8 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.78 



Male. — Front rather wide, velvet black above, changing to yellow 

 a little below middle; frontal triangle almost equilateral, rounded 

 anteriorly, reaching only to middle of front, its outer margins 

 somewhat yellowish. Face rather wide, silvery yellow; second 

 antennal joint a trifle longer than third, blackened on upper edge 

 beyond base; third joint brown, reddish below and on inner side; 

 back of head black in ground color with coarse whitish hair, be- 

 coming delicate and quite dense below near the edge of oral cavity. 

 Mesonotum black on disk ; humeri whitish, the color extending back 

 to suture and down to front coxae as well as nearly halfway to the 

 middle line of mesonotum. Behind the suture the dark color ex- 

 tends broadly down the mesopleura. Above the wings the color is 

 yellow and there is a median divided yellow area beginning a little 

 back of the suture. Margin of scutellum yellow, metanotum black 

 in middle. Humeral bristle absent; notopleural only one; supra- 

 alar one. 



Abdomen mostly yellow; first segment broadly black above, the 

 sides whitish and bearing only delicate white bristles; second seg- 

 ment black, the sides yellow, broadly expanded toward the middle 

 above so that the black color is correspondingly narrowed, a stout 

 row of black bristles laterally at the base; third, fourth, and fifth 

 segments yellow with broad black hind margins extending forward 

 in the middle to form a median stripe ; the pale portion of the fourth 

 segment is distinctly white pruinose; sixth segment very narrow, 

 yellow; seventh (genital segment) largely yellow with black basal 

 spot on each side of middle; forceps yellow, inclosing between them 

 an oval area mostly filled with delicate pale hairs arising from the 

 inner sides of the forceps. Front legs yellow, last tarsal joint black- 

 ened ; tip of coxa with conspicuous long delicate pale hairs in front 

 and behind. Middle legs yellow; coxae with mixed smallish pale 

 and dark hairs. Tibia with an erect, short, black spine at tip on 

 flexor side ; tarsi black at tip and the apices of the first four segments 

 slightly infuscated. Hind femora yellow with two brown annuli, 

 the erect pile on the inner side extending only a little beyond middle. 

 Hind tibia yellow, apical third except extreme tip black, inner 

 surface with dense erect pile from above the middle. Hind tarsi 

 black, first segment more brownish in middle. 



Wing light brown, first posterior cell much widened beyond mid- 

 dle, last section of the fourth vein broadly curved, joining third a 

 little before tip, the united veins joining costa rather far before 

 apex; hind crossvein almost parallel with wing margin, longer than 

 last section of fifth vein and almost as long as penultimate section 

 of fourth. First posterior cell much wider than submarginal. Tip 

 of second vein slightly farther from base of wing than anterior end 

 of hind crossvein. 



