66 



Abdomen opaque black, the side margins and lateral spots on each segment 

 metallic greenish, the first segment wholly of this color. The shining side 

 margins are dilated on the basal two-thirds of the second segment to occupy 

 one-fifth the width of the segment on either side; sub-basally on the basal 

 third or less of the two following segments and over three-fourths of the fifth 

 segment, the shining margin is dilated to occupy more than one-third the width 

 on either side, its posterior margin oblique, the inner half of the fasciae thus 

 formed on the third and fourth segments covered with hoary bloom. Pile 

 rather sparse, yellowish on the metallic areas and base of the abdomen; else- 

 where shorter, sub-appressed, black. 



Holotype, cf , Fort Kent, Maine, August 17, collected by Charles 

 W. Johnson; in the Museum of the Boston Society of Natural 

 History. 



Stenosyrphus vittifacies, new species. 



Belongs to the sodalis group (for definition of this group and 

 key to species, see Canadian Entomol., vol. 55, p. 59, 1923). 

 The black facial stripe brings it close to S. nigrifacies Curran; 

 the abdominal spots, which do not reach the side margins, ally it 

 with S. contumax Osten Sacken. The spots are not or are scarcely 

 concave in front and the species does not, in this respect, agree 

 with the other members of the group. 



Male. — Length, between 9 and 10 mm. Face broadly yellow on the sides 

 and narrowly across immediately below the antennae; the cheeks, very broad 

 oral border and middle stripe, shining black, the median stripe elongate tri- 

 angular, reaching nearly to the base of the antennae as an acute point; the 

 yellow ground is covered by grayish pollen, which also encroaches on the black 

 ground. Jowls more brownish. Pile moderately long, fairly abundant, black. 

 Frontal triangle black, densely gray pollinose so that the ground color is mostly 

 obscured; narrowly bare immediately above the antennae where it forms a 

 broad, poorly formed W; pile black. Vertical triangle greenish black, thinly 

 grayish-yellow pollinose, its pile black. Occiput densely grayish polHnose, 

 clothed with pale-yellowish pile, the orbital ciliae black. Antennae black; 

 third joint obtusely oval, one and one-fourth times as long as broad, widest 

 sub-apically. Arista as long as the antenna, thickened on the basal third, 

 wholly black. Eyes touching for a distance equal to the length of the vertical 

 triangle, thinly short, yellow pilose. 



Thorax aeneous, the disk somewhat dull, with several obscure, narrow, more 

 shining vittae; pleura thinly whitish poUinose. Pile moderately long, chiefly 

 yellowish; on the sides of the mesonotum and on the mesopleura above, black, 

 or largely so, the pale pile also appearing tipped with black in some lights. 

 Scutellum reddish yellowish, the base narrowly black, the whole border metallic 

 blue; the pile long, black, pale and shorter basally. 



Legs black, the apices of the femora reddish, the hind ones less broadly so ; 

 the base of the posterior tibiae, and the front four tibiae, except obscure 

 brownish bands lying mostly beyond the middle, reddish yellow. 



Wings cinereous hyaline, the stigma luteous. Squamae whitish, with yellow- 

 ish border and fringe. Halteres yellow, the knobs somewhat ferruginous. 



Abdomen opaque or sub-opaque black, the first segment, sides of the whole 

 abdomen, apical third of the third segment, apical half of the fourth and the 

 whole of the fifth, shining; first segment brownish. Second segment with a 

 pair of rather small, sub-oval, yellow spots about the middle, well separated 



