54 Psyche [April 



except the posterior pair white; a single pair of scutellars; two humerals, two 

 notopleurals (both large), one posthumeral; propleura with two clusters of long 

 pale hairs, above and below, among the latter some have a rather dark appearance 

 in certain lights, but there is no black bristle; on the upper part of the sternopleura 

 is a cluster of long, loose, woolly, white hairs, very conspicuous; metapleura 

 bare; squama pale yellow with white hairs; halteres yellow, a little brownish at 

 the root. Front coxae white pollinose and covered in front with long, erect and 

 dense white hairs, no black spines or bristles at tip; front femora thick, not taper- 

 ing for more than half their length, then with a deep, oblique excavation below 

 cutting out more than half the thickness of the member, beyond which the under 

 side is widened again in a thin longitudinal plate to the tip; the sloping proximal 

 surface of the excavation bears a diagonal series of short black spines; the femirr 

 has rather conspicuous white hair on its outer side and on the inner side before the 

 excavation are several much longer white hairs; front tibiae strongly bowed out 

 where they oppose the excision of the femur and bare on the flat opposing surface 

 except for a row of minute black spines on the edge which continue, though very 

 small, to the tip ; on the underside of the femur near the base are a few short spines 

 in a row; middle coxa with long, erect white hairs on outer part of the front side; 

 middle and hind femora long, slender and somewhat bowed; hind trochanter below 

 with a bunch of Ixlack spines which unite to form a tapering, sharp, thornlike 

 process, very striking; middle tibia and tarsus shortened, not much longer than 

 the femur, last tarsal joint flattened and enlarged, black. Wings rather wide with 

 veins yellow at base to a variable extent, unspotted, evenly and moderately infus- 

 cated in color; first posterior cell narrowed at end, not much more than half as wide 

 as the length of the posterior crossvein; alula with a row of long, white hairs. 

 Abdomen coppery above, more or less obscured with white pruinosity; all the hairs 

 of the abdomen are whitish and of imusual length, those on the sides near base quite 

 woolly and very striking; fourth sternite projecting V-shaped; hypopygium 

 moderately prominent but not uniformly so. Length, 4.8 mm; of wing, .5. mm. 



Female. Color of face from pale yellowish to brownish; front femur gently ta- 

 pering, not notched, below with an irregular double row of small spines; front tibia 

 with a row of minute spines on inner side which does not extend to the tip. Length, 

 5.3 mm; of wing, 5.2 mm. 



Seven males and two females: Lawrence, Kans., June, 1893; 

 Brookings, S. D.; and Green River, Wyo., Sept. 1, 1896. I 

 remember collecting the specimens at the edge of the river at 

 Lawrence, and I at once noticed the peculiar front legs of the 

 male. The Green River specimens were taken on an occasion 

 when I had to wait between trains all day at the town, but I 

 do not remember the species. My description does not sufficiently 

 bring out the characteristic pale yellowish soft dull coloring of 

 the whole fly, which suggested the specific name. Only the 

 coppery dorsum and greenish abdomen are moderately bright. 

 The type locality was forty miles north of Lusk, Wyoming. 



