MAY FLIES AND MIDGES OF NEW YORK 173 



that tlie larvae are found only in well aerated water. When taken 

 from the streams and placed in still water they soon die, usually 

 within a few hours. (P1.36, fig.11-25, after Heeger; 1S53 ; and 

 pl.20, fig.9). 



Pupa. The pui)ae are apparently Avithout thoracic breathing 

 organs; if they are present they must be extremely minute and 

 have been overlooked. The anal end with G or 8 short setae; the 

 posterior margin of each abdominal segment with sjiines or setae. 

 (See pl.48, fig.13, in Bul.GS, N. Y. State Museum, '03.) 



Imago. Head small; broad and flattened in front, the face pro- 

 longed into a short broad proboscis; e3'es elongate, only a little 

 emarginate, ocelli wanting. Antennae inserted close to the e3'e 

 margin, 14-jointed in the male, basal joint broad and disk-like, 

 the fourteenth very much elongated like that of the males in 

 Chironomus and of a similar structure; densely plumose; 

 antennae of the female seven or eight jointed (pl.31, iig.T), the 

 joints rounded or oval, the last one somewhat longer and cylin- 

 drical. In both sexes the basal joint disk-like. Palpi four- 

 jointed. Thorax highly arched; prodmed more or less over the 

 head, slightly flattened in front of the stutellum. Abdomen like 

 that of most C h i r o n o m i d s ; rather long and slender in the 

 male; shorter and stouter in the female. Legs long and rather 

 stouter than in Chironomus, fore metatarsus equal to or 

 shorter than the tibia; the fourth tarsal joint, of most species at 

 least, short, obcordate. Wings bare, venation as shown on pl.30, 

 fig.] 3, resembling T a n y p u s in having the M-Cu crossvein ; the 

 subcosta slender, but distinct, R^ and H^^. ending in the costa; 

 betAveen these is the slender and delicate Ko-fjl the media is 

 simple; the R-M crossvein oblique; the M-Cu crossvein erect; the 

 cell M is present; the cubitus forks a little before the M-Cu 

 crossvein; the humeral crossvein is present. Genitalia as shown 

 on pl.32, figs. 5 and 14. 



Several species have been recorded from Europe and North 

 America. Haliday in Walker's Ins. Brit. Ill (1856) has recorded 

 species the males of which are said to have bare or short-haired 

 antennae. 



