male 

 terminalia elongate, bulblike, somewhat swollen and 

 completely rotate. The long 1 epandrium is simple and 

 distally a little narrowed; the proctiger emerges from 

 below at the end. The gonopod represents the most 

 prominent part and is swollen and convex laterally, 

 though a little narrowed and compressed posteriorly 

 and with a lateral posterior notch; the halves almost 

 enclose the genital cavity, which faces upward because 

 of rotation. I have not dissected these terminalia but 

 I do not find any clear evidence of the hypandrium, 

 although what appears to be the eighth tergite is well 



