328 A. L. MELANDER. 



each side of the well-marked median glabrous streak) ; none of the metatarsi en- 

 larged, the hind tarsi stoutest; hind femora distinctly bowed, hind tibife some- 

 what bent; hind femora of the male beneath with a single preapical flat tuber- 

 cle which is tipped at its outer corner with a short pencil of black hairs, between 

 this projection and the tip of the femur is a black fringe on each side beneath, 

 the outer one containing only three minute hairs closely placed, the inner one 

 conspicuous, consisting of four long, stout bristles, and as many hairs; the hind 

 tibiae of the male stout, with two prominent basal tubercles, one on each side of 

 the median line and one in advance of the other, the more basal (on the inner 

 side) capped by a pencil of black hairs, the other with a dense short brush. 

 Wings clear hyaline, the third vein furcate just beyond the end of the marginal 

 cell, its posterior branch ending at the extreme wing-tip or slightly in advance; 

 the first section of the front border of the discal cell one-third to one-fourth the 

 length of the outward continuation of that vein ; the third vein turns slightly 

 upward, leaving the first posterior cell distinctly wider than the first submarginal. 

 5 mm. 



Numerous specimens from Idaho, collected by Prof. J. M. Aldrich. 



Eiupis seripes sp. nov. (Fig. 141). 



Female. Length 7.5 mm. — Stout species covered with whitish gray pollen. 

 Antennae stout, first joint two times the second ; palpi strongly infuscated, except 

 the apex, provided with numerous minute hairs below ; occipital bristles strong 

 and deuse ; pronotal, pectnl, humeral and coxal bristles prominent; scutellum 

 with eight to ten bristles, four to six short and four long, alternating, the central 

 pair long; in front of the halteres is a cluster of about nine bristles. Thoracic 

 vittae narrow, faint, not at all brownish, but nearly concolorous with the rest of 

 the body. Legs stout, dark fuscous, femora above, hind tibiae apically and tarsi 

 blackish; hind femora and tibiae bent, the tibial bristles stout. Wings nearly 

 clear, the veiy faiut stigmal spot extremely narrow, veins blackish, clear-cut, 

 the third vein sinuous, furcate beyond the tip of the marginal cell, the posterior 

 branch terminating before the wing-tip, the first section of the front margin of 

 the discal cell one-fourth the length of the second section, the posterior border 

 two-thirds the length of the vein between the third and the fourth posterior cells. 



Male. — Differing from the female very markedly in the color of the pollinose 

 coating which is not pure gray but mixed with brown. The vittae are brown 

 and diffuse into the intervittal spaces. The armament of the legs is very similar 

 to that of mixopolia. but is carried to a greater extent ; the apical fringe of the 

 lower inner side of the hind femora contains about ten strong bristles besides 

 the four hairs; the more distal tubercle of the tibia is longer. 



This, together with the preceding species, differs from all the 

 other species of Empis in the structure of the armament of the 

 male hind knees. It is distinct, however, from mixopolia, being a 

 much larger and more robust form. The black color of the whole 

 coxa, the numerous scutellar and other bristles, the larger discal 

 cell and diffused vittse of the thorax, the lateral ones of which 

 are not so much abbreviated as in mixopolia, and the specialized 



