March, ipii.] Felt: Generic Synopsis of Itonid^. 59 



riarticulate, the distal segment greatly produced or strongly con- 

 stricted. Europe, Asia. 



Genus HYPERDIPLOSIS Felt 1908, type Cecidomyia lobata Felt. 

 Antennie binodose, the circunifili with short, very indistinct loops; 

 palpi quadriarticulate, the claws bent at right angles or nearly so; 

 ventral plate long, deeply and roundly emarginate, the dorsal plate 

 •dilated and with strongly produced angles. North America. 



Genus GIARDOMYIA Felt 1908, type Cecidomyia photophila Felt. 

 The binodose antennal segments of the male with distinct cir- 

 cunifili, the loops extending to the apex of the segment; the claws 

 bent almost at right angles and usually somewhat enlarged sub- 

 apically; ventral plate very long, slender, roundly emarginate, the 

 dorsal plate not greatly enlarged. North America. 



Genus OCTODIPLOSIS Giard 1894, type Diplosis glyccrice Riibs. 

 Distinguished from the preceding by the ventral plate being rather 

 short, deeply and triangularly incised, the dorsal plate broad, deeply 

 and broadly incised. Europe. 



Genus ISODIPLOSIS Riibs. 1910, type /. invohita Riibs. 

 Separated from the preceding genera by the ventral plate being 

 deeply cleft and the thin, smooth terminal clasp segment. Europe. 



Genus METADIPLOSIS Felt 1908, type M. spinosa Felt. 

 Separated from the preceding genera by the claws not being bent 

 at right angles and easily recognized by the short, stout basal clasp 

 segment having a conspicuous triangular, chitinous process at the 

 internal angle, while the terminal clasp segment is short, greatly con- 

 stricted near the middle, enormously swollen and recurved apically. 

 North America. 



Genus EPIDIPLOSIS Felt 1908, type E. sayi Felt. 

 Easily separated from the preceding genus by the long, setose 

 apical process on the basal clasp segment, strongly suggesting the 

 genitalic structure of Lobodiplosis though readily distinguished there- 

 from by the simple claws. North America. 



Genus LESTODIPLOSIS Kieff. 1894, type L. septemgnttafa Kieft". 

 Frail, usually yellowish species with spotted wings. Easily rec- 

 ognized by the triangular lobe at the internal basal angle of the basal 

 clasp segment ; the ventral plate is scarcely longer than broad. Syno- 



