FAM. EMPIDID/E 327 
Face as broad as the front; proboscis brown to black ; terminal 
segments of the Q abdomen shining ; anterior femora more 
orlessthickened; notal hairs short and verysparse. ... . . 4. 5 - 0o HIR 44. 
44. Penultimate segment of Q abdomen long and swollen ; 
pygidium enormously enlarged, nearly as bulky as the 
remainder of the abdomen; proboscis brown; third joint 
of the antenna ovate, shorter than the arista; middle tibize 
with'a pronoBnced SpuE. 3: 79 4070 Qc uu sur. Du scu P SATYRIACUS, DOVSD- (X). 
Terminal segments of the Q abdomen small; proboscis black ; 
middio hbupaoUMOoSEwIUES Small spnE Eid ee d devel ab ete uns v eese 9 
45. First posterior cell narrowed apically, about one-third the 
costal margin of the submarginal cell in width; styles of 
Q abdomen three times as long as wide; incisures not 
dHerengated-. "ou ccn MELIA CON wh P. copLATERALIS, noy; 8p..(2). 
First posterior cell not narrowed, apically about one-half the 
costal side of the submarginal cell; styles five times as long 
middle tibiz five-sixths as long as the femora, spur minute and yellow.  Halteres, calypteres and root of wings 
very pale yellow, wings three times as long as wide, costal sections proportioned 5:4:3:1, first posterior cell 
ending at tip, its veins nearly straight and parallel, sections of the fourth vein proportioned r : 2, of the fifth vein, 
3:4:8, posterior crossvein transverse, slightly in advance of the anterior, anal vein weak but complete. 
Female. Fourth tarsal joint apically infuscated. ^Ovipositor shining except on incisures, styles four times 
as long as wide. 
Male type from Nahcotta, Washington, May 24, 1917; female from Vashon, Washington, May 28, 1917; 
five paratypes from Shelton, Quilcene and Piedmont, Washington, July (Melander). 
(1) Platypalpus satyriacus, nov. sp. — Length 2 mm. Readily distinct by the swollen genitalia of both 
sexes; related to /ateralis, but differing in the broader face, longer arista, pronounced tibial spur and sparse short 
notal hairs. Black, with a castaneous tinge, head opaque gray pollinose except the shining epistome; face short 
and about as broad as the front; palpi yellow, proboscis dark castaneous; antenne yellowish at the base, the third 
joint darker toward the tip, conical, two to two and one-half times as long as broad, not hairy, and shorter than 
the rather thick arista; vertical hairs yellow. Center of the mesonotum broadly shining, sides and pleure whitish 
pollinose, sternopleurz largely shining, bristles yellow. Abdomen of male with long hairs, especially apically, the 
genitalia greatly enlarged, in bulk about equal to the remainder of the abdomen, the penis visible as a strong 
black hook, the left valve strongly emarginate on the right-hand edge and apically fringed; hairs of female abdomen 
normal, incisures ochraceous, last tergite elongate, as long as two or three of the preceding segments, overlapping 
the ovipositor and shining blackish brown, styles short, brown. Legs yellow, anterior femora moderately robust, 
about sixteen black setule in the posterior row of the middle femora, middle tibize five-sixths as long as their 
femora, with an acute yellow spur slightly shorter than the diameter of the tibia, last tarsal joint darkened- 
Wings very long, veins yellow, third and fourth veins gently converging apically, second and third sections of 
the costa of the male somewhat thickened, the second, third and fourth sections proportioned 1i.2:1:0.2, sections 
of the fifth vein 1 :1.2:2.2, marginal cilia of male equal to the anterior crossvein in length, of the female short. 
Four specimens, Ungava Bay of Hudson Straits, Northern Labrador, collected by L. M. Turner:a pair 
deposited in the U. S. National Museum. 
(2) Platypalpus collateralis, nov. sp. — Female. Length 2 mm. Closely related to lateralis Loew, but 
the latter differs in having a narrowed face and front, yellow proboscis, the last two segments of the female abdomen 
ochraceous, the femora more slender, no tibial spur, and long mesonotal hairs. Black shining, sides of the thorax 
white pollinose, legs yellow, tibial spur short, tarsi becoming dusky broad at tip, crossveins meeting and transverse; 
sides of the front parallel, face quite as wide as the front, proboscis black, mesonotum with sparse short whitish hairs, 
abdomen entirely shining black, fourth vein gently converging toward the third. Front, face and occiput opaque gray 
pollinose, the face very short, epistome shining; palpi white; base of the antenne brown (the last joint lacking in the 
specimens before me); vertical and ocellar bristles long and whitish. Humeri and sides of the mesonotum whitish pollinose 
like the pleure, the sternopleurz largely polished, bristles whitish; styles about three times as long as broad, black. 
Anterior femora somewhat thickened, the middle pair with about fifteen black setule in the posterior row. Calypteres 
with a yellow fringe. Wings nearly hyaline, with pale veins, second section of the costa somewhat swollen, the second, 
third and fourth sections proportioned 5: 3: rz, third vein straight, ending at the wing-tip, sections of the fifth vein 
proportioned r : r.5 : 2.5, marginal cilia shorter than the anterior crossvein. 
Alaska, several places : Harriman Expedition, 
