503 



Males 



a. Wings smoky fumipennis. 



aa. Wings not smoky. 



b. Stigma surmounting more than one cell in both wings ; abdominal 



terga 8-10 black with dorsal spots of brown, or entirely black 



moesta putrida. 



bb. Stigma surmounting one cell or less ; terga 8-10 inclusive or nine 

 and ten, blue, never black except the eighth, and never with brown 

 markings. 



c. Terga nine and ten blue sedula. 



cc. Terga eight, nine, and ten blue. 



d. Black stripe of the mesopleural suture extending from the 

 mesinf raepisternum to the wing bases. 



e. Terga 1-5 with the pale color of the dorsum limited to a 

 very narrow mesal line and narrow basal rings tibialis. 



ee. Terga 1-5 with the pale color of the dorsum occupying the 

 greater portion of the segments, the black confined to small, 

 apical, lateral spots on 1-4 and an apical ring in addition on 



the fifth violacea. 



dd. Black stripe of the mesopleural suture extending much less 

 than half-way from the mesinf raepisternum to the wing bases. . 

 apicalis. 



Argia apicaus (Say) 



Nymph. — Color, dark brown. 



Head one-third wider than long, pentagonal, the caudo-lateral 

 angles strongly projecting and armed with heavy setae; eyes black; 

 antennae dark brown except the first and the last two or three seg- 

 ments; labium very broad, the median lobe dark in color, without 

 mental setae but with about twelve marginal setae; labial palpi with 

 three or four setae on the proximal segment and with a long movable 

 distal segment much longer than the fixed hooks ; labium, when folded, 

 extending caudad of the procoxae, but not reaching the mesocoxae. 



Thorax dark in color; legs conspicuously banded, the dark por- 

 tions consisting of the second segment of the trochanters, two broad 

 bands on each femur and three on each tibia, the proximal one on 

 the tibiae being narrow, the next one slightly broader and located 

 about the middle, and the third nearly equal in width to the median 

 band and covering the apex; tarsi of the usual form, dark brown in 

 color ; wing-cases extending caudad to the middle of the fifth abdominal 

 segment. 



