AMERICAN DIPTERA. 325 



outer third before the tip, on tlie underside with a short, thick, transverse bifur- 

 cate process, the outer projection of which is closely fimbriate within with black 

 scale-like hairs, while the inner is sharply angulate and terminates in a distal 

 direction as a short spur, midway between the outer projection and the tip of the 

 femur are three closely placed bristles; articulating into the distal end of the 

 femur is a large bristling projection on the tibia, distal to which and articulating 

 with the fimbriate edge of the outer bifurcation of the femoral process is a small 

 median tubercle, across from this on the inner (posterior) side of the tibia is a 

 prominent bifurcate bristly process diiected distally and medially, beyond which 

 is another median tubercle, but larger and more pointed than the first, or some- 

 times reduced to a mere swelling; the tips of the two bifurcate processes are 

 always black, the bases are always concolorous with the rest of the legs ; middle 

 tibiae of both sexes tipped witli a series of from five to eight stifi" black bristles 

 on the inner side. Wings sometimes faintly smoky, veins narrow to strong ; stig- 

 mal spot very faint; furcation of the third vein opposite or in advance of the tip 

 of the marginal cell, its posterior branch ending beyond the wing-tip; the first 

 section of the anterior boundary of the discal cell about one-fouith the length 

 of the second section ; hind margin of the discal cell shorter than the outvfard 

 continuation of that vein. 



Colorado and Idaho (J. M. Aldrich). Ninety specimens of both 

 sexes. 



Empis «loIabi'aria sp. nov. 

 Male and Female. Length 6 mm. — A brownish species. First antennal joint 

 one and one-half tijnes the second; palpi yellow; occipital bristles numerous, 

 confused, long below. Scutellum with six marginal bristles, the cluster in front 

 of the halteres consisting of six to eight, a small bunch of hairs present above 

 the base of the front coxse ; mesonotal vittai broad, brownish, abdomen of the 

 male brownish gray, concolorous with the scutellum, intervittal spaces and the 

 pleurae; abdomen of the female gray. Abdomen short; hypopygium small, outer 

 portion of the base of the central filament visible, the middle lamellae small, the 

 upper lamellae porrect, extending upwards. Coxae blackish, the very tips paler, 

 trochanters black; legs short, reddish, the tarsi black, hind femora and tibiae 

 somewhat bent, rather stout, the hind femora not reaching the end of the abdo- 

 men, tarsi long spinose beneath, hairs of the tibiae strong, bristles short ; male 

 hind femora slightly swollen on the posterior side before the tip, beneatli with a 

 subapical transverse bifurcate process, the outer projection of which is long and 

 tipped with a minute pencil, male hind tibiae suddenly enlarged beyond the knee 

 and there sparsely ciliate on both sides with black bristles, beyond the swelling 

 there is a prominent process on the outer inferior edge fringed on the proximal 

 side with short scale-like bristles. This articulates with the larger projection of 

 the femoral process. Wings rather broad in the male, slender in the female, 

 clear hyaline, the third vein furcate beyond the tip of the marginal cell, the pos- 

 terior branch ending at the wing-tip, the proximal section of the anterior bound- 

 ary of the discal cell more than one-fourth as long as the distal section, the hind 

 boundary three-fifths as long as the continuation of that vein. 



A male and a female ; California (Baron). 



TEANS. AM. ENT. SOC, XXVIII. SEPTEMBER, 1902. 



