FAM. EMPIDIDE  - 343 
103. Abdomen strongly fasciate with bands of pollen; first 
posterior cell widest at middle, its veins recurved . . . P. FASCIVENTRIS, nov. sp. (1). 
Abdomen shining; third and fourth vein parallel . . . . P.PosrrosrrTUS, nov. sp. (2). 
104. Third amtennal joint short-ovate, one-third to one-half as 
long as its arista; crossveins separated by more than the 
length of the anterior crossvein, base of the anal vein 
present but weak; epistome pruinose; front tibie with 
DurdisscnesensopaEda wc Mure M KE qued e dat e ds IO, 
'Third antennal joint long-ovate, more than half the length 
of arista; crossveins separated by less than the length of 
the anterior crossvein, base of tlie anal vein wanting: front 
Hle wiuHweakor-no.extensor brisesz; s woe Eu sw eit este mde. Iob. 
105. Antenne black; tarsi strongly annulate and not dilated; 
front tibia with evident black extensor sete, middle femora 
With yellow sete&un front 002910 24S os 7 EoN. P. TRIVIALIS, Loew. 
Antenne red with black tip; middle tarsi Qf black, the 
metatarsi dilated into a flat disk, tarsi Q weakly annulate, 
the middle pair blackish; extensor bristles of front tibize c 
yellow, of Q black; middle femora without yellow sete 
indront:paslpivelow c4 S ue V voreco.- c. P.nDISCIFER, Loew. 
(1  Platypalpus fasciventris, nov. sp. — Male. Length 3 mm. Body black, legs yellow, notum closely 
golden pollinose, bristles yellow, ábdomen with pollinose fascia, lower third of sternopleurz polished, tibial spur large, 
tarsi weakly annulate, front tibie without bristles, posterior crossvein oblique and located at the middle of the wing. 
Occipital hairs abundant and white, vertical bristles short and yellow, front nearly four times as long as broad, 
closely gray pollinose, its sides little diverging, face gray, epistome bare, proboscis black, palpi yellow, with 
conspicuous white hairs; antennz black, the outer joint pyriform, twice as long as deep and less than one-half as long 
as the rather strong arista. Four yellow setze grouped around the supra-alar bristle, humeral small, two small lateral 
scutellars in addition to the central pair, setule in four irregular rows, pollen of pleure gray. Abdominal fascie of 
gray pollen occupying the basal half of each segment and expanding laterally, seventh tergite entirely pollinose, ventral 
segments shining, abdominal hairs pale and scattering, pygidium not globose, small, the dorsal valves projecting 
backward, the left dorsal valve with a close fringe of downward-directed, nearly straight, yellow hairs. Coxe yellow, 
front femora of nearly same diameter as the middle pair, weakly ciliate beneath, middle femora with about eighteen 
setule in each flexor row, those behind scarcely longer, the row flanked by a few weak outstanding yellow setze, middle 
tibize three-fourths the length of the femur, the spur longer than the diameter of the tibiz and tipped with black, 
extreme tips of the tarsal joints slightly browned. Calypteres, fringe and halteres yellow. "Wings hyaline, anal angle 
well developed so that the anal vein lies midway between the fifth vein and the margin, third vein gently recurved to 
end at the wing-tip, first posterior cell widest at the middle, fourth vein sinuous, sections of the fifth vein 2 : 3 : 2, 
distance between the crossveins nearly equal to the anterior crossvein, anal crossvein almost perpendicular, its outer 
half abruptly faint, anal vein vanishing basally. 
Holotype, Klickitat River near Glenwood, Washington, June 27, 1917 (Melander). 
(2) Platypalpus postpositus, nov. sp. — Male. Length 1.8 mm. Mesonotum almost completely covered 
with golden pollen, the black ground color hardly showing through, legs yellow, the tarsi a little dusky apically, tibial 
spur long and slender, posterior crossvein beyond the middle of the wing, oblique, costa thickened between the first 
and third veins. Front cinereous, rather narrow, face white-pollinose, epistome shining black; palpi white and with 
white bristles, proboscis black; antenne black, two-jointed, the last joint apparently short-ovate, the arista three times 
as long as this joint; one pair each of vertical and ocellar bristles yellow, hairs of lower occiput moderate and white. 
Thoracic bristles yellow, one humeral, two notopleural, one supraalar, one dorsocentral, one pair of long and one of 
short scutellar bristles, two definite rows of acrostichal setule; pleurz silky white, a small oval sternopleural space 
glistening; abdomen subshining, its hairs white, long but rather sparse, fringes of the pygidium small  Coxa pale 
yellow, flexor hairs of the anterior femora longer, the middle femora with a posterior row of about fourteen yellow setae 
in addition to the two rows of minute setule, spur of the middle tibizc a little longer than the diameter of the tibia, 
acute and tipped with black. Veins yellow at the base, darker apically, crossveins separated by the length of the 
anterior crossvein, third and fourth veins parallel, sections of the fifth vein proportioned o.8 : 1 : r, base of anal vein 
wanting, marginal cilia equal in length of the anterior crossvein. 
One specimen, Almota, Washington, June 24, 1911 (Melander). This species resembles cellaris but has black 
antenne, a longer tibial spur, and less setulose thorax. 
