334 DIPTERA 
Third and fourth veins subparallel; antenne black. . . . P.Porrrus, 
Var. NITENS, nov. var. (1). 
66. Legs reddish yellow, tarsi becoming piceous apically . . . P. vtrrarUs, nov. sp. (2). 
Middle femora above and hind femora ringed preapically 
with black, tarsi black exceptat base . . . . . . . P.virTATUS, 
Var. PERIMERUS, nov. var, (3). 
67. Spur of the middle tibiz shorter than thediameterofthetibia. . .— . . . . . . . . . 68. 
Spur of the middle tibiz at least as long as the diameter of 
ihn.  . 0o o rn a Mc D PUN IU oW 
68. Crossveins meeting and transverse; spur of the middle tibiae 
minuteor wanting. .. 3. 4» (i x» ave dc Qu NEIN ICI 
Posterior crossvein more or less oblique and located beyond 
the anterior; at least base of the antennz yellow, third 
joint ovate, less than twice as long as wide; bristles 
yellow; spur of the middle tibiz small but evident, middle 
femora ciliate beneath; anal cell incomplete . . . . Auer DL UA DIE Ert E EL RH 
69. Abdomen more or less pollinose; femora not thickened, the 
middle femora with r2 setulz in the posterior row and no 
bristles; base of the antennz yellow, the third joint ovate ; 
pleure entirely pruinose . . . . . . . . . . . P.caNvus, Melander, 
the crossveins equal to the anterior crossvein, sections of the fifth vein proportioned r: 1.5 : 1, anal crossvein at 
an angle of seventy-five degrees, evanescent toward its end, anal vein indicated only by a very íaint fold beyond 
the anal crossvein, marginal cilia very short. 
One specimen, presented by J. M. Aldrich, who collected it at Sierra Morena Mountains, California, 
April 3, 1906. 
(i) Platypalpus politus, var. nitens, nov, var, — Several specimens differ from the preceding form in 
having the antennz black and the third and fourth veins nearly parallel. The represent the following localities : 
Redwood City, California (J. M. Aldrich); Kerr County, California (W. M. Wheeler); Atherton, Missouri 
(C. F. Adams), and Washington, D. C. (Knab and Malloch). 
(2) Platypalpus vittatus, nov. sp — Length 2.9 mm. x Front cinereous, its sides sibpacullit fus and aplspud 
white-pollinose; palpi black, the exterior side overlaid with white, oval, one-third as long as the black proboscis; 
antennz black, three-jointed, the base of the second joint shining, the third joint elongate-ovate, nearly three times 
as long as broad, short-pubescent beneath, the arista two-fifths longer than the third € one pair each of dusky 
vertical and ocellar bristles. Thorax with a shining black stripe on each side of the middle between the 
acrostichal and dorsocentral rows, expanding laterally on the posterior part of the notum towards the base of the 
wings, elsewhere with cinereous pollen on a black ground, the pleurz whiter, sternopleural spot large; abdomen 
polished black, sparsely hairy, pygidial valves inconspicuous, subdorsal pits prominent. Legs testaceous, base of 
the posterior coxa black, front femora biseriately ciliate beneath, front tibie as thick as the middle ones, middle 
femora yellow-setose in back of the rather coarse black setulz, middle tibie two-thirds as long as their femora, 
their spur strong and black, tarsi blackish beyond the base.  Veins reddish brown, costa not thickened, its second, 
third and fourth sections proportioned 5 : 3 : r, third and fourth veins slightly curving, the first posterior cell 
widest near the middle, posterior crossvein at the middle of the wing, rather oblique, twice as long as the 
anterior which is equal in length to the space between the crossveins, sections of the fifth vein  proportioned 
0.8: r1 : I, base and apex of the anal vein wanting, the anal crossvein forming an angle of seventy degrees, 
evanescent, marginal cilia as long as the anterior crossvein, 
Five specimens, Converse County, Wyoming, received from Professor Wheeler, and Omak, Washington 
(Melander) In two of the specimens the shining vittz of the mesonotum are separated by a pollinose stripe 
from the supra-alar spot. 
(3) Platypalpus vittatus, var. perimerus, nov. var, — Seven specimens from Chin and Bow Slope, Alberta, 
collected by Walter Carter from alfalfa, May 3o — June 5, 1923, differ from the preceding in having the legs marked 
with blackish. 'This darkening is variable, in its extreme extent forming a dorsal steak on the anterior femora, a 
broad preapical ring on the posterior femora, the hind tibiz piceous and all the tarsi black. The lighter colored 
individuals lack the dorsal streak of the front femora, the preapical ring of the middle femora, and their hind 
tibie are blackened only at the extremity. Types in Canadian National Museum and author's collection. 
