232 THOMAS SAY FOUNDATION 



25, 1897; one female, Three Bros. Mts., Olympic Range, 

 Wash., Aug. 15, 1908 (J. C. Bradley). 



Leuctra sibleyi Claassen. 



(Plate 40, figs. 15, 1G; plate 42, fig. 11.) 

 1923. Leuctra sibleyi Claassen, Can. Ent., 55:262. 



Length to tip of wings, male, 8.5-9.5 mm.; female, 

 9.5-11 mm. Expanse, male, 14.5-15.5 mm.; female, 16-20 

 mm. 



General color brown. Head wider than prothorax; oc- 

 ciput somewhat rugose and mottled with darker brown; 

 hind ocelli between two and three diameters distant from 

 eyes. Prothorax wider than long, brown; angles broadly 

 rounded ; median longitudinal field at least one-fifth the 

 width of pronotum; disc of pronotum quite rugose, the 

 rugosities darker. Legs brown. Wings subhyaline to 

 brownish infuscated. 



Male. Anterior margin of eighth tergite heavily chiti- 

 nized and bearing two, long, slender, widely separated 

 raised, chitinous processes which reach over the entire 

 eighth tergite ; supra-anal lobe rounded behind ; cerci un- 

 modified; subanal lobes quite long and slender; titillators 

 slender, nearly straight ; shorter than subanal lobes ; ven- 

 tral lobe at least twice as long as wide. 



Female. Eighth abdominal sternite somewhat pro- 

 duced into a bilobed hairy subgenital plate with a small 

 median notch. 



Holotype, male, allotype, female, May 16, 1922, Moore's 

 Brook, Ithaca, N. Y. (C. K. Sibley, in Cornell University 

 Collection) , five males, ten females, May 16, 1922 ; three 

 males, one female, May 15, 1915, Taughanic, Ithaca, N. Y. 



Leuctra tenuis Pictet. 



(Plate 40, figs. 7, S; plate 42, fig. 5.) 



1842. Nemoura tenuis Pictet, Ins. Neur., 375. 



1861. Leuctra tenuis Hag., Syn. Neur. N. A., 37. 



1892. Leuctra tenuis Banks, Cat. Neurop. p 343. 



1904. Leuctra tenuis Banks, Proe. Ent. Soe. Wash., 6:206. 



1907. Leuctra tenuis Banks, Cat., 15. 



1901. Leuctra tenella Needham, Bull. X. Y. State Mus. 47:416. 



Length to tip of wings, male, 6.5-7 mm. ; female, 8 mm. 

 Expanse, male, 11-12 mm.; female, 13 mm. 



General color brown to blackish brown. Head wider 

 than prothorax, pilose ; hind ocelli between two and three 

 diameters distant from eyes. Prothorax quadrangular, a 

 little wider than long ; angles rounded ; median longitu- 



