222 



Knob of halteres black, the stalk yellow. Wings clear, veins 

 brown. 

 Eyes distinctly but not very widely separated ; second antennal 

 joint very large, globose ; antennal hairs pale ; length of 

 antenna distinctly exceeding that of the head and thorax 

 together; proboscis over half as high as head, acute and 

 highly chitinous. Mesonotum covered with very short, soft, 

 closely placed hairs, which have a small pit at the base of 

 each; disc of scutelluni similarly haired, the margin with 

 short bristles. Abdomen elongate, narrow at base, becoming 

 much broader before middle, narrowing a little at apex. Legs 

 slender, hind femora slightly bent; fore femora slightly 

 thickened, the antero-ventral surface sometimes with as 

 many as ten short black thorns, which are arranged distally 

 in two rather irregular rows extending from the middle to 

 the apex of the femur ; mid femora with 3-4 thorns on the 

 apical third of the antero-ventral surface; hind femora with 

 3-4 rather long slender thorns on the same surface, which 

 are difficult to see owing to the presence of the distinct 

 surface hairs on that part ; basal joint of hind tarsus slightly 

 longer than the remaining joints together; claws on all tarsi 

 subequal and rather long. Venation of wing as already 

 indicated, fourth vein forking at cross vein, the base of the 

 lower branch very weak; costa slightly hairy. Length, 



3.5-4.5 mm tibialis Meigen. 



This common European species has been recorded from New 



Jersey by Smith. It is represented in the collection here by 



four females from Algonquin, 111. (Nason), and one female 



from Anna, 111. (F. S. Earle). 



Mesonotum black, somewhat polished, but granulose ; apices of hind 



tibias black; the length of the last section of third vein distinctly 



exceeding the length of the section of the media bordering the 



lower side of the closed cell ; third vein reaching about nine tenths 



of the distance to the wing-tip. 



Female. — This species differs from tihialis only as follows: 

 The apices of fore and mid femora, the bases and apices of 

 the tibiae of the same legs, and the apical third of hind femur 

 and apex of the hind tibia are narrowly black; the tarsi 

 have the apices of the first three joints narrowly and the 

 last two joints entirely blackened. The legs are very similar 

 in shape and armature to those of tihialis, but the thorns on 

 the hind femora are more distinct. The wing venation differs 



as indicated. Length, 4.5-5 mm snhasper Coquillett. 



Male. — This sex is represented in the collection here by a single 

 example taken at the same time as the female from St. 

 Joseph. Though this specimen differs very considerably from 

 the female in color and size I can not consider it as distinct 



