134 MAINE AGRICULTURAL EXPERIMENT STATION. I9IO. 



Tabic of Species. 

 a. Wing 2.40 (or less) times as long as the fore tibia; yellow 

 species, 

 b. Halteres luteous ; siibcosta ends at least the length of 

 the crossvein beyond the latter ; female. 



II. si mi! is n. sp. 

 bb. Halteres with black knob; inferior forceps of hypopy- 

 gium (fig. no) with very short, stout, blunt spines, 

 no palmate spines (compare 12 fasciata Say), 

 c. Subcostal crossvein at distal end of small cell. 



2. glabana n. sp. 

 cc. Subcostal crossvein near middle of small cell. 



d. Small cell (Rj) about one and one-half times 

 as long as wide. 



2a. glabana; var. germana, n. var. 

 dd. Small cell about twice as long as wide ; sub- 

 costa ends less than the length of the small 

 cell beyond the latter. 



2b. glabana; var. socia, n. var. 

 aa. Wing 2.75 (or more) times as long as the fore tibia. 



b. Small species 2.75 mm. in length ; thorax yellow, with 

 three blackish stripes confluent posteriorly, abdom- 

 inal segments fasciate ; inferior forceps lobular, 

 apically with a number of long setas, convex basal 

 part with palmate spines (fig. 115). 



3. nugax n. sp. 

 bb. Larger species, over three mm. long; inferior forceps 

 with two long blunt spines directed mesad (fig. 

 117). 

 c. Thorax mainly yellow, dorsum sometimes with 

 faint indications of fuscous stripes, 

 d. Subcostal crossvein inserted at the base of 

 small cell Rj. 

 e. Dorsal plate of hypopygium produced into 

 a serrate spur, with 3 or 4 long set?e 

 (fig. 109) ; inferior forceps with 2 long 

 blunt spines on dorsal surface ; superior 

 forceps, slender, curved (fig. 109a) : 

 abdomen fasciate. 4. habilis n. sp. 



