MAY FLIES AND MIDGES OF NEW YORK 89 



Imagines 



NOTE. In counting the antennal joints the large basal joint is included, 

 but not the hidden first joint. 



o Wings absent or rudimentary 



& Wings reduced to mere vestiges, legs short and not slender, antenna 

 with seven joints, mouth parts rudimentary, pl.36, fig.13, female 



14. Clunio 

 && Rudimentary wings reaching at least to the end of the first abdominal 



segment 



c Halteres wanting, wings in the form of a flattened racket, tarsal 

 claws with a little subapical tooth. Palpi four-jointed ; antenna 



five (?) jointed 10. B e 1 g i c a 



cc Halteres distinct 



(I Palpi four-jointed ; antenna of the female four-jointed, of the male 



six-jointed, pl.35, figs. 16, 21, 22 11. E r e t in o p t e r a 



</(/ Palpi two- jointed ; antenna of the female six-jointed 



e Second joint of antenna like those following, inonilliforin, pi. 37, 



figs. 5, 6, 7 12. II a 1 i r y t u s 



ee Second joint longer than those following ; male antenna also 

 with six joints, pl.35, figs. 4 to 9. ..13. , P s a ni a t h i o m y i a 

 a a Wings present 



& The M-Cu crossvein present (i. e., cell M closed by a vein), pi. 37, fig.24 

 c Antenna with twelve or more joints 



d Antenna with .fourteen joints usually plumose; fourth tarsal joint 

 usually shorter than the fifth ; wing bare, pi. 30, fig.13, male 



35. D i a m e 8 a 

 dtl Not as above 



c Antennae with, fifteen joints both in male and female ; plumose 

 in the former ; the vein M simple, pi. 27, figs. 1 to 15 



(Group T any p us) 

 f Wing bare 



g Fork of the cubitus petiolate 15. P r o c 1 a d i u s 



gg Fork of cubitus proximad of crossvein 



16. A n a t o p y n i a n. gen. 

 ff Wing pubescent 



g Fork of cubitus proximad of crossvein 



h Antennae of male and female each with fifteen joints, U, 



and R 3 distinct 17. A b 1 a b e s m y i a n. gen. 



//// Antennae of female with twelve joints, the male with fif- 

 teen joints, R 3 indistinct (Australian genus) 



18. I s o p 1 a s t u s 



gg Fork of cubitus petiolate 10. T a n y p u s 



ee Antennae with twelve or fourteen joints ; wings hairy ; cubitus 

 not forked; anterior crossvein long and very oblique, pl.37, 



fig. 16 20. P e n t a n e u r a 



cc Antennae with less than ten joints 



d Crussvein near basal third of wing, pl.37, fig.ll. Antennae about 

 eight-jointed (Chile).. 21. Podonoinus 



