86 



jointed, not shining, the third joint of male nearly three times as long as wide, 

 pubescent, two-thirds as long as the arista; of the female short ovate and one- 

 fourth or one-third as long as the arista; cephalic bristles small, blackish, two 

 pairs of verticals. Pubescence of the mesonotum fine but relatively dense, 

 humeri, notopleural suture, scutellum and pleurae densely whitish-gray prui- 

 nose, sternopleurae glabrous in front and in the middle behind; abdomen 

 brownish black, shining; pygidium large, spherical, minutely but densely 

 pubescent so as to appear pollinose under low magnification. Front legs not 

 thickened, front femora with fourteen fine short cilia below in the anterior row, 

 under side of the middle femora with about twenty-six black setulae in the 

 anterior row and about sixteen black setae in the posterior row, in back of which 

 are eight long stiff yellow setae; middle tibiae three-fourths as long as their 

 femora. Veins thin but firm and blackish; costa not thickened, its second, 

 third and fourth sections proportioned 4.4: 3:1; third vein recurved, ending 

 beyond the tip of the wing; cross- veins nearly transverse, located at three- 

 sevenths the length of the wing, meeting, the posterior nearly three times as 

 long as the anterior; sections of the fifth vein proportioned 0.5: 1 :1; anal cross- 

 vein at an angle of forty degrees, anal vein fine but distinct, marginal cilia 

 short. 



Thirty specimens; type from Moscow Mountain, Idaho, 

 August 23; paratypes from Pullman, Palouse, Mica, Washougal, 

 Everett, Tulalip, Lake Cushman, Lake Crescent and Vashon, 

 Washington; Moscow and Lake Waha, Idaho; Perma, Thompson 

 and Gardiner, Montana (Melander); Banff, Alberta (Garrett); 

 Price County, Wisconsin (W. M. Wheeler); Niagara Falls, New 

 York (M. C. VanDuzee); and Chester, Massachusetts (C. W. 

 Johnson). One specimen from Alaska differs in having the 

 posterior cross-vein located a little beyond the anterior. The 

 Atlantic Coast specimens have the notal pubescence very slightly 

 longer than the others, thus approaching P. pubescens. 



Platypalpus porrectus, sp. nov. 



9 . — Length 2.5 mm. Head globose, front and face short and relatively 

 broad, cinereous, the sides of the front diverging above, epistome black, mouth- 

 opening rather large; proboscis black, inner side of the oval palpi blackish, the 

 outer side white-pollinose ; one apical seta, antennae black, two-jointed, the 

 outer joint elongate, nearly four times as long as wide, rather shining and 

 pubescent, the slender arista about two- thirds as long as this joint; occiput 

 olivaceous cinereous, two pairs of vertical and one of ocellar bristles black. 

 Mesonotum moderately coated with olive-gray pollen, the bristles black, one 

 small humeral and one pair each of notopleural, supra-alar, postalar, dorso-cen- 

 tral and scutellar bristles; pollen of the pleurae whitish, sternopleural spot large; 

 abdomen shining black, the pits hardly noticeable. Legs testaceous, coxae black- 

 ish at the base, tarsi progressively dusky; front femora not ciliate but puberulent 

 beneath, middle femora with a few irregular blackish setulae on the anterior 

 face, not yellow-setose, but the black setulae of the posterior flexor row longer 

 than usual; spur of the middle tibiae minute. Veins blackish, costa swollen 

 at the insertion of the first vein, its second to fourth sections proportioned 

 2: 2.2:1; third vein straight, fourth vein slightly diverging, the first posterior 

 cell widest at the end, cross-veins meeting, the anterior two-thirds as long as 

 the transverse posterior, sections of the fifth vein proportioned 0.5: 0.6:1; anal 

 cross-vein at an angle of sixty degrees, anal vein weak over all; marginal 

 cilia short. 



