FAM. EMPIDID/E 33t 
- 
oval; third vein ending beyond wing-tip; hypopleure 
Iueely polished w Ne re SEC E io r4 PC GLACIALIS, nov« ep-t(1). 
58. Front pollinose; mesonotal pubescence conspicuous; palpi 
Brownish velo GU o oSv you vx De v xs E PUEBESCENS, nOV. SD. (2). 
Front shining; mesonotal pubescence usually short; palpi 
pRIS BOW Tu des opel e SM LN. CS BINE : 59. 
59. Middle femora with 8 yellow flexor bristles, front femora 
with 17 short pale flexor cilia; palpi very large, nearly as 
long as the proboscis; halteres yellow . . . . . . . P.PrcriNATOR, Melander. 
Middle femora without conspicuous bristles; front femora not 
ciliate; palpi normal; halteres tipped with black. . . . P. srwPLiciPES, nov. sp. (3). 
(i) Platypalpus glacialis, nov. sp. — Male. Length 2.3 mm. Body black, legs including the coxa 
yellow, notum not pollinose but finely pubescent between broad dorsocentral glabrous rows, spur of middle tibiz 
not developed, tarsi not annulate, antennae black, the third joint short, ovate, about one-fourth the arista in length, 
palpi whitish and large, pygidium large, globose and subshining, crossveins approximate, the posterior nearly 
transverse.  Occiput with olivaceous pollen, its upper hairs golden, ocellar bristles piceous, front lightly dusted, 
short, its sides diverging, face very narrow, gray, epistome polished, proboscis short, piceous: first and second 
antennal joints fused, third as long as deep.  Notal pubescence evident but fine and rather sparse, humeri and sides 
of notum with light pollen, lateral bristles yellow, the humeral short, sternopleure polished. ^ Abdomen shining, 
nearly bare, right dorsal valve of the pygidium deeply bifid, left valve small and triangular. Legs slender, front 
femora weakly ciliate, middle femora with about twenty black setule in the anterior row and about sixteen longer 
setule in the posterior row, no yellow bristles, middle tibiz about seven-eighths as long as the femora, tarsi 
vaguely becoming dusky apically.  Calypteres, fringe and halteres yellow. Wings hyaline, two and a half times 
as long as broad, veins thin and  blackish, costa black at end of first vein, costal sections proportioned 
72:5:3.5:1,third vein ending at wingtip, very slightly converging toward fourth, crossveins separated by less than 
the length of the anterior and by one-half the length of the posterior, located at two-fifths the wing-length, sections 
of the fifth vein proportioned 2 : 3: 5, anal crossvein straight, evanescent apically and reflexed at an angle of 
fifty degrees, anal vein faintly impressed, anal angle weak. 
Female. Last two segments ochraceous, styles slender. 
Two: specimens, Glacier National Park, Montana, August 14, 1916 (Melander). 
(2) Platypalpus pubescens, nov. sp. — Male. Length 3 mm. Body black, the venter yellowish, legs 
including the coxa yellow, notum not pollinose but uniformly and rather densely pubescent, spur of middle tibize 
undeveloped, tarsi not annulate, antenna black, the third joint one-fourth as long as the arista, palpi brownish, 
pygidium large, globose and pollinose, crossveins approximate, the posterior nearly transverse.  Occiput finely 
dusted, its upper hairs dusky, vertical and  ocellar bristles black, front finely pollinose, two and a half times 
as long as wide at the middle, face and epistome shining black, proboscis short and brown, palpi brownish 
yellow ; antenna three jointed, the third joint conical, scarcely longer than wide. Extreme sides of the mesonotum 
and the pleure white pollinose, disc of notum uniformly, closely and conspicuously white-pubescent, lateral bristles 
yellow, no humeral, one pair of rather distant scutellars; sternopleurz polished except the extreme upper part. 
Abdomen not tapering, shining, its hairs rather dense. dorsal valve large, circular and not fringed.  Trochanters 
tipped with black, front femora not ciliate, middle femora robust, with about thirty minute black setule in the 
anterior flexor row and twenty-one setule in the posterior row, the latter flanked by a few yellow setze, middle 
tibia almost three-fourths the femora, only an indication of the spur present, tarsi gradually becoming dusky 
toward the tip.  Calypteres and knob of halteres whitish, fringe and root of halteres luteous. Wings hyaline, 
two and a fourth times as long as wide, veins narrow and  piceous, sections of the costa proportioned 
6:3.5:2.5 : 1, third vein gently recurved and ending at the wing-tip, first posterior cell widest at the apex, 
last two sections of the üfth vein subequal, anal crossvein straight, reflexed at an angle of fifty degrees, ends of 
the anal vein evanescent. 
Female.  End,of abdomen not ochraceous, the styles tumid. 
Seven specimens, Union Flat, near Pullman, Washington, July 16, 1916 (Melander). 
(3| Platypaipus simplicipes, nov. sp. — Male. Length 2 mm  Blackish, largely shining, legs yellow, 
without evident setze, crossveins meeting. Head globular, occiput lightly dusted, subshining, front shining, 
moderately wide, broadening above. face short, black; palpi elongate oval, as long as the face, yellow, with a 
few marginal white setulze, proboscis brown; antenne three-jointed, the last joint short-ovate, scarcely longer than 
broad, one-third as long as the rather pubescent arista; vertical bristles small. Mesonotum uniformly pubescent, 
no discal setule, no humeral bristle, one notopleural, one supraalar, one prescutellar, four scutellar, the outer 
ones smáll; upper half of the pleure lightly pruinose, sternopleure and hypopleure shining ; abdomen shining, 
the pygidium globular and puberulent, the fringe of the upper valve long but fine. Legs slender, front femora 
