March, igii.] FeLT : GENERIC SYNOPSIS OF ItONID.E. 61 



lobes of the dorsal plate are short, truncate, the hair whorls on the 



female antenn?e are erect. Europe. 



■Genus PARALLELODIPLOSIS Riibs. 1910, type Diplosis galliperda F. Lw. 



The long ventral plate is narrowly rounded apically, while the 

 basal antennal node in the male is simple, the distal double. To this 

 genus belong forms previously referred by the writer to Clinodiplosis 

 Kieff. Europe, North America, 'and probably South America. 



Genus XENODIPLOSIS new name, type Allodiplosis laviusculi Riibs. 



Distinguished at once from the preceding and probably from all 

 ■other Itonidinarise by the basal node of the flagellate antennal seg- 

 ments in the male being double, the distal simple. Allodiplosis Riibs., 

 Sept., 1910, preoccupied by Allodiplosis Kieff. & Jorg., July, 1910. 

 Genus OBOLODIPLOSIS Felt 1908, type Cecidomyia orbiculata Felt. 



The terminal clasp segment is greatly produced, being nearly one 

 lialf longer than the basal clasp segment; the dorsal plate is greatly 

 ■expanded, nearly divided, the lobes orbicular, while the ventral plate 

 appears to be widely separated, the two lobes being short, stout and 

 roundly triangular. North America. 



Genus ITONIDA Meign. 1800, type Tipiila pini DeG. 



Antennal segments 14; three distinct circumfili, the nodes unequal; 

 palpi quadriarticulate, the third vein uniting with the margin well 

 beyond the apex of the wing; the pulvilli longer than the simple claws; 

 the dorsal and ventral plates of the male genitalia deeply bilobed; 

 •ovipositor rather long, the lobes narrowly oval. Distribution prob- 

 ably world-wide. 



Genus ACODIPLOSIS Kieff. 1895, type Cecidomyia imdcr H. Lw. 



Palpi triarticulate; pulvilli longer than the claws. Easily recog- 

 nized by the second antennal segment with a distinct tooth or ventral 

 spine. ?jynonym: Arthroccrastis 'R.nhs. Europe. 



Genus ODONTODIPLOSIS Felt 1908, type Cecidomyia kanierensis Felt. 



Distinguished from the preceding by the pulvilli not being longer 



than the claws and the absence of a distinct tooth or ventral spine 



on the second antennal segment. Peculiar because of the somewhat 



conical ventral plate or harpes with serrate margins. North America. 



Genus ADIPLOSIS Felt 1908, type Cecidomyia toxicodendri Felt. 

 Easily separated from the preceding genus by the ventral plate 



