]: 



590 



UNITED STATES NATIONAL MUSEUM BULLETIN 22 4 



pile is fine, curled, tufted, dense and moderately long. 

 Bristles begin below the middle of the head and consist 

 of 12 to 14 pairs; they are pale and moderately stout; 

 the bristles at or just above the middle are turned down- 

 ward, the upper and stiffer bristles are slightly curved 

 and directed upward ; lower corner of the occiput ad- 

 jacent to the eye with 3 long, weak bristles. Proboscis 

 of moderate size, but the apex blunt and slightly tap- 

 ered above; the dorsal ridge is high, the whole struc- 

 ture subcylindrical with the base a little swollen and 

 with fine, scattered, long pile below. Palpus of one 

 segment, with stiff, long hairs apically and ventrally, 

 shorter pile laterally and dorsally. The antenna is at- 

 tached shortly below the upper third of the head, slen- 

 der but of oniy moderate length. The first segment is 

 a little longer than the second. The third is as long as 

 the first two segments combined ; this segment is slen- 

 der and tapers from near the base to the apex ; it bears 

 a short raicrosegment and a short style approximately 

 three-fourths as long as the third segment ; style with a 

 minute apical spine. 



Head, anterior aspect : The face below is a fifth the 

 head width and divergent below to a third the head 

 width. Subepistomal area long, concave and pubes- 

 cent. The face is pubescent; pile and bristles are re- 

 stricted to the lower third; in the center below, is a 

 small patch of weak bristles and stiff, long hairs di- 

 rected forward; above are 2 moderately stout bristles 

 and 2 weak bristles and 4 or 5 hairs. Lower anterior 

 margin of the epistoma and the lateral margins with a 

 double row of bristles ; the lowermost elements consist 

 of 12 pairs of slender bristles or stiff hairs: above them 

 lie stiff, long bristles, 3 laterally and 4 pairs in the 

 middle. Still higher in the middle of the face is an 

 additional row of 3 pairs, and above these a single 

 pair; in the midline of the face there may be a single, 

 long bristle. The front is slightly divergent, the ver- 

 tex distinctly more convergent, both pollinose. Sides 

 of front with a row of short, appressed bristles and a 

 patch above the antenna containing 2 stouter bristles 

 and some fine hairs. Vertex only moderately exca- 

 vated but with steep sides. Ocellarium small, contain- 

 ing 2 or 3 pairs of fine, short setae. Eyes centrally 

 enlarged. 



Thorax ; The mesonotiim and pleuron pollinose. The 

 pile of mesonotum is quite scanty but more or less uni- 

 formly distributed and composed of short, basally 

 stout, fine, suberect setae. Acrostical elements are mi- 

 differentiated ; dorsocentral elements imdifferentiated 

 anteriorly but at the anterior postalar level they are 

 developed into moderately long, stout bristles, 4 on 

 each side. Humerus pilose. Lateral bristles of the 

 mesonotum are stout, long and consist of: 2 noto- 

 pleural, 1 postsupraalar, 1 suprapostalar, 2 postalar, 

 and 1 pair of scutellar bristles widely spaced. Sciitel- 

 lum convex, thick, pollinose, with impressed rim; the 

 disc bears a number of fine, erect, scattered hairs. Pro- 

 pleuron with abundant, long, fine pile. Pronotum with 

 5 pairs of widely sjiaced, slender bristles ; ventral pos- 

 terior propleuron with 3 short, distinct bristles. Upper 



margin of the mesopleuron and the anterior prolonga- 

 tion with numerous, fine, erect hairs ; posterior margin 

 with only 1 or 2 hairs. Upper stemopleuron with 10 

 or 12 long, fine hairs; lower posterior stemopleuron 

 with several long, fine hairs; upper pteropleuron with 

 a few, fine hairs, posthypopleuron with 5 long, weak 

 bristles; the metapleuron has a vertical row of 6 

 equally weak, long bristles. Metanotal slopes pubes- 

 cent with a patch of 12 or more fine, stiff hairs. Lat- 

 eral and ventral metasternum with numerous, scat- 

 tered, long hairs; i)ostmetacoxal area membranous; 

 tegula pubescent only ; squama with a multiple fringe. 

 Prostermun fused. 



Legs: The legs are stout, the anterior and middle 

 paii-s slightly thickened; the ventral aspect of the 

 middle femur is plane, the dorsal margin convex ; ven- 

 tral margin of the posterior femur not plane; these 

 femora are slightly narrowed towards the base and 

 again close to the apex. Pile of femora and tibiae 

 abundant, flat appressed and setate, with scanty 

 amounts of fine, erect, ventral pile which on the hind 

 femur is absent, except medially. The hind femur 

 bears stout bristles as follows: 1 at the dorsomedial 

 apex, a pair subapically and dorsally, the outer mem- 

 ber of which forms one of a lateral row of 4 ; there are 

 5 ventrolateral and 4 longer ventral bristles, 2 of them 

 situated at the base. The hind tibia has 1 strong, long, 

 dorsomedial in the middle, 3 dorsolateral, and 3 ven- 

 trolateral bristles. A brush of setae takes origin from 

 the middle and extends on to the first two tarsal seg- 

 ments. Basitarsus as long as the next three segments. 

 Middle femur with a stout bristle posteroapically, 2 

 anterior, 3 anteroventral and 4 ventral bristles on the 

 basal half. This tibia has 2 dorsal and 2 anterodorsal 

 restricted to the outer half, 3 posterior, 2 long, postero- 

 ventral and 2 long ventral bristles; both sets are re- 

 stricted to the outer half. Anterior femur with 4 or 5 

 long, slender bristles ventrally on the basal half. 

 Anterior tibia with 3 or 4 short dorsal and with 3 ex- 

 ceptionally long, stout posteroventral, together with a 

 ventral fringe of 4 or 5 quite long, slender, bristly hairs 

 increasing in length distally ; apical circlet with 2 dor- 

 sal, 2 medial, 2 anterior and 6 or 6 ventral elements. 

 Apical bristles of anterior and middle tarsi exception- 

 ally long. Tarsi end in long pulvilli ; slender, long em- 

 podium ; sharp, apically curved claws. 



Wings: The wings are hyaline, the marginal cell is 

 closed with a short stalk; the anterior branch of the 

 third vein ends above wing apex, the posterior branch 

 well behind the wing apex. First posterior cell nar- 

 rowed by the basally swollen second posterior cell; 

 fourth posterior cell closed and stalked but only 

 slightly convex anteriorly. Lower end vein of discal 

 cell pulled back toward the base; second basal cell ends 

 in 2 veins or a very short middle vein ; anal cell closed ; 

 alula large; ambient vein complete. 



Abdomen: The abdomen is slender, subcylindrical 

 and tapered, longer than the wings. The first tergite 

 is laterally swollen and convex. Pile of abdomen abun- 

 dant but quite appressed and setate. There are a few 



