372 



Abdomen with hairs of moderate length on the entire surface ; hypo- 

 pygium similar to that of Tanypus dyari (PI. XXVII, Fig. 12), ex- 

 cept that it is stouter, the apical portion tapering more abruptly, and 

 the black thornlike apical process of that portion being about a fifth 

 the length of the pale part. Legs slender, fore tarsus long-haired, 

 basal joint about three fourths as long as fore tibia; mid and hind legs 

 and apices of fore tibiae with long hairs. Distance from humeral vein 

 to cross vein less than half the distance from cross vein to wing-tip ; 

 third vein not extending to curve of wing. 



Female. — Slightly paler than the male; the antennae entirely yel- 

 low ; thorax almost the same as in the male ; abdomen brownish, the 

 posterior margins yellowish ; legs and wings as in the male. 



Antennae about equal in length to thorax, basal joint less swollen 

 than in the male, apical joint elongated, hairs rather long but sparse. 

 Thorax as in the male. Abdomen stout ; surface hairs moderately 

 long. Legs less distinctly hairy than in the male, especially the fore 

 tarsi ; basal joint of fore tarsus over two thirds as long as fore tibia. 

 Distance from cross vein to apex of wing two and a half times as 

 great as distance from cross vein to humeral vein. 



Length: male, 3-3.5 mm.; female, 2.5-3 mm. 



Type locality, Easton, 111., May i, 1914. Several specimens of 

 both sexes taken at the Central Ditch, over one mile from Easton. 

 Early stages unknown. 



5. Tanypus piloselIvUS Loew 



Tanypus pilosellus Loew, Bed. Ent. Zeitschr., 1866, p. 5. 



Male. — Yellowish to grayish. Head, antennae, antennal plumes, 

 and palpi yellow; basal joint of antennae brown. Thorax generally 

 grayish, or brownish yellow with gray pollinosity, stripes sometimes 

 indistinct ; scutellum yellow, generally brownish at center ; postnotum 

 dark brown. Abdomen gray or blackish, apices of all except the last 

 segment yellowish white, the second, fourth, and sixth most conspicu- 

 ously so; apical portion of lateral arm of hypopygium whitish. Legs 

 yellow or whitish, apices of mid and hind tibiae with a short black 

 comb. Wings clear, veins yellow. Halteres yellow, knob brownish. 



Antenna much shorter than wing from cross vein to apex ; the last 

 joint not one and a half times as long as the preceding flagellar joints 

 together. Hairs on mesonotum very long, regularly arranged along 

 the whole length of the spaces between the vittae ; no conspicuous 

 group in front of wing-base, and no discernible sternopleural hairs ; 

 scutellar hairs verv long and numerous. Abdomen slender, the sur- 



