FAM. EMPIDID/E * 4:833 
63. Tarsi black; bristles, coxe' and veins blackish; tibial spur 
moderate and stout; mesonotum pollinose on sides and 
Duro uc ME HM LUI LU ERU CIEL avs VERPUS, HOV- SD« (Ik 
'Tarsi strongly annulate; bristles, coxe& and veins yellow; 
clsbiubuesasbGs C000 Loconure con eMe MEC e e Le Ira A C MN UTD ERNEUT cro. 
64. Mesonotum mostly shining, not pollinose in front of the 
scutellum; last section of the fifth vein distinct (P. politus, 
Hor Dc n Hou Ee MI UEU rau uoa Dg m M c5. 
Center of the mesonotum shining ; outer angle of the second 
basal cell rounded, last section of the fifth vein obsolete; 
baseoftheantenneyelow -.-..-... . . .-. .,. P. ENERVATUS, nov. sp. (a). 
65. Fourth vein very perceptibly sinuous; base of the antennae 
VBlOME Du v Uc cta adici eat. o P, POLDITUS, OV. Sp. (3) 
(1) Platypalpus verpus, nov. sp. — Male. Length 2 mm. Black, disk of mesonotum polished, legs 
brownish yellow, front tibiae swollen, veins, bristles and antenna black, crossveins separated. Occipital hairs silky 
and white, two vertical bristles erect, blackish; face with parallel sides, white, front narrow, gray pollinose; ground 
color of the palpi piceous. the setze whitish, proboscis black; third antennal joint pyriform, two-thirds as long as the 
arista. Humeri, notopleural sutures, rear of mesonotum and scutellum gray pollinose; acrostichal and dorsocentral 
rows and lateral patches of setula present; one humeral, three prealar, one posterior dorsocentral and the central 
scutellar bristles evident; pollen of the pleure silvery gray and dense, about two-thirds of the sternopleurz bare. 
Abdomen shining, its hairs sparse and dusky, pygidium large and obliquely ascending and rounded, fringe of the left 
dorsal valve long and dark. Base ofthe coxa blackish, front femora stout, with twelve pale flexor setze, middle femora 
with about eighteen short black setulae in each flexor row, middle tibie five-sixths as long as their femora, the terminal 
spur rather short, stout and black, hind knees infuscated. Halteres with white knobs; calypteres dusky. "Wings three 
times as long as wide, anal angle rather pronounced, veins strong and blackish, costal sections proportioned nearly 
4:3:2: 1, third vein nearly straight, fourth vein curving and parallel with the third on the outer half, posterior 
crossvein rather oblique, sections of the fifth vein, 2 : 3 : 2.5, base and apex of anal vein lacking. 
Holotype, Union Flat, near Pullman, Washington, June 3, 1918 (Melander). 
(2) Platypalpus enervatus, nov. sp. — Male. Length 2 mm. Black, sides and back of the mesonotum 
densely cinereous pollinose, the center of the disk polished, bristles yellow. | Head cinereous, face and front 
rather narrow, their sides parallel, epistome shining; antennz two-jointed, the basal joint yellowish, the outer 
joint black, ovate, nearly twice as long as wide and three-fourths as long as the arista; palpi oval, with white 
sete, proboscis black. Thorax nearly bare, but with a group of sete about the notopleural bristle; pleurz 
densely whitish pruinose, the sternopleural spot of moderate size; abdomen polished, pygidium more or less 
triangular in outline and rather small. Legs including the coxe light yellow, the tarsi strongly annulate, front 
femora as thick as the middle ones, with twelve stiff pale cilia beneath, front tibia swollen, middle femora with 
a posterior row of twelve pale sete, the middle tibie nearly as long as their femora and with a strong 
black-tipped spur.  Veins pale, third vein ending at the wing-tip, straight, subparallel with the fourth, second, 
third and fourth sections of the costa proportioned 3.2 : 2.3 : 1, the costa slightly thickened beyond the first vein, 
posterior crossvein rather oblique, slightly before the middle of the wing, much beyond the anterior crossvein, 
rounding into the fifth vein, the last section of which, together with the anal crossvein and the anal vein, obsolete, 
marginal cilia very short. 
One specimen, San Diego, California, May, collected by E. P. Van Duzee. 
(3. Pliatypalpus politus, nov. sp. — Male. Length 2.6 mm. Robust, black, dorsum shining, legs 
light yellow, femora ciliate, tibial spur strong, tarsi annulate, antennae largely yellow, posterior crossvein at the 
middle of the wing.  Occiput finely cinereous dusted, íront rather narrow, its sides parallel, densely  whitish 
pruinose, face white, epistome shining; palpi golden yellow, elongate oval, with whitish sete and long apical 
bristle, proboscis short, black; antenna two-jointed, the outer joint short-ovate, its tip black, the arista twice as 
long as the outer joint; vertical bristles yellow and short, one pair of ocellar and one of vertical bristles — Humeri, 
notopleural sutures and pleure densely whitish pruinose, the glabrous spot of the sternopleurze moderate in size, 
scutellum and metanotum subshining; the usual bristles yellow, setulee very sparse and fine; abdomen shining, 
pygidium small Legs robust, front tibiae inflated, larger than the others, middle tibia nearly as long as their 
femora.  Veins brown, costa a little thickened between the first and second veins, its second, third and fourth 
sections proportioned 4.5 : 2.4 : r, third vein straight, fourth vein with a perceptible backward curvature and then 
turning forward and parallel with the third at the tip, the first posterior cell widest at its middle and ending at 
the apex of the wing, posterior crossvein nearly tranverse, one-third longer than the anterior, the distance between 
