No. 39] ODONATA OF CONNECTICUT: COENAGRIONIDAE I ©7 



Lestes vigilax Hagen 



Bulletin de rAcademie royale . . . de Belgique. i6: 214: 1862. 



Nymph. — Color light green or brown. 



Head: labium (Fig. 7, No. 4) when folded extending nearly 

 to or between the metacoxae; mental setae five or six, laterals 

 usually three ; marginal spinules of the mentum apparently want- 

 ing or few in number ; teeth of the distal margin of the median 

 lobe and the niesal margins of the palpi are square-tipped, and 

 the furrow representing the median cleft of the median lobe is 

 conspicuous and extends proximad about one-third the length of 

 the expanded portion. 



Thorax : femora and tibiae with rows of short setae, the femora 

 with subapical brown rings, the tips of the tibiae and apical half 

 of the third tarsal segment dark ; wing cases extending about to 

 the middle of the third abdominal segment. 



Abdomen : lateral keels with apical spines on segments 1-9, 

 the spine on segment 9 especially long; gills (PI. i. Fig. 2) long 

 and slender, about equal in width throughout, the apices bluntly 

 pointed ; median gill frequently shorter than the laterals ; ovi- 

 positor nearly reaching the apex of segment 10. 



Measurements: length, 21-30 mm.; length of abdomen, 17- 

 22 mm.; length of gills. 9-11 mm.; width of gills, 1.25-1.75 

 mm. ; length of median lobe, 3.3-4 mm. ; width of median lobe, 

 1.5-2 mm. 



Adult, male. — Color dull metallic green, and buff or yellow. 



Head : dull greenish or black ; labrum brown or blue ; front 

 and vertex metallic green ; occiput and postgenae mostly metallic 

 green, sometimes black and pollinose. 



Thorax : metallic green, yellow below ; prothorax largely black, 

 or metallic green and brown (tenerals) ; mesothorax with green 

 anepisterna and epimera, the mesopleural suture with a brown 

 stripe which becomes black; dorsal carina brown (teneral), black 

 in older specimens ; metathorax yellow except the caudo-dorsal 

 angles of the epistema, but older specimen's frequently obscurely 

 marked with black, and pollinose; legs striped, the coxae and 

 trochanters usually pale; tarsi and claws black, and frequently 

 the tibia also; wings with 15-17 postnodal cross-veins in the front 

 wing ; stigma surmounting two and one-half to three cells. 



Abdomen: green above on terga 1-7 or 8, lateral margins of 

 1-6 pale; segments 9 and 10 usually dark brown or black, 9 and 

 10 becoming pollinose; superior anal appendages (Fig. 12, Nos. 

 12 and 13) dark brown or black, the ventro-mesal margins each 

 with a large subbasal tooth and a rounded indentation about the 

 middle ; between the basal tooth and the indentation are a number 

 of small spinules ; there is a second indentation beyond the median 

 one; inferiors slender, about three-fourths as long as the supe- 

 riors, the basal third greatly enlarged. 



