1915.] NATURAL SCIENCES OF PHILADELPHIA. 477 



Female. — Length, 15 mm.; wing, 10.5-11.8 mm. Middle leg, 

 femora, 4.9 mm.; tibiae, 4.5 mm.; hind leg, femora, 6.3 mm.; tibiae, 

 6.6 mm. 



Frontal prolongation of the head rather short, brownish yellow 

 with sparse black hairs above; nasus distinct; palpi with the first 

 two segments dull yellow, the apical segments darker. Antennae 

 long, graceful, if bent backward extending about to the base of the 

 fifth abdominal segment; the three basal segments dull j^ellow, the 

 remaining segments dark brown, uniform or nearly so. Front with 

 a tubercle, grayish passing into browTi on the vertex and thence 

 into buff on the occiput; frontal tubercle buff; a narrow black 

 median vitta from this latter becoming indistinct about the middle 

 of the vertex. 



Pronotum dull yellow to brown. IVIesonotal praescutum dull 

 grayish yellow with three distinct dark brown stripes, the median 

 one broadest, the lateral stripes small and less distinct; scutum 

 pale yellow laterally, duller yellow medially, the centre of the lobes 

 mostly dark brown; scutellum and postnotum dull yellow, whitish 

 pollinose. Pleura pale yellow, whitish pollinose, with brown mark- 

 ings before the base of the halteres, on the mesepisternum and 

 mesosternum; metanotum brownish. Halteres light yellow, the 

 knob dark brown. Legs with the coxae pale whitish pollinose, the 

 cephalic faces more or less suffused wdth brown, especially on the 

 hind legs; trochanters and femora yellow, the latter narrowly dark 

 brown at the tip; tibiae brownish yellow passing into dark brown 

 at the tip; tarsi dark brown. Wings pale yellowish brown, sub- 

 hyahne, the costal region more yellowish, the stigma more broA\Tiish 

 but indistinct; an interrupted vitreous band from before the stigma 

 into cell 1st M^; a vitreous spot beyond stigma in the base of cell Ri 

 (see Plate XVI, fig. 8). 



Abdomen with the first tergite silvery pollinose basally, bright 

 yellow on the terminal two-thirds; tergites two to four dull yellow, 

 each segment with a black median triangle, the point of which is 

 behind ; segment two Avith a dark brown ring about midlengt h of the 

 sclerite; segments three and four with this transverse ring subbasal; 

 lateral margins of these segments broadly pale yellow, inside which 

 is a broad dark brown band running the length of the abdomen; 

 segments five to seven dull yellow with the dorsal triangles and the 

 lateral pattern extensive, largely covering the segments; the black 

 lateral stripes end at the base of segment seven, so this segment is 

 largely yellomsh on the sides; segment eight dark brown except 



