MAY FLIES AND MIDGES OF NEW YORK 93 



kk Media present ................ (X ylocr y pt a 1 ) 



I Femora unarmed ......... 8. Ceratolophus 



II Some of all the femora spinose beneath 



9. Palpomyia 



m Neither fore nor hind femora thickened 2 

 n Having hairy soles (plantae) 



1. Subgenus A 1 a s i o n 



nn Having spinose soles (plantae), pl.17, fig.16 

 2. Subgenus Sphaeromyas 

 mm Either fore or hind femora thickened 



n Hind femora thickened, spinose beneath 



3. Subgenus Serromyia 

 nn Fore femora thickened, pl.37, fig.9 



4. Subgenus Heteromyia 



Off Thorax produced over the head; legs usually quite long; 

 antenna of the male usually with fourteen joints ; that of 

 the female with seven joints. (Go back to ii following i, 

 29 Telrnatogeton, page 90, and read through to 

 qq, M etr iocnem us) 



KEY TO GENERA OF THE NORTH AMERICAN CHIRONOMIDAE 



a Wings rudimentary (Pacific coast), pl.35, figs. 15 to 24 



11. Eretmoptera 

 aa Wings present 



b The M-Cu crossvein present, pl.37, fig.24 



c Antennae with fifteen joints ; both in the male and the female the 

 apical joint oval, pl.27. (Go back to the Group T any pus, 

 f, p. 89, of the preceding key.) 

 cc Antennae with fourteen or fewer joints, when the apical joint is 



oval then antenna with fewer than ten joints 



d Antenna of the male with fourteen joints, the apical joint very 

 long and cylindrical ; antenna of the female with seven or eight 

 joints ; fourth tarsal joint obcordate ; wings bare, pl.30, fig.13 



35. D i a m e s a 



dd Antenna of male with nine joints, short haired ; antenna of female 

 with eight joints. The female does not appear to differ from 

 Diamesa ....... .................. .....36. Eutanypus 



bl) The M-Cu crossvein absent 



c Wing club-shaped, the costal cell thickened, pl.36, fig.7; antenna of 

 male with ten, the female with six joints. .25. Corynoneura 

 cc Not as above 



d Thorax with a longitudinal fissure ; wings black with white mark- 

 ings; antennae seven-jointed in male and female, pl.27, fig.16, 

 and pl.31, fig.16 ..................... 28. Chasmatonotus 



division is called Genus Palpomyia by Kieffer (1902). 

 2 This division is called Subgenus Palpomyia by Kieffer. 



