326 DIPTERA 
Arista much shorter than the elongate third antennal joint; 
front and face broad ; hind femora blackish apically, middle 
femora with fine yellow cilia; third and fourth veins 
pariieléo- 2. 0 So 08S 0 NEU EDAM E 
39. Anal cell completely lacking; antenna black, the third joint 
broadly oval and one-half the arista; palpi yellow; front 
P. rrAMMIFER, Melander. 
shining; tarsi dusky distally, not annulate. . . . . . P.cuwErENNis, Melander. 
Analcrossvein and part of anal vein evident, as usual. . . . . . . . . - . . . «. 40. 
40. The elongate third antennal joint and arista pubescent; wings 
marked with blackish spot over crossveins. . . . . . P.PicrIPENNIS, Bezzi. 
Arista bare; wings notspotted . . . . . . . . & . 0E. 
41. Base of the antennz yellow ; sides of front parallel or nearly 
s0; come andlegs yellow. 5... 0 EXICNNS c PRU 
Antennz completely black : if the base of the antenne is 
brownish the sides of the front diverge above and the face 
isbroad . . . . . «.. S. WX wA Ic 
42. Front opaque, pleurz mostly pollinose; tarsi weaklyannulate. . . . . . . . . . - A OAK 
Front and greater part of the pleure shining ; only the last d 
jointofthetarsi dark. . . . . . : " d iE 
43. Face much narrower than the front; proboscis yellowish; last 
two segments of the Q abdomen ochraceous; femora 
scarcely thickened, no tibial spur; hairs of the notum long ; 
third antennal joint long, hairy and equal to the rather 
sldterba . .0. s... S 2o 40S P AMEN 
Face much narrower than front; only last tarsal joint 
blackened ; proboscis brown; abdominal segments shining 
except on incisures; legs rather slender, no tibial spur; 
notal hairs sparse and moderate; third antennal joint 
hairy and equal to the rather stout arista; pygidium robust, 
forming about one-third the abdomen . . . . . . . P. TENUIS, nov. sp. (1). 
on each side of the usual two rows of black setulz, those behind eight in number and longer than the diameter of 
the femur, middle tibiz two-thirds as long as their femora, Wings lightly infumated, veins brown, costa not at 
all thickened, its second, third and fourth sections proportioned 4.2:2.2: 1, pedicel of the second and third vein 
arising near the base of the second basal cell, third vein ending beyond the apex of the wing, convergent with 
the fourth, the first posterior cell widest at three-fifths its length, crossveins near the basal third the 
posterior arising slightly before the short anterior cros vein, sections of the fifth vein proportioned 0.4: 0.5: 1, anal 
crossveia at an angle of thirty degrees, evanescent at its tip, anal vein very weak, vanishing at its base. 
Type, Chicago, Illinois, August 1o, 1901 (Melander). Another specimen from Niagara Falls, New York, submitted 
by M. C. Van Duzee, has the arista wholly white and the third vein a little less recurved. 
(1) Platypalpus tenuis, nov. sp. — Male. Length 2.2 mm. Black, legs entirely pale yellow except the 
black outer two-thirds of the last tarsal joint, base of antennz yellow, veins and bristles whitish, disk of mesonotum, 
polished, front and pleurz pollinose, crossveins approximate and transverse, Hairs of the occiput long sparse and 
white; face narrower than the front, gray; epistome shining; proboscis brown, palpi small and yellow; third 
antennal joint brown, pubescent, triangular, over twice as long as wide and slightly longer than the closely 
pubescent black arista. Humeri, scutellum, narrow sides of the mesonotum and pleurz except sternopleura whitish 
gray pollinose, the usual bristles pale yellow, acrostichal and dorsocentral hairs individually distinct, together 
forming four rows, the interspaces glabrous, lateral hairs very sparse. Abdomen entirely shining black, nearly bare, 
last sternite with a conspicuous fringe of pale yellow hairs, pygidium forming a large rounded termination to the 
abdomen, its valves not fringed. Legs rather slender, front femora not ciliate, middle femora with about twenty 
fine blackish setula in the anterior row and about twelve fine yellowish setz in the posterior row, no other bristles, 
