l60 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I25 



Thorax : Mesonotum black ; two very large triangles of white 

 pruinosity, their bases 011 the anterior margin of mesonotum, extend- 

 ing posteriorly so that their apices join with the white pruinosity of 

 the prescutellar region ; distance between the two triangles equal to 

 at least width of one of the triangles ; lateral margins of mesonotum 

 also white-pruinose ; long, narrow, yellow, scalelike hairs around 

 periphery, dull brown in midregion ; few tan hairs on anterior margin 

 and in prescutellar region. Humeral angles brown, white-pruinose, 

 with yellow scalelike hairs. Scutellum brown to black, shiny, with a 

 few long black hairs and several yellow scalelike hairs. Postnotum 

 velvety black, white-pruinose. Pleura dark brown, evenly white- 

 pruinose. Stem of halter dark brown to black, the knob yellow. 

 Wings, 2.6 mm. long and i.o mm. wide; relation of length of body 

 to wing, 1.2 : I ; Sc pilose along basal third ; Ri spiny and pilose along 

 distal half ; R2+3 pilose along distal five-sixths ; Cus arcuate ; discal 

 cell absent. 



Legs : Leg i, length, 2.7 mm. ; coxa, trochanter, and femur brown ; 

 tibia with basal three-fourths tan, the apical fourth black ; tarsus black. 

 Leg 2, length, 2.4 mm. ; coxa black ; trochanter and femur dark brown ; 

 tibia tan on its basal three-fourths, black on apical fourth ; basitarsus 

 tan on basal two-thirds, black on apical third; tarsal segments 2-5 

 black. Leg 3, length, 2.9 mm. ; coxa, trochanter, and femur black ; 

 basal half of tibia tan, apical half black ; basal half of basitarsus and 

 of second tarsal segment tan, the remainder of these segments, as well 

 as all of segments 3-5, black ; relation of basitarsus to second segment, 

 4.8 : I ; calcipala well developed, almost reaching the pedisulcus ; pedi- 

 sulcus well developed on basal third of second segment. 



Abdomen: Tergite of segment i black, with short black hairs; 

 pleurites black, with long black hairs reaching segment 4. Segment 2 

 black, anterior half of tergite white-pruinose, with short, black hairs. 

 Other segments black, clothed with short black hairs ; pleura of seg- 

 ment 6 white-pruinose. Sternites tan. 



Genitalia: Sidepiece (pi. 24, fig. 46) somewhat cylindrical in 

 shape, longer than wide ; dorsal opening occupying approximately half 

 of dorsal surface of sidepiece. Gasper (pi. 24, fig. 46) somewhat 

 flattened, its length equal to about twice its width ; outer distal angle 

 rounded, the inner distal angle somewhat prolonged, with a single stout 

 terminal spine. Body of adminiculum (pi. 24, fig. 47) wider than long, 

 the apex prolonged, dome-shaped ; narrow, winglike expansions along 

 lateral margins ; entire ventral surface covered with both short and 

 long hairs, the longer ones more prevalent at the apex; basal proc- 

 esses rather short, well sclerotized, pointed. Arms of adminiculum 



