390 Annals of the Carnegie Museum. 



second segments of abdomen yellow, third, fourth, and fifth segments 

 black, with narrow yellow basal bands interrupted in the middle with 

 black. Wings fuscous hyaline, the fuscous more pronounced in the 

 anterior half; second vein perfectly straight. Postvertical bristles very 

 strong. Length 4.5 mm. 



Description: Front broad, about one-third the width of liead, and its sides sHghtly 

 diverging upwards. Fronto-orbital region gray, wide at vertex, gradually narrowed 

 below and reaching only to immediately below the lowermost fronto-orbital bristle. 

 Ocellar triangle gray, rest of front brownish yellow, but in certain lights the whole 

 front appears gray. Front provided with minute black hairs, apparently placed in 

 transverse rows, and with minute, black, orbital setulae close to the eye from the 

 lower reclinate fronto-orbital bristle to the lower edge of front. Face yellow, gray- 

 ish pollinose, with a very slight, transversely convex carina. Antennae yellow with 

 third joint, except its base, grayish pollinose and about one and a half as long as 

 wide; arista black, yellow at base, with seven rays above and four below (alike in 

 both antennae). Palpi yellow, not at all prominent. Upper occiput black with the 

 vertical border and a spot in the middle yellow. Cheeks narrow. Mesonotum and 

 scutellum a little shining, dark brown-red, in certain lights with a light yellowish, 

 silky bloom. Mesonotum with the minute setulae black. The scutellum with the 

 extreme apex and underside pale yellowish. Metathorax and pleura lighter brown- 

 red, in certain lights with a thin, grayish lustre. Sternopleura with some scattered 

 minute hairs besides the row of minute hair-like setulce, which runs from the an- 

 terior sternopleural bristle downwards. Legs yellow; middle and posterior tibiae 

 with a small, but distinct, preapical bristle. Halteres yellow. 



Abdomen blackish, slightly shining on the basal, but more so on the apical seg- 

 ments. The small first segment entirely, and the second segment, except a black 

 dot on each anterior corner and its extremely narrow black apical border, yellow; 

 on each of the third, fourth and fifth segments a narrow, basal yellow band, inter- 

 rupted with black in the middle (most widely on fifth segment) the bands not reach- 

 ing the lateral margin. Venter yellow. 



Wings fuscous hyaline, the fuscous more intense anteriorly, especially in costal 

 and marginal cells. 



The third vein ends at the very apex of the almost imperceptibly pointed wing; 

 the second vein runs perfectly straight to the costa; the distance between the tips 

 of second and third veins about two and a half times the distance between the tips 

 of third and fourth veins, which are parallel in their apical course, and, as the third 

 vein is only gently curved forwards, the first posterior cell is only a little narrower 

 at apex than at middle; the distance between anterior and posterior cross-veins is 

 one-third longer than the first section of third vein, and less than one-half of the 

 length of the ultimate section of fourth vein; posterior cross-vein a little shorter 

 than the ultimate section of fifth vein; anal vein long, reaching fully two-thirds of 

 the distance to the hind margin of the wing; fourth vein not so unusually thin in its 

 apical course as in the other species before me; all veins brown, none conspicuously 

 lighter. 



Oral vibrissse strong; the fronto-orbital, ocellar, vertical and postvertical bristles 



