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thirds as long as the height of head. Mesonotiim with 

 scattered hairs on the disc. Abdomen flattened, broadened 

 just before the middle, the apical half parallel-sided, 

 rounded at apex, segments with short surface hairs. Legs 

 with the surfaces very slightly hairy, the hind femur very 

 much swollen on the apical half, and slightly bent, the con- 

 cavity on the posterior side; from before the middle to the 

 apex on both the antero-ventral and postero-ventral surfaces 

 there are distinct, closely placed uniserial thorns; fore and 

 mid femora unthickened and without distinct thorns; hind 

 tibia bent, fitting into the space between the rows of thorns 

 on the femur, and about four fifths as long as the femur; 

 basal joint of hind tarsus subequal in length to the next three 

 taken together; fourth joint about half as long as fifth; all 

 tarsal claws subequal in length. Third vein three fourths 

 of the wing-length ; costa slightly hairy ; fourth vein forking 

 at cross vein. Length 2.5 mm crnssifemorata, n. sp. 



Locality, ]\It. Carmel, 111., May 28, 1884 (H. Garman). Two 

 females. 



This species and femorata belong to the genus Serromyia. 

 7. Knob of halteres black; mesonotum opaque gray, with distinct, 

 central, brown vitta. 



Female. — Black-brown, opaque, the back of head, mesonotum, 

 pleurjB, coxai, and abdomen with thick gray pollinosity, 

 giving to the insect a pale grayish appearance. Face brown, 

 shining, with faint whitish pollinosity; antennae brownish 

 yellow, paler on the basal half ; palpi yellowish. Mesonotum 

 with a bifid brownish central vitta, and a subdorsal streak 

 of same color on each side which does not extend much 

 beyond middle anteriorly; when viewed from some angles 

 there is a distinct post-humeral blackish spot which is sur- 

 rounded by very distinct whitish pollinosity, this condition 

 being reversed when the position is reversed ; humeral region 

 yellowish ; scutcllum colored like disc of mesonotum. Legs 

 yellow, coxffi blackened, trochanters brown ; apices of mid 

 femora and bases of mid tibiae slightly browned ; apices of 

 hind femora and bases of hind tilnee distinctly and broadly 

 browned ; apices of all tibiae and of the first three tarsal 

 joints, as well as the whole of the last two tarsal joints, 

 brown. Wings clear, veins very pale. Halteres yellow, 

 knobs brown-black. 



Eyes narrowly separated ; antenna? with the apical five joints 

 distinctly elongated, the entire length of antenna equal to 

 about one and one third times the length of the head and 

 thorax together; proboscis about half as long as height of 

 head. Mesonotum with very numerous short, closely placed 



