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, nsually 

 within a few hours. (P1.36, fig.14-25, after Heeger; 1858; and 

 pl.20, fig.9). 



Pupa. The i)npae are ap]»arently without 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 spines or setae. 

 (See pl.l8, fig.13, in Bul.G8. X. Y. State Museum, '03.) 



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

 longed into a. short broad proboscis; eyes elongate, only a little 

 emarginate, ocelli wanting. Antennae inserted close to the eye 

 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 jdumose; 

 antennae of the female seven or eight jointed (pi. 31, tig.7), 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; ])rodu(ed more or less over the 

 head, slightly tlattened in front of the scutellum. Abdomen like 

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

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

 stouter than in (' h i r o n o m u s , fore metatarsus ecjual 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 Tan y pus in having the M-Cu crossvein ; the 

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

 between these is the slender and delicate R2+,. ; 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, III (1856) has recorded 

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

 antennae. 



