MAY FLIES AND MIDGES OP NEW YORK 89 



Imagines 



Note. — In counting the antemial joints the large basal joint is included, 

 but not the hidden first joint. 



a Wings absent or rudimentary 



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

 with seven joints, mouth parts rudimentai*y, pl.36, fig.l3, female 



14. C 1 u n i o 



66 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 ; anteima of the female four-jointed, of the male 



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



dd Palpi two-jointed ; antenna of the female six-jointed 



c Second joint of antenna lilce those following, monilliform, pi. 37, 



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



cc Second joint longer than those following ; male antenna also 

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

 a a Wings present 



6 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, pl.30, flg.l3, male 



35. D i a m e s a 

 dd Not as above 



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

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



( Group T any p u s ) 

 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, Rj 



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



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

 teen joints, Ra indistinct (Australian genus) 



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



gg Fork of cubitus petiolate 19. 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, pi. 37, 



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



cc Antennae with less than ten joints 



d Crossvein near basal third of wing, pi. 37, fig.ll. Antennae about 

 eight-jointed (Chile) 21. Podonomus 



