336 DIPTERA 
74. Thoracic bristles black; tarsi piceous beyond the base, middle 
femora with anterior black bristles and setose beneath on 
the postero-flexor edge (P. Porretus, Melander) . . . . . . . . ... .. . . 75. 
Thoracic bristles yellow; last three tarsal joints strongly 
annulate, middle femora without black bristles and biser- 
iately setulose beneath . . . . . . . . . . . . P. v&Lox, nov. sp. (1). 
75. Abdomen completely shining. . . . . . . . . . . P. PORRECTUS, css S. str. 
Base ofthe abdominal segments poliinose. . . . . . . P. PORRECTUS, 
Var. SUFFASCIATUS, nov. var. (2). 
76. Abdomen pollinose and red; front tibie swollen and ciliate ; 
front tarsi annulate; thorax white-polinose . . . . . P. VrERECKI, Melander. 
Abdomen black and rarely with pollen; tibie notswolen . . . . . . . . . . . . 773. 
77. Proboscis yellow; tarsi yellow; white-pollinose species . . P. TENELLUS, Melander. 
Proboscisblak . . . . 3 : ; x pl... cca ce uS o EE 
78. Mesonotum densely golden vilkaaet, MUeect with the 
silvery pleurz; palpi orbicular, not hairy; costa not 
swollen; tarsi strongly annulate; abdomen with lateral 
pollinose triangular spots . . . . . . . . . . - P. BALLUCATUS, nov. sp. (3). 
(1) Platypalpus velox, nov. sp. — Male. Length 2 mm. Black, cinereous, bristles yellow, legs yellow, the 
last three tarsal joints strongly annulate, tibial spur small, femora not setose or ciliate, third antennal joint elongate, 
arista short, crossveins meeting. Occiput, front and face cinereous, front rather narrow, its sides diverging above, 
epistome black; antennz! two-jointed, black, the outer joint subulate, over three times as long as wide and nearly 
twice as long as the arista. One pair each of the usual thoracic bristles, setulae very sparse, the pollinose coating 
whitish, sternopleurz glabrous except the front and upper edge; pygidium globose and small. Posterior coxz slightly 
brownish at the base, front femora nearly as thick as the middle ones, beneath with fifteen short pale cilia, middle 
femora not bristly, beneath biseriately setulose, the setulze of the posterior row, twenty in number, scarcely longer than 
those of the anterior row, middle tibiz nearly as long as their femora. "eins brown, costa thickened at the end of 
the first vein, its second, third and fourth sections proportioned 3 : 2 : r, crossveins nearly transverse, located at 
three-sevenths the length of the wing, the anterior three-fiffhs as long as the posterior, third and fourth veins 
subparallel, the first posterior cell a little the widest at two-thirds its length, ending at the apex of the wing, sections 
of the fifth vein proportioned 0.4 : 0.6 : 7, anal crossvein thin, at an angle of sixty-five degrees, anal vein faint, 
marginal cilia short. 
One specimen, Kettle Falls, Washington, May 3, 1912. 
(2 Platypalpus porrectus, var. Suffasciatus, nov. var. —  Differing from forrectus Melander in that the 
sides of the first segment of the abdomen and the sides and bases of the subsequent segments are cinereous pollinose, 
leaving the lateral pits conspicuously shining. 
Boulder, Colorado (Cockerell); Alma, California (Aldrich). 
(3) Platypalpus ballucatus, nov, sp. — Female. Length 2.5 mm. Mesonotum densely covered with golden 
pollen, sides of the abdomen pollinose, antennz reddish yellow. Front densely golden pollinose, its sides parallel, face 
and epistome silvery, palpi yellow, broadly orbicular, pubescent only at the edge, proboscis black; third joint of the 
antennz ' ovate, scarcely longer than wide, its arista black; one pair of vertical and one of ocellar bristles yellow, 
lower occipital hairs dense and whitish. One humeral, one notopleural, one supraalar, two scutellar and two 
dorsocentral bristles yellow, setulze small and sparse; pollen of the pleurze dense and white, a small rounded sternopleural 
glabrous space ; abdominal segments with lateral tiiangular pollinose marks which are broad in front and taper obliquely 
behind, the middle segments with two prominent lateral pits, venter pollinose. Legs including the coxze yellow, the apices 
of the tarsal joints narrowly blackish, front femora with about thirteen pale cilia in each of two flexor rows, black setulae 
of middle legs minute, posterior-flexor edge of the middle femora with ten yellow setze, the anterior edge loosely setose, 
middle tibize three-fourths as long as their femora, their spur shorter than their diameter, acute, and tipped with black, 
Veins pale, crossveins at the middle of the wing, the postérior crossvein somewhat oblique, located beyond the anterior 
crossvein the length of the latter, costa not tickened, its second, third and fourth sections proportioned 3.8 : 2.4 : 1, third 
vein straight, ending just before the tip of the wing, subparallel with the slightly undulating fourth vein, underside of 
the second basal cell twice as long as the last section of the fifth vein, anal crossvein at two-fifths the length of the basal 
cell, attenuated apically, forming an angle of eighty degrees, base of the anal vein wanting, marginal cilia short. 
Two specimens, Spokane, Washington and Chicago, Illinois (Melander), 
