SYNOPSIS OF NORTH AMERICAN SYRPHID^. 191 



S ,9 . Length, 9.5 to 11""". Front of male not broad, the sides par- 

 allel on upper half; on the lower half, like the face, of a fine light 

 golden -yellow, with yellow dust and pile, not at all shining; on the 

 upper half, in front of the ocelli, thickly covered with a brownish-yellow 

 dust, the ocelli and vertex black, shining, and narrowly black pilose. 

 In the female the front is broader, and wholly clothed with black pile, 

 more abundant across the middle ; the ground color is shining black, 

 obscured by the pollen, which is less abundant and less yellow than 

 in the male. Antennae yellowish red; arista red at base. Face gently 

 concave below the antennae, then gently convex to the tip, the lower 

 part considerably produced downwards and forwards ; below shin- 

 ing black on the sides, back below the eyes on the cheeks obscured by 

 pollen. In the female the yellow color of the face is concealed be- 

 neath more whitish pile, so that it does not have the bright color of 

 the male. Dorsum of thorax light yellowish-olivaceous, with three 

 broad, black, opaque, velvety stripes, rather narrowly separated, but 

 more broadly so in the male than in the female; the outer stripes do 

 not reach quite to the front and back margins ; pleural pollinose. Scu- 

 tellum shining black, the border red, pile yellowish. Abdomen in the 

 male slender, narrowed at hind part of the second segment, yellowish 

 and ferruginous-red ; first segment grayish pollinose, except a small 

 spot near the outer sides behind, continuous with the anterior angles of 

 the black on the next segment; second segment broadly velvety black, 

 extending nearly the whole width of the segment in front, thence nar- 

 rowed so that at the middle of the segment it does not occupy more 

 than one-third the width ; then again expanding, usually of a less deep 

 color (sometimes only brown or ferruginous); the broad hind margin of 

 the segment shining red, the long lateral triangles are yellowish, along 

 the black in front often white pollinose; third segment sometimes 

 wholly and uniformly red, but more usually with a brownish or blackish 

 spot in front in the middle, and a diffuse, indistinct, brownish cross- 

 band before the broad shining hind margin, the sides in front, and two 

 spots near the middle, of white pollen, are often present; fourth segment 

 with a pair of small slender spots in the middle in front, and the an- 

 terior angles wliitish pollinose, the extreme hind border of the fourth 

 and fifth segments yellow. In the female the abdomen is broader, wholly 

 black, with grayish-white cross-bands ; first segment wholly dusted ; 

 second segment with a broad shining cross-band behind, elsewhere 

 velvety black, except the oblique, pollinose, yellow side-spots ; these 

 spots reach along the sides to the front angle of the segment, obliquely 

 concave in front ; third and fourth segments similar, but the spots are 

 very narrowly separated, beginning at the anterior angles, concave in 

 front, convex behind, the shining part of the fourth segment is some- 

 what dusted ; fifth segment wholly pollinose, except a narrow black 

 cross-band in front. Basal half of the front and middle femora, hind 

 femora, except the base and a preapical ring, the distal part of hind 



