PLECOPTERA OF NORTH AMERICA 213 



Wash. (J. C. Bradley); March-June, Seattle, Wash.; 

 April-May, Olympia, Wash. (Trever Kincaid) ; July 15, 

 1920, Paradise Valley, Mt. Rainier, Wash. ; May 20, 1921, 

 Yosemite Valley, Calif. (E. C. VanDyke) ; June 16, 1911, 

 Hills back of Oakland, Calif. (E. C. VanDyke) ; July 7, 

 1916, Eldorado Co., Calif. (A. C. Brown) ; Aug. 3, 1921, 

 Fern Lake, Estes Park, Colo. (P. W. Claassen) ; Boulder, 

 Colo. (G. S. Dodds) ; June 25, 1913, Long's Peak Trail, 

 Colo. (T. D. A. Cockerell) . 



Nemoura oregonensis Claassen. 



(Plate 37, figs. 9-11.) 

 1923. Nemoura oregonensis Claassen, Can. Ent., 55:288. 



Length to tip of wings, male, 9.5 mm. Expanse, male, 

 16 mm. 



General color brown with banded legs and wings. Head 

 wider than prothorax, brown, with a black spot beside the 

 eyes just in front of hind ocelli; rest of head somewhat 

 mottled; hind ocelli closer to eyes than to each other. 

 Prothorax brown, quite rugose ; the rugosities blackish ; 

 wider than long, narrowed behind; angles very broadly 

 rounded. Legs dark brown ; femora with a light trans- 

 verse band just beyond the midlle. Wings infuscated, 

 with a light transverse band before the cord and one be- 

 yond ; anal field of hind wings large. Four finger-like gills 

 in the cervical region. 



Male. Subanal lobes very wide, almost as wide as long, 

 truncate, and bearing on the inside (ventral view) a small 

 tooth ; cerci short, membranous ; supra-anal process re- 

 curved, greatiy enlarged, partly membranous, armed be- 

 low with a double row of spines, above also with a few 

 spines; subgenital plate short; ventral lobe truncate, 

 about two and one-half times as long as wide. 



Female. Unknown. 



Holotype, male, June 21, 1922, Blitzen Valley, Harney 

 Co., Ore. (W. J. Chamberlin, Cornell University Collec- 

 tion). 



Nemoura trispinosa Claassen. 



(Plate 37, figs. 12-15.) 

 1923. Nemoura trispinosa Claassen, Can. Ent., 55:289. 



Length to tip of wings, male, 8.5 mm. ; female, 9 mm. 

 Expanse, male, 14.5 mm. ; female, 16.5 mm. 



General color blackish brown. Head considerably wider 

 than prothorax; hind ocelli about twice as close to eyes 

 as to each other. Prothorax slightly rugose, wider than 



