270 THE CANADIAN ENTOMOLOGIST. 



vitta brownish, dusted with grayish pollen ; two strong proclinate ocellar 

 bristles ; frontal bristles descending to insertion of arista ; outside the 

 frontal row two proclinate orbital bristles and a number of short black 

 bristly hairs in both sexes ; facial plate widening very strongly below, the 

 parafacials at lower corner of eye almost linear ; facial ridges ciliate on the 

 lowest fourth ; oral margin, cheeks and the occiput on and near the 

 margin with black bristles; width of the cheeks less than one-half the height 

 of the eye; head at vibrissal angles shorter than at base ot antennae; front, 

 face, cheeks and occiput covered with bluish-gray or lead-coloured pollen ; 

 antennae reaching to oral margin, which is not produced, second segment 

 short, third about five or six times the length of the second segment, in 

 the male cleft almost to the base as in S. conveda Walk.; the outer ramus, 

 which bears the arista at its base, is laterally compressed and at a point 

 about one-third of its length from the base, convex on the outer and con- 

 cave on the inner edge, the lower two-thirds of the outer ramus perceptibly 

 directed downward and inward toward the tip of the inner ramus ; 

 inner ramus rather broad, and antero-posterioraliy compressed ; when the 

 antenna is retracted, the inner side of the inner ramus is closely 

 appressed to the facial plate, and only its tip is visible from the side ; 

 inner ramus gently arcuate on its proximal three-fourths, the distal fourth 

 bending forward, its tip reaching a little below the tip of the outer ramus, 

 the two sometimes touching ; antennae dark brown, in some lights grayish 

 silvery ; female with the third antennal segment entire, not cleft, from 

 one-third to about half as wide as long, more or less broadened and 

 flattened, the lower hind corner rounded, the front corner angular, some- 

 times more or less projecting, the segment in some specimens more or less 

 reddish tinged, especially along the inner border; arista basal, dark brown, 

 with very short whitish pubescence, thickened almost to the tip, its first 

 segment short, second segment subequal or two-thirds the length of the 

 third ; palpi varying from yellow to brownish, more or less flattened, in 

 some specimens about half as wide as the proboscis. 



Thorax in ground colour black, rarely reddish tinged, covered with 

 bluish-gray, lead-coloured pollen, including the pleura ; with two strong 

 and two weak sternopleural bristles ; with three postsuturals and one 

 postacrostichal ; the mesonotum also with numerous short suberect bristly 

 hairs ; scutellum concolorous with mesonotum ; with two pairs of strong 

 lateral and a pair of weak apical macrocha^tae, and numerous strong, 

 bristly hairs. 



