204 THOMAS SAY FOUNDATION 



Nemoura delicatula Claassen. 



(Plate 34, figs. 14-17.) 



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



Length to tip of wings, male, 6 mm. ; female, 7.5 mm. 

 Expanse, male, 10.5 mm. ; female, 13.5 mm. 



General color light brown. Head much wider than pro- 

 thorax, brown ; hind ocelli closer to eyes than to each 

 other. Prothorax brown, quite rugose; wider than long; 

 angles very broadly rounded. Legs light brown. Wings 

 uniformly hyaline, veins faint; anal area of hind wings 

 narrow. Gills absent. 



Male. Subanal lobes slightly, if at all, modified; cerci 

 small, membranous ; supra-anal process recurved, broadly 

 truncate at tip, fitting closely into a depressed area at the 

 tenth tergite, partly membranous and bearing above two 

 chitinous projections; the tenth tergite each side with a 

 raised chitinized lobe ; subgenital plate rather short ; ven- 

 tral lobe about three times as long as wide. 



Female. Seventh sternite not produced posteriorly; 

 eighth sternite unmodified, the genital opening not 

 guarded by valves. 



Holotype, male, allotype, female, and 24 paratypes, 

 males and females, from Boulder, Colo. (G. S. Dodds, Cor- 

 nell University Collection). 



Nemoura bifurcata Claassen. 



(Plate 34, figs. 18-20.) 

 1923. Nemoura bifurcata Claassen, Can. Ent., 55:282. 



Length to tip of wings, male, 9 mm. Expanse, male, 

 14.5 mm. 



General color brown. Head a little wider than pro- 

 thorax, occiput somewhat rugose ; hind ocelli about twice 

 as close to eyes as to each other. Prothorax brown, a 

 little wider than long, hardly narrowed behind; angles 

 rather sharp; surface somewhat rugose. Legs brown. 

 Wings uniformly subhyaline; anal field of hind wings 

 large. Gills apparently absent. 



Male. Subanal lobes considerably produced and deeply 

 bifurcate at the tip ; cerci membranous ; supra-anal proc- 

 ess recurved, membranous above and dorsally finely spinu- 

 lose ; subgenital plate rather short ; ventral lobe about two 

 and one-half times as long as wide. 



Female, unknown. 



Holotype, male, 5-15-95, without locality label (Cornell 

 University Collection). 



