412 NEW YORK STATE MUSEUM 



c Abdomen dark red, the segments margined with fuscous, length 

 I mm ; 5th antennal segment having the stems with a length 2]/^ 

 and 4 times that of the diameters, respectively, trinodose 



(Cecidomyia) subtruncata Felt, C. 506 



cc Abdomen fuscous brown, length i mm ; 5th antennal segment having 



the stems with a length i^ and 3 times that of the diameters, 



respectively montana n. sp., C. 631 



aaaa Ventral plate long, emarginate 



b Ventral plate tapering distally, roundly emarginate 



c Dorsal plate short, roundly emarginate, the 5th antennal segment 

 having the stems with a length i^ and 2^ times that of the 



diameters; bred from roots of Cattleya gigas 



cattleyae n. sp., C. 979 



cc Dorsal plate short, narrowly and triangularly emarginate, the 



lobes produced laterally ; abdomen yellowish, length i mm ; 5th 



antennal segment having the stems with a length 2^ and 3^ 



times that of the diameters r u b i s o 1 i t a n. sp., C. 656 



hh Ventral plate long, slender, broadly emarginate 



c Dorsal plate triangularly emarginate, the lobes truncate 



d Abdomen reddish brown, length .75 mm ; 5th antennal 'segment 

 having the stems with a length 3 and 4 times that of the 



diameters extensa n. sp., C. 228 



bhh Ventral plate long, broad, scarcely tapering, very broadly emarginate 

 c Dorsal plate short, triangularly emarginate, the lobes truncate 

 d Abdomen a fuscous reddish brown, length 1.5 mm ; 5th antennal 

 segment having the stems equal, each with a length 3]^ times 



its diameter pratensis n, sp., C. 741 



dd Abdomen reddish brown, length 1.25 mm; 5th antennal segment 

 having the stems with a length i^ and 23^ times that of the 

 'diameters (Cecidomyia) c ar p i n i Felt, C 347 



CECIDOMYIA Meig. 



This, the oldest genus of the group, originally included all forms 

 referable to this family. It is at present restricted to a large number 

 of Diplosids having simple claws, the third vein uniting with costa 

 beyond the apex and not presenting characters given for the pre- 

 ceding genera. The members of this group appear to live largely in 

 leafy tissues, though one form, Cecidomyia resinicola 

 O. S., occurs in exuded pitch masses. This genus includes the wheat 

 midge, Cecidomyia tritici Kirby, a species of prime eco- 

 nomic importance. 



Key to species 

 a Ventral plate long 



h Ventral plate broadly and roundly emarginate, the lobes diverging 

 strongly 

 c Fifth antennal segment having the basal portion of the stem with a 

 length less than its diameter, the circumfili indistinct or wanting 



