50 



ITNITED STATES NATIONAL MUSEUM BULLETIN 263 



Tluii'ax l.o times as long as wide, iil)ioiig. Mesdiniliiiii 

 (pi. 19, fig. 7) as long as wide, blackish brown, wiih 

 lateral borders soinewliat yellowish, more or less ob- 

 scvired by whitish toineiitum, witli light yellow short 

 pubescence; humeral calh liglit yellow, more or less 

 shining, with a few yellowish long erect pubescence on 

 externo-anterior border': notoplcural calli compaia- 

 tively large, yellowish lnuwii, sdniclinH'^ diukened, 

 sliglitly obscured by wliitisli lonienluni; sculc^liiini 

 nearly three limes as wide as long, light i\(iiv yellowish 

 with basal margin more or less l)i(i\\n, posl(>rior margin 

 rounded; mesophragnia luid poslnotum concolorous 

 witii mesonoluni. Pleura (pi. 19, fig. 8) conspicuously 

 paler llian notuni, antero-inl'erior border yellowish, 

 posterior l)order of mesopleiu'on sometimes whitish, 

 with light colored, very s])arse, erect fine hairs, ventral 

 border of sternopleuron with black bristly hairs. All 

 bristles black: scapulars fine, comparatively long, 

 inner pair as long as outer and situated closely to each 

 other; humerals as long as ])resuturals, situated at 

 midille of callus; notopleurals a little shorter than 

 humerals, the anterior slightly longer and finer than 

 posterior; dorsocentrals on a line connecting anterior 

 su])ra-alars; pi-escutellars at the le\el of inner posterior 

 supra-alars, distinctly shorter than hitter; outer 

 posterior supra-alars conspicuously curved, shorter 

 than inner; scutellars two pairs, the apical i)arallel 

 but slightly curved inward: meso|)leurals two, between 

 them sometimes one short, fine l)ristle; pteropleural 

 directed posteriorl\-; sternopleural directed dorsally. 



Abdomen (pi. 19, fig. 9) nearh' as long and as wide 

 as thorax, black, more or less obscured bj^ greyish-w hite 

 tomentum except fifth tergum, which is blackish pubes- 

 cent; second tergum with long erect hairs on lateral 

 borders, third to fourth terga with very sparse bristly 

 hairs along [josterior margins; genitalia yellow; sterna 

 yellowish brown to reddish brown, often with a narnnv 

 paler posterior marginal band. 



Wing (pi. 19, fig. 1) comparatively large, distinctly 

 longer than body; costal vein almost attaining middle 

 of a])ex of R5, with comparatively short costal spine 

 which is not distinctly longer than costal bristles; 

 R2+3 nearly straight, a veinlet, which is often obsolete, 

 beyond its middle in Rj; R^+j sparsely bristled from 

 base to before tij), a very short veinlet i)roxunal to 

 middle of R5; m slightly divergent from R4+5; r-m not 

 oblique, situated at middle of IM2; m-cu straight, 

 nearly ])erpciulicidar, IM2 Math moderately sharp 

 posterior angle; pterostigma slightly shorter than second 

 costal cell; the apex sharp, light yellowish; anal cell 

 shorter than basal cell, but with a very long inferior 

 prolongation nearly as long as cell proper. Wing-pattern 

 brown, as follows: costal band narrow from base of 



pterostignui to middle of apex of R5 along costa, its 

 posterior margin more or less notched at R2+3 and R4+6; 

 fi\e distinct transverse bands, the basal straight from 

 basal third of second costal cell to base of anal cell, 

 subbasal from base of pterostigma to end of anal vein 

 idong apical portion of M and anterior border of apical 

 margin of aruvl cell, median from Ro_,.3 to behnv cu along 

 r-m, subapical from middle of apex of Rj to end of cu 

 on m-cu, then bent to middle of apex of Cu along 

 wing-margin, apical usually faint, from R4+5 to near 

 apex of 2M2. Hal teres light yellowish. 



Legs light yellow with paler tarsi and front tibiae, 

 brown pubescent. Foreleg (pi. 19, fig. 11) consjiicuously 

 shorter than others; femur slightly longer than tibia, 

 externodorsal margin with one row of four or five black 

 bristly hairs on apical half, external surface with one 

 row of six or seven black bristly hairs near middle, 

 externoventral nuirgin with one row of seven black 

 long bristly hairs, of which the two basal are slender 

 and two apical are short; tibia as long as tarsus, pubes- 

 cence on dorsal margin somewhat longer; first tarsal 

 segment as long as four following segments together, 

 half as long as tibia, brushlike bristles on internoventral 

 surface brown and moderately dense, black bristles 

 on ventral surface of four apical segments rather sjjarse. 

 Midleg (pi. 19, fig. 12) somewhat longer than hindleg; 

 femur as long as tibia, externoventral surface more or 

 less brownish on apical two-thirds, externoventral 

 margin with a conspicuously long hair near base and 

 bristly hairs near apex; tibiae with a strong and long 

 apical spur, m addition very short bristles along apical 

 margin; tarsi a little shorter than tibia, first segment 

 longer than the ionr following segments together, 

 brushlike bristles on internoventral surface rather 

 s])arse, black short bristles on ventral surface of four 

 apical segments very small and numerous. Hindleg 

 (pi. 19, fig. 13) with apical half of femur and sometunes 

 a spot just before middle of tibia brownish; femur 

 distinctly longer than tibia, bristly hairs, of which 

 two are conspicuously long, well ])roximad of apex of 

 dorsal surface, externoventral margin with three long 

 hairs near base and bristly hairs near apex; tibia with 

 one row of bristles, on external surface, these becoming 

 short and faint toward both ends; first tarsal segment a 

 little longer than half tibia, longer than the four 

 following segments together, bristles as in midtarsus. 



Length: Body 4-5 mm, wing 4.2-5.3 mm. 



Female. — Quite similar to male. Third antennal 

 segment somewhat broader, the dorsal margin less 

 undulate and ventral margin strongly curved at apical 

 ])ortion; arista rather irregularly plumose. Palpi 

 comparatively broad, with truncate apex. Sixth 

 abdominal tergum (])1. 19, fig. 10) less than half as 



