489 



Thorax similar to that of the male excepting that the dorsal carina 

 and mesopleural suture show distinct brown; legs with one dorsal 

 black stripe, frequently reduced to a row of spots; wings with the 

 stigma surmounting slightly less than three cells. 



Abdomen with lateral, marginal, pale stripes on all terga, the 

 stripes as a rule broader than those of the male; anal appendages of 

 the usual type, the superiors pale, slightly darker at the tips; ovipositor 

 long, the lateral valves widely separated from the tenth segment at the 

 apex, the ventral half, or more, black; prostyles slender, bent ventrad 

 at the tips, and with a black dorsal stripe ; sternites of the eighth seg- 

 ment large, the caudo-dorsal angles acute. 



Measiircmcnis 



Length, $ 54 mm. 



Length, 2 49 mm. 



Length of abdomen, S 43 mm. 



Length of abdomen, 2 38.5 mm. 



Length of hind wings, S 29 mm. 



Length of hind wings, 2 28 mm. 



Width of hind wings, $ 6.5 mm. 



Width of hind wings, 2 5.5 mm. 



Described from two males and two females in the collection of 

 Mr. E. B. Williamson. 



Not taken in Illinois by the writer, but reported by Walsh ('62) 

 from the vicinity of Rock Island. The species is closely related to 

 z'igilax, but is distinguishable from the latter by the pale occiput and 

 the long inferior anal appendages of the male. 



Lestes rectangularis Say 



Nymph. — Color, buff or pale green. 



Head elliptical, the width much greater than the length ; eyes dark ; 

 caudo-lateral margins of the head without setae; labium extending 

 caudad^ between the metacoxae; mental setae six; lateral setae three, 

 two being on the distal segment of the palpus. 



Thorax : mesothorax and metathorax much wider than the pro- 

 thorax; legs slender, the femora with longitudinal rows of minute 

 setae, the apices of all the femora fuscous and with a subapical dark 

 ring; tibiae with small setae arranged in rows and with fuscous apices; 

 tarsi with the apical half of the third segment and the claws dark 

 brown, the hind tarsi with a very long apical segment and a very short 

 proximal one. 



