332 ' DIPTERA 
60. Mesonotal hairs sparse; two single rows of acrostichal hairs. . . . . . . . . . . 6r. 
Mesonotal hairs dense, the acrostichal area covered with 
irregular hairs; ovipositor tipped with pollen; veins ! 
blácketi-4 4-7 9v 2.7. v8.0.4 9 4 coo oo PENNE 
Var. HYJENOIDES, nov. var. (1). 
61. Ovipositor tipped with pollen; mesonotum without lateral 
hairs; wings nearly three times as long as broad, veins 
yellowish; last sternite of c abdomen with a fringe of 
yellwtiisüées. 4.5. 20. 2 2 ooh cU CPS P BNUE 
var. JUVENIS, S. Str. (2). 
Ovipositor completely shining; mesonotum with sparse lateral 
hairs; wings broader, veins brown; abdomen not fringed. P. juvENis, 
: var. PUERINUS, nov. var. (3). 
62. Disk of thorax uniformly shining; front tibie incrassate. . . . . . . . . . . . . 63. 
Thorax with two shining vitt:e more or less connected with 
a supra-alar shining spot; tibiz& not swollen (P. viífatus, 
nov.$D) . .52 2.7. 08 3 7. vacui eu dU RE M E IE M M TM 
not ciliate, middle femora not setose, biseriately black-setulose as usual with seventeen setule to each row, middle 
tibi: two-thirds as long as their femora, the apical spur minute"  Halteres tipped with a small black spot. 
Veins thin and brown, the second, third and fourth sections of the costa proportioned 3 : 2.5 : 1, third vein 
recurved, ending slightly beyond the tip of the wing, fourth vein more nearly straight, crossveins at two-fifths the 
heap meeting, the posterior slightly oblique, twice as long as the anterior, sections of the fifth vein proportioned 
: 06,6 : 1, anal crossvein at an angle of fiíty-five degrees, anal vein weak, vanishing at its base; marginal cilia. 
diae than the anterior crossvein. 
One specimen, Tacoma, Washington, August 27, 1911. ; 
(1) Platypalpus juvenis, var. hysenoldes, nov. var. — A female from Vashon, Washington, May 28, 1917. - 
differs from the following varieties in having the mesonotal hairs more abundant, thus resembling the species 
P. glacíalis, the hairs between the dorsocentral glabrous stripes irregularly placed. Third antennal joint equal to the — 
arista; vertical bristles blackish; end of ovipositor opaque; wings three times as long as broad, veins blackish, stigmal 
thickening pronounced, 
(2) Platypalpus juvenis, var. juvenis, s. str. — Length 2 mm. Black, disk of the mesothorax shining and 
nearly bare of hairs, legs yellow, tibial spur minute, tarsi not annulate, antennz black, the last joint conical and 
subequal to the arista, front and face densely cinereous, crossveins meeting. Occiput densely cinereous pollinose, 
sides of the rather broad front diverging above; palpi broadly oval of moderate size, yellow, silky in front and with 
a single white apical seta; antennsz two-jointed, the basal joint sometimes brown, the outer joint two times as long 
as wide and slightly shorter than the arista; two pairs of relatively strong yellow vertical bristles and one pair of 
ocellars. Humeri, sides and hind margin of the mesonotum and pleurz except a large sternopleural spot, cinereous 
pruinose, one pair each of the usual bristles yellow, two rows of acrostichal hairs, dorsocentral stripes bare, sides of 
notum with a few fine white hairs; abdomen shining black, last sternite C with a dense friuge of yellow setz, 
Pygidium large, its dorsal valve produced backwards as a rather slender curved, nearly smooth process which bears 
a yellow fringe on its right side, apex of the ovipositor pollinose, Base of the posterior coxa a little darkened, cilia 
of the front femora very short and sparse, middle femora with fourteen black setz in the postero-flexor row and 
without additional yellow setz, middle tibiz five-sixths as long as their femora. Wings nearly three times as long as 
wide, veins yellowish, costa not thickened, its second, third and fourth sections proportioned 4 : 2.5 : r, third and 
fourth veins parallel, the third vein ending at the tip of the wing, posterior crossvein nearly transverse, twice as long 
as the anterior, located at three-sevenths of the wing-length, sections of the fifth vein proportioned 0.4 : 0.6 : r, anal 
crossvein forming an angle of sixty degrees, anal vein almost wanting, marginal cilia short. 
Nine specimens, Kokanee Mountains, 7000 feet, British Columbia, collected by R. P. Currie for the U. S. 
National Museum; Dubois, Wyoming. September, collected by W. M. Wheeler; and Mount Rainier, Washington 
(Melander). A specitien from San Diego, California (E. P. Van Duzee) has the pygidium more globular. 
(3) Platypalpus juvenis, var. puerinus, nov. var. — A series of specimens from the Kokanee Mountains in 
British .Columbia and also from Mount Katahdin, Maine, differs as follows : the third antennal joint is usually 
slightly longer than the arísta, the vertical bristles are brown, the end of the abdomen c lacks the conspicuous fringe, 
the dorsal pygidial valve is more blunt, more or less rugulose and not elaborately fringed, the ovipositor is completely 
shining, the sides of the mesonotum almost devoid of hairs and the wings are broader, with stronger, brownish veins 
and with the end of the first vein thickened. 
