1923 ] New Species of North American Dolichopodidce 
65 
first joint as long as the three following taken together, third 
and fifth of nearly equal length second slightly longer and 
fourth shorter than third. Hind tarsi brown, first and second 
joints of equal length, the following joints of slightly decreasing 
length. Calypters, their cilia and the halteres brown. 
Wings tinged with brownish; third and fourth veins par- 
allel beyond the cross-vein, widely separated; last section of 
fourth vein with a faint brown spot at its basal fourth; last 
section of fifth being twice as long as the cross-vein; anal angle 
prominent. 
A female which probably belongs with this species differs 
in the thorax having purple reflections; legs plain and a little 
more yellow; middle and hind basitarsi yellow with a black 
tip; calypters and knobs of halteres more yellowish, the former 
with black cilia; middle tibise with two bristles below and several 
on upper surface, wings with the spot at basal fourth of the 
last section of fourth vein very conspicuous. 
Described from one pair taken in Maine; the holotype, 
male, was taken at Machias, July 20, 1909, and the allotype a 
female at Bar Harbor, August 4, 1918; both were taken by C. 
W. Johnson. He sent them to me with the name wheeleri attached 
but had never described them. 
This is very much like oedipus Wheeler, but this form has 
the legs more yellowish; the middle tibise of the male of a little 
different shape; the middle basitarsus contracted in the 
middle, more enlarged apically, and not ending in a point; 
their third and fourth joints are also nearly twice as long as in 
oedipus ] the brown spot on the fourth vein of the wing is very 
indistinct in this form. The females of the two species are 
probably difficult to separate. 
Hercostmus costalis sp. nov. 
Male; Length 3 mm.; of wing the same. Face of mod- 
erate width, silvery white. Front thickly covered with white 
pollen, so as to conceal the ground color when viewed obliquely. 
