202 THOMAS SAY FOUNDATION 



Nemoura glabra Claassen. 



(Plate 34, figs. 1-4.) 

 3923. Nemoura glabra Claassen, Can. Ent., 55:281. 



Length to tip of wings, male, 7 mm.; female, 7.5 mm. 

 Expanse, male, 11 mm.; female, 14 mm. 



General color dark brown. Head wider than prothorax ; 

 hind ocelli closer to eyes than to each other. Prothorax 

 much wider than long, moderately rugose, widened be- 

 hind, angles broadly rounded. Wings lightly to rather 

 heavily infuscated, with two indistinct transverse darker 

 bands ; anal field of hind wings large. Gills apparently 

 absent. 



Male. Subanal lobes entire, unmodified ; cerci large, 

 membranous ; supra-anal process recurved, long, not much 

 widened, smooth and completely chitinized; subgenital 

 plate short ; ventral lobe about twice as long as wide. 



Female. Seventh sternite unmodified ; eighth sternite 

 not produced but with a suggestion of a slight notch in 

 center. 



Holotype male, allotype female, April 30, 1913, Truro, 

 Nova Scotia (Cornell University Collection) ; one female 

 and male, same locality as type ; male and female, March, 

 1908, Boulder, Colo. ; one male, Logan, Utah. 



Nemoura frigida Claassen. 



(Plate 34, figs. 5-7.) 

 1923. Nemoura frigida Claassen, Can. Ent., 55:285. 



Length to tip of wings, male, 7 mm. Expanse, male, 

 12 mm. 



General color dark brown. 



Head wider than prothorax, smooth, covered with fine 

 pile; the hind ocelli at least twice as close to eyes as to 

 each other. 



Prothorax wider than long, much narrowed behind, 

 quite rugose, uniformly brown, angles quite sharp. Legs 

 uniformly light brown. Wings uniformly subhyaline; 

 anal field of hind wings large. Gills present. 



Male. Subanal lobes entire, somewhat produced and 

 broadly truncate behind; cerci membranous and small; 

 supra-anal process recurved, enlarged and largely mem- 

 branous; subgenital plate only moderately produced; 

 ventral lobe about three times as long as wide. 



Female, unknown. 



Holotype, male, June 16, 1899, Sitka, Alaska (Harri- 

 man Expedition, T. Kincaid) ; in the National Museum, 

 Washington, D. C. 



