FAM. EMPIDID/E 323 
25. Mesonotum uniformly pollinose; third antennal joint tipped 
with black; anal crossvein and anal vein distinct; face as 
long as the front; middle tibiae much shorter than the 
fRngs OMNEM oce ei seio ones da BELAVIROSTRIS, J:06 WV 
: Var. VITTIGER, nov. var. (t1). 
Sides of the notum pollinose; antennz yellow; anal crossvein 
and anal vein very faint; face much shorter than the front; 
middle tibize nearly as long as their femora. . . . . P. MELANOGASTER, nov. sp. (2). 
26. Thorax densely yellow-pollinose; antennz; wholly or quite 
sellos mid emo RUE s 4 oS INR AL A .alcE Cei s ce eg Ure AT 
Thorax shining or subshining; third antennal joint usually 
dasbaedi ME peur p Mut Md Mac ica auque Las 
27. Posterior crossven beyonlid the'antenor: tarsr yellow. o0 ole os e ow 28. 
Crossveins meeting; tarsi narrowly annulate; proboscis 
xelowusc c«m mnc M NEN C Ei cu UPIMPHXUS,«Melander. 
28. Proboscis yellow ; antennz entirely pale yellow; abdomen 9 
sometimes with a narrow median vitta. . . . . . . P.vrmsurUs, Melander. 
Proboscis black; third antennal joint tipped with black; 
middle segments of the abdomen black. . . . . . . P.ocHmicorus, nov. sp. (3). 
(1) Platypalpus flavirostris, var. vittiger, nov. var. — Male. Length 3.6 mm. Head black, cinereous 
pollinose, mouth-parts and base of the antenne yellow, the third antennal joint about one-third the arista, 
elongate-oval, mesothorax lightly pollinose over an ochraceous ground, a median blackish vitta about one-fourth 
the width of the notum; base of the pollinose scutellum narrowly blackish; most of the sternopleurze smooth. 
Abdomen blackish, shining. Legs yellow, the last tarsal joint blackish, middle femora with five yellow bristles 
and twenty-six black setulae on the antero-lexor edge and nineteen bristles on the postero-flexor edge, spur of 
middle tibia small Wings yellowish hyaline, the veins pale, crossveins touching, the posterior nearly transverse, 
third vein ending at the wing-tip, reflexed and parallel with the fourth, under side of the second basal cell 
slightly shorter than the ultimate section of the fifth vein, anal vein rather weak and forming an angle of eighty 
degrees. 
Type, Douglas, Alaska, August 7, rigor, collected by the late E. L. Jenne. A series of similar specimens 
was taken by the writer in Glacier National Park, Montana, August 14, 1916. A dozen additional specimens from 
the same locality lack the mesonotal vitta and approach the typical form of flvirostris. 
Differs from  mesogrammus Loew in having the thorax pollinose, not shining, the third antennal joint black 
and the middle femora more slender and with only the usual two rows of black setula beneath. In mesogrammus 
there is an additional row of about ten long pale bristles along the postero-flexor edge. 
(2) Platypalpus melanogaster, nov. sp. — Length 1.8 mm. Head and abdomen black, thorax yellow with a 
median castaneous vitta, legs pale yellow. ^ Occiput lightly cinereous, its hairs white; antennz inserted low down on the 
head, the front about twice as long as the face; two pairs of ocellar bristles but apparently no vertical ones ; front moderately 
broad, its sides slightly diverging above, minutely but densely whitish pubescent rather than pollinose, face one-half 
as broad as the front, whitish, epistome black; proboscis reddish; antenne short, yellow, the third joint short- 
pyriform, apparently ovate but really pointed, the arista brown, rather coarse, two and one-half times the actual 
length of the third joint. Thorax short, quadrate, broader than the head, humeri large, squarish, sides of the 
notum thinly white pollinose, disk polished and nearly bare; pleurz lightly white-pollinose, the sternopleurz largely 
shining; abdomen shining, blackish, its hairs sparse, the pygidium moderate in size, the dorsal valve short and 
rugose apicallyi; abdomen of female tapering. the last two segments opaque ochraceous, styles slender and yellow. 
Legs long and slender, simple, middle tibize five-sixths as long as their femora, the flexor setule of the middle legs 
rather long, thin and yellow, no extra sete, no tibial spur. Veins pale but towards the apex becoming brownish, 
costa not thickened, its second, third and fourth sections proportioned 3 : r.8 : r, third and fourth veins rather 
widely separated, straight and parallel, posterior crossvein transverse, located a little before the anterior and at 
three-sevenths the wing length, fifth vein very long, its sections proportioned 0.5 : 0.5 : r, anal crossvein perpendicular, 
very faint, anal vein very faint and close to the margin. 
Three specimens; Ungava Bay, near northern Labrador, collected by L. M. Turner. Type in the U. S. 
National Museum. 
(3) Platypalpus ochricollis, nov. sp. — Female. Length 2 mm. Head black, densely cinereous polli- 
nose, the bristles pale yellow, proboscis black, palpi pale yellow, àntennz yellow, the lanceolate third joint tipped 
with black. Thorax ochraceous, overlaid with dense whitish pollen, sternopleura with a small glabrous spot; 
