320 DIPTERA 
13. Slender; legs including the coxze entirely black; pleure and 
front coxze pruinose; discal dorsocentrals present . . . P. TACHISTIFORMIS, nov. sp. (1). 
More robust; legs piceous, the front coxe, the middle 2 : 
trochanters and the tibie yellowish brown; pleure and 
front coxze silky-pollinose; bristles minute. . .. . . . P.SERICATUS, nov. sp. (2). 
14. Anterior femora ciliate beneath; posterior crossvein beyond 
the anterior; middle tibiz with a sharp spur ; four scutellar 
brédes.. 0. 2 02. v. V eor s NIS TALIA EP M MM EP E ME 
Femora not ciliate; crossveins meeting; no tibial spur; third e. 
antennaljoint oval; two scutellar bristles . . . . . . P.coNrIGUUs, nov. sp. (3). - 
with a few fine black hairs. Thoracic dorsum with golden pollen, bristles black, one humeral, one notopleural, 
one supraalar, one small prescutellar and two scutellar bristles; pleurz more closely but finely pollinose, the 
sternopleurz largely shining; abdomen shining, white-hairy, pygidium large. Spur of the middle tibie moderately 
large, black, the postero-flexor edge of the middle femora with thirteen black spine-like bristles, the anterior side 
of the middle tibiae also with smaller more scattered black bristles, under side of front femora with small pale 
separated cilia. Costa greatly thickened at the confluence with the first vein, the second, third and fourth sections 
proportioned 4 : 3 : 1, third and fourth veins subparallel, crossveins meeting, the posterior transverse, anal vein 
weak but uniformly perceptible, anal crossvein forming an angle of sixty degrees, abruptly attenuated beyond its 
basal third, 
One specimen, Stanford, California, January 27, 1906, collected by Dr. J. M. Aldrich, 
(1) Platypalpus tachistiformis, nov. sp. — Female. Length 2 mm. A slender black species that 
resembles certain species of Tackyempis, but has a distinct anal crossvein and a spur on 
and thorax cinereous pollinose becoming pruinose on the pectus and pleurz, legs 1 
brown.  Palpi elliptical, one-half as long as the proboscis, black but thickly overlaid with white pruinosity and - 
with a few white hairs; first antennal joint entirely wanting, the last joint globular, scarcely longer than wide, 
the rather thick arista one-third longer than the antennz; the ocellar and two pairs of vertical bristles rather strong 
and blackish,  Bristles of the thorax prominent and yellow, four dorsocentrals, six rows of acrostichals, 
scutellar bristles; sternopleurz: with a small rounded glabrous spot; sides of the first abdominal segment pollinose, 
the last three segments opaque brown pollinose, Front femora rather thick, middle femora loosely 
short bristle-like yellow hairs on the postero-flexor edge, front coxz with abundant golden bristles. 
swollen, its second, third and fourth sections proportioned 2,5 : 2,5 : 1, third and fourth veins parallel, anterior 
crossvein slightly beyond the oblique posterior crossvein, sections of the fifth vein subequal, anal 
complete, forming an angle of seventy degrees, anal vein indicated by a fold. 
Two specimens, Harlowton, Montana, June 14, 1913 (Melander). 
(2) Platypalpus sericatus, nov. sp. — Female. Length 2 mm. Black, legs piceous, the front 
apex of posterior coxa, base of femora, apex of front femora, and the tibiz yellowish-brown. Third antennal join 
oval, one-half longer than wide, the arista one and two-thirds times as long as the antennz; face, front and palpi 
white-pruinose, the latter one-third as long as the proboscis; ocellar bristles brown.  Dorsum of the thorax with 
yellow pollen, the minute sparse hairs and the bristles yellow, one humeral, one notopleural, one 
four scutellar, the lateral pair small; pleurz and front coxa with silky whitish-yellow pollen, the sternop: 
largely shining; abdomen polished. Anterior femora ciliate with yellow hairs, spur of the middle tib 
strong. First vein swollen on entering the costa, the second, third and fourth sections of the costa proportioned 
3.2: 2.5 : 1, posterior crossvein oblique, located beyond the anterior a distance equal to the length of the an 
crossvein, fourth and fifth veins parallel, fifth vein interrupted before reaching the margin; base of anal 
completely wanting, the remainder indicated as a fold. 
One specimen, Nelson, British Columbia, July, 1910. 
(3) Platypalpus contiguus, nov. sp. — Length 2 mm. Black, largely shining, legs black, crossveins 
contiguous. Third antennal joint short-oval but broad, the arista not much longer than the antennz; face and 
front cinereous pollinose; palpi small, one-fourth as long as the proboscis, blackish ; cephalic hairs blackish. 
Humeri, notopleural sutures, scutellum and metanotum cinereous pollinose, otherwise the notum is polished, the 
bristles and hairs yellowish, three humeral hairs, three notopleural, one supraalar, one scutellar, two pairs of 
dorsocentral bristles, acrostichals biseriate and small; pleurz white-pruinose, the sternopleurz polished ; abdomen 
shining, the pygidium rather erect. Posterior coxe and femora and the tarsi apically, black, femora not ciliate, 
no tibial spur. Costa only slightly swollen at the confluence with the first vein, the second, third and fourth 
sections proportioned 2.5 : 1.6 : r, third and fourth veins parallel, anal crossvein evanescent, forming an angle of 
fifty degrees, anal vein indicated only by a fold in its outer part. 
Bear Lake, British Columbia, 7000 feet altitude, July 29, 1903, collected by R. P. Currie for the U. S. 
National Museum. 
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