LEUCTRA. 37 



Hah. Washington (Osten Sacken) ; Nova Scotia (Redman) 

 Is not the ferruginous-colored species of Mr. Walker distinct from 

 this? 



3. N. perfecta! 



Nemoura perfecta Walk.! Catal. 191, 51. 



Black, shining ; head broader than the prothorax, antenna? black, 

 prothorax narrower behind, sides oblique, anterior angles rounded, 

 the anterior margin a little recurved, disk with a few tubercles ; 

 feet testaceous, femora exteriorly and the tarsi brownish-black ; 

 wings clouded with fuscous, broadly margined with fuscous, veins 

 fuscous. 



Length to tip of wings 8 millim. Alar expanse 14 millim. 



Hob. Trenton Falls (Osten Sacken) ; Nova Scotia (Redman). 

 It may be different from Mr. Walker's species. 



I possess an individual of the European N. variegata, labelled 

 "Philadelphia," but the label is very doubtful. 



LEUCTRA Stephens. 

 Wings veiny, involuted when in rest, transverse veins very few, 

 very regular, veins of the pterostigma simple (*. e., not forming 

 an X); anal area of the posterior wings small, plicate; caudal setae 

 absent ; the second articulation of the tarsi short. 



1. L. tenuis ! 



Nemoura tenuis Pict.! Perl. 375, 10; tab. xlix, fig. 1 — 3. 



Fuscous, opaque, head a little broader than the prothorax; an- 

 tennae fuscous ; thorax quadrangular, sides straight, angles sub- 

 acute, disk with three elevated lines, the middle one straight, the 

 others subincurved; feet fulvous, abdomen fuscous; wings subhy- 

 aline, a little ciliated, veins fulvous. 



Length to tip of wings 1 millim. Alar expanse 12 millim. 



Hah. Philadelphia ; Washington (Osten Sacken) ; Sharon 

 Springs, New York, in August (Osten Sacken). 



2. L. ferruginea! 



Nemoura ferruginea Walk.! Catal. 183, 18. 



Fusco-ferruginous, somewhat shining ; head a little broader 

 than the prothorax ; antennas ferruginous ; prothorax a little 



