FAM. EMPIDID/E 75 
Ic IMesobvengallofpypidiumHattened. .. . 5-3 90 Roo LI IK 
Tines of pygidial fork more orlesscylindrical . . . . . iux Mene mu E err Mns i. 
11. Pygidial fork widely and shallowly excised, the tines short trian- 
gular ; abdominal hairs pale ; bristles of hind tibie fine. . . B. BREVIFURCA, nov. sp. (1). 
Pygidial fork narrowly and deeply excised, the tines long and 
blunt; abdominal hairs of male black; atleast four outstanding 
bristles on hind tibie . . . D NIME cT B. PLEIPES, LOOW: 
12. Tines of pygidial fork very long iid thin Mr MM EL S NE TEN VU QRNCN VU LT SIN Rd. 
diues pusidie [DIE SBOPter atid stoutet^ — 2 5. cosetuo x edd eo e rie io ide 
13. Pubescence black ; third antennal joint more than twice as long as 
wide, its elongate base tapering apically. . . . . . . B. ANGUSTIFURCA, nov. sp. (2). 
Hairs of abdomen and femora for most part pale yellow ; third 
antennal joint less than twice as long as wide, its ovate base 
distinct from the tubular apex . . . . . B. FURCIFER, nov. sp. (3). 
14. Pygidial fork narrowly U-shaped, its tines tioped with microscopic 
hair (if tines are stubby, see wvens) . . . P. xu coe UMEN 10 P5. 
Pygidial fork broadly U-shaped, its tines ubped with a bo oir ; 
halteres of both sexes dark ; base of third antennal joint ovate, 
Ane Du. v ouuesqu I cou M UE LES ^r BU LoNGIPES, Loew. 
(1) Bicellaria brevifurca, nov. sp. — Length 3mm. Black with faint brown coating, hairs and bristles black, 
the hairs of the abdomen pale. Facets of eyes moderately large above, about sixteen along the line of contiguity ; 
under side of third antennal joint gently rounding into the apex, arista about two-thirds as long as this joint. Notum 
velvety brown, the anterior hairs short, four scutellars. Ventral fork of pygidium flat, M-shaped in outline. Hind femora 
rather short-ciliate, eighteen or more sete in anterior extensor row and twenty or more in anterior flexor row; hind 
tibiae subclavate, about twice as broad at end as at base, extensor bristles fine and uniform ; hind metatarsi slightly 
thicker than the following joints. Halteres black. "Wings infumated in male, grayish in female, stigma brown, fork 
of fourth vein usually open, the pedicel shorter than the fork. 
About one hundred specimens, alpine parks of Mount Rainier, Washington, July to September. 
(2) Bicellaria angustifurca, nov. sp. — Male. Length 3.2 mm. "Very black, opaque ; third antennal joint 
elongate and large, two times as long as deep, tapering from the rounded base to the apex without tubular tip, arista 
two-thirds the length of this joint. Hairs and bristles entirely black; pygidium small, ventral fork polished, very 
deeply cleft, the tines unusually long, slender, parallel on basal half and then diverging. Seta of both upper and 
lower surface of hind femora very long aud abundant, about twenty-one in upper anterior row ; hind tibie gradually 
but decidedly clavate the extensor sete uniform and moderate, hind  metatarsi but slightly thickened.  Halteres 
thickened, wings very strongly infumated almost blackish brown, the stigma scarcely differentiated. 
Female. Not opaque black but thinly coated with brown dust on notum. Abdomen subshining, pleure 
cinereous, abdominal hairs brownish, last segment shining. 
Types, Olympia, Washington, 22 June, 1920; six paratypes; Bellingham, Washington, Mount Hood, Oregon, 
Priest Lake and Moscow, Idaho (Melander). 
(3) Bicellaria furcifer, nov. sp. — Length 2.75 mm. Black with faint brown coating, hairs and bristles 
generally black, those of lower occiput, abdomen and coxe and base of femora pale. Facets moderately large above, 
about sixteen in line of contiguity of the eyes ; third antennal joint about twice as long as deep, the ovate base distinct 
from the tubular apex, arista about half the length of the third joint. Notum subshining, the hairs short in front, 
four brownish scutellar bristles; hairs of abdomen long.  Tines of pygidial fork very long and thin, tipped with a 
microscopic hair. About fifteen setze in upper and lower rows on hind femora ; hind tibiz subclavate, about three 
times as wide toward apex as at base, with two or three of the extensor hairs longer than the others ; hind metatarsi 
scarcely thicker than the next joint. Halteres of male black, of female yellowish brown ; hairs of calypteres brownish. 
Wings grayish hyaline, stigma brown, fork of fourth vein usually complete and shorter than its pedicel. 
Type and allotype, Upper St. Regis River, Montana, 28 July, 1918. Nine paratypes, Yellowstone Park, several 
places, Wyoming ; Jefferson Island and Perma, Montana; Craig's Mountain, Idaho ; and Nelson, British Columbia, 
all collected by the author. 
