512 PROCEEDINGS OF THE ACADEMY OF [Oct., 
10. Pleura unstriped; Sc rather short, extending to about one-fourth 
the length of the sector; no dark blotch at the tip of Sci; 
apices of cells R3 and Rs largely darkened. (Eastern United 
States.) hlanda Osten Sacken. 
Pleura striped with brown; Sc long, ending at about half the 
length of the sector; a dark blotch at the tip of Sci] apices of 
cells Rz and Ri only slightly darkened. (Western United 
States.) - cali/ornica Alexander. 
11. Antennae orange at the base, the flagellum dark 12 
Antennae black throughout 15 
12. Cell 1st Mi closed; femora with a dark brown subterminal 
annulus. (Eastern United States.) sulphurella Osten Sacken. 
Cell 1st M2 open; femora without a darker subterminal annulus„.13 
13. &c short ending before the origin of Rs, this distance being about 
equal to the vein R2. (Western United States.) 
flavihasis Alexander. 
Sc longer, ending opposite, or just before, the origin of Rs 14 
14. Male hypopygium with the dorsal angle of the pleurite stout, 
with numerous (about fifteen) slender hairs; ventral append- 
age simple, stout, tipped by a blunt black spine; second 
appendage a powerful, curved, subchitinized arm directed 
proximad. (Northeastern United States.) florens Alexander. 
Male hypopygium with the dorsal angle of the pleurite slender, 
with a few (about ten) stout hairs; ventral appendage bifid, 
the arm with a long slender black spine; second appendage a 
slender pale arm that is almost straight, with two hairs at 
the tip. (Eastern United States.) cognatella Osten Sacken. 
15. Wings with slender veins, clouded with a milky suffusion; Rs 
very long and straight. (Northwestern North America.) 
galactoptera Bergroth. 
Wings with stouter veins, pale gray to hyaline; Rs shorter, more 
arcuated basally •■ 16 
16. Subcosta short, ending before the origin of Rs, the distance about 
equal to the r-w cross-vein; vein Ro oblique, a little longer 
than the cross-vein r-m; male hypopygium with the gona- 
pophyses and penis-guard fused into a large, prominent, 
cylindrical tube. (Northeastern United States.) 
novehoracensis Alexander. 
Subcosta longer, ending about opposite the origin of Rs; vein R-i 
longer, the cell R2 being larger; male hypopygium with the 
gonapophyses and penis-guard not fused into a cylindrical 
tube _ ...17 
17. Wings long and slender with a strong grayish brown suffusion; 
halteres elongated; male hypopygium with the ventral pleural 
appendage very elongate, slender, slightly expanded toward the 
tip. (Eastern Rocky Mountain region.) filicauda Alexander. 
Wings broader, not strongly tinged with grayish ; halteres shorter 
male hypopygium with the ventral pleural appendage not 
strikingly elongated 18 
