1913] North American Dipterous Genus Neiirigona 59 



31 Neurigona albospinosa n. sp. 



Figure 32. 



Thorax blackish, with three metalHc brown vittse; abdomen green- 

 ish black, segments gray pollenose at base ; hypopygium small, testaceous ; 

 hind cox^ with several rather weak whitish bristles. Length of male 

 4-4^ mm., female 3 J/2 -5 mm. 



Male : Face not very narrow for a male, and with the sides nearly 

 parallel ; face and palpi white. ; proboscis and antennae yellow, the latter 

 with the third joint and the arista dark brown; front and occiput dark 

 grayish green with white pollen; orbital cilia white. Thorax and scutel- 

 lum blackish, more gray on the dorsum, and with three somewhat 

 shining metallic brown vittae, the central one between the acrostichal 

 bristles most sharply defined ; thorax including scutellum and metanotum 

 whitish pollenose, the pollen more brown on the flattened space before 

 the scutellum, this brown pollen extends somewhat onto the scutellum. 

 Abdomen metallic greenish black with coppery reflections, and a grayish 

 pollenose band at the base of each segment; the hairs on these bands 

 white, on the posterior part of the segments the hairs are black; the 

 first segment wholly gray pollenose, and with the marginal row of 

 bristles pale except about four at the top which are black; second seg- 

 ment with two transverse rows of black dashes near the base; venter of 

 the first segment, and very narrow lateral edges of one or more of the 

 others yellow; hypopygium testaceous, polished, and rather small. 

 Legs pale yellow ; front coxae whitish with long white hairs on the whole 

 front; middle cox« also with white hairs and bristles; hind coxae with 

 one long and several weak whitish bristles on the outside; middle and 

 hind coxae blackish at base; front and middle metatarsi about two- 

 thirds as long as their tibiae; hind tarsi with the first joint shorter than 

 the second; middle and hind tarsi infuscated fromi the tip of the first 

 joint; hind femora brownish above. Cilia of the tegulee whitish; halters 

 yellow with the knob whitish. Wings brownish hyaline, darker along 

 the front; third and fourth veins wide apart at tip. 



Females : Agrees with the male in most characters, but the scutel- 

 limi yellow, sometimes a little darkened at base; marginal row of 

 bristles on the first segment of abdomen black, sometimes one or two of 

 the lower ones yellowish; stout bristles on hind coxae brown in some 

 lights. Face broad, darker than in the male, and the palpi yellowish. 



Described from seven males and twelve females, from 

 Idaho, Wash., and Cal. I received from Prof. Aldrich specimens 

 taken at Lewiston, and Juliaetta, Idaho, the latter taken 

 May 7th; also specimens taken at Stanford University, Cal., 

 Feb. 22 to March 24th. From Prof. Melander I received 

 specimens from Wenatchee, Wash., taken May 8th. 



