THE CANADIAN ENTOMOLOGIST 109 



— Thorax largely or entirely blackish 23. 



23. Arista with its longest hairs about equal m length to width of third anten- 



nal segment; hind femur with one or two long bristles at middle on pos- 

 teroventral surface obscurinervis Stein 



— Arista with its longest hairs about as long as its basal diameter; hind femur 



without bristles at middle on posteroventral sur- 

 face ncopoeciloptcra Malloch 



24. Hind tibia with one setula near base on posterodorsal surface sp. 



— Hind tibia with three or four setulae on posterodorsal surface 25. 



25. Only the fore femora infuscated ; antennae with second segment and base 



of third ferruginous; longest hairs on arista longer than width of third 

 antennal segment ; fore tibia with one posterior bristle ; mid tibia with- 

 out an anterodorsal bristle abicns Stein 



— Mid and hind femora as well as fore pair infuscated at bases; antennae en- 



tirely black ; longest hairs on arista a little shorter than width of third 

 antennal segment; fore tibia with one anterodors?! and usually two pos- 

 terior bristles; mid tibia with an anterodorsal 

 bristle nigribasis Malloch 



— Only the fore femora infuscated; antennae with second segment reddish; 



longest hairs on arista distinctly shorter than width of third antennal 

 segment spuria Malloch 



Helina hannai sp. n. 



Male and Fcuialc- — Black, almost glossy. Orbits and cheeks with white 

 pruinescence, frontal stripe opaque black ; antennae and pal])i black. Thorax 

 indistinctly trivittate. Abdomen with brownish gray pruinescence, and a con- 

 tinuous dorsocentral black vitta. Legs black. Wings slightly fuscous, bases 

 of veins yellow. Calyptrae bright yellow. Knobs of halteres black. 



Eyes of male separated by about one tenth of the head-width ; arista very 

 pubescent ; eyes almost bare. Thorax with 4 pairs of postsutural dorsocentral 

 bristles ; prealar bristle long. Abdomen subcylindrical, slightly tapered at apex ; 

 hypopygium small. Fore tibia with two or three setulae on posteroventral sur- 

 face; mid tibia with two posterior bristles; hind tibia with two anterodorsal and 

 two anteroventral bristles ; hind femur with a continuous series of long bristles 

 on anteroventral surface and some on basal half of posteroventral. 



Fcuiale. — Frons over one third of the head-width; arista pubescent as in 

 male. 



Length, 6.5 — 7.5 mm. 



Type. — St. George Island, Behring Straits, June 24, 1914. Allotype and 

 two paratypes, same data as type ; one male paratype and puparium. same locality, 

 June 20, 1913; one male, June 10. 1914; one male and two females. June 17, 1914 

 (G. D. Hanna). 



Named in honor of the collector. 



Type in collection of L'nited States Bureau of Biological Survey. 



