No. 39] ODONATA OF CONNECTICUT: COENAGRIONIDAE 95 



Lateral keels of segments 3-9 or 4-9 with apical spines ; gills 

 unequal in width and usually narrowed considerably beyond the 



middle forcipatus 



rectangularis 



Adults, Males 



1. Dorsum of thorax and usually abdomen, metallic green 2 



Dorsum of thorax and abdomen dark brown or black 5 



2. Inferior appendages more than half the length of the superiors, 



but never longer than the latter 3 



Inferiors either longer than the superiors or less than half their 

 length • . 4 



3. Inferiors long and slender; length of abdomen 34-38 mm vigilax 



Inferiors broad and flat; length of abdomen 26-28 mm uncatus 



4. Inferiors less than half the length of the superiors; wings flaves- 



cent" eurinus 



Inferiors longer than the superiors (Fig. 12, No. 9) ; wings not 

 flavescent inaequalis 



5. Inferiors shorter than half the length of the superiors (Fig. 12, 



Nos. I and 2) ; metepimera with black spots near the latero- 



ventral carinae congener 



Inferiors more than half the length of the superiors ; metepimera 

 without black spots near the latero-ventral carinae 6 



6. Inferiors sigmoid, the apical two-thirds curved in an opposite 



direction from the superiors unguiculatus 



Inferiors not sigmoid, the apical two-thirds not curved in an oppo- 

 site direction to the superiors 7 



7. Metapleural suture covered with a sooty black stripe disjunctus 



Metapleural suture not covered with a sooty black stripe 8 



8. Basal tooth of the mesal margin of the superiors longer than the 



tooth of the distal third forcipatus 



Basal tooth of the mesal margin of the superiors shorter than the 

 tooth of the distal third (Fig. 12, Nos. 11 and 12) ...rectangularis 



Females 



1. Dorsum of thorax green in color, or with green stripes 2 



Dorsum of thorax black or dark brown, never green 5 



2. Greatest width of thorax in dorsal view 3.75-4 mm. ; green stripe 



of mesepisterna not so wide as the brown stripe covering the 



dorsal carina eurinus 



Greatest width of thorax less than 3.75 mm. ; green stripe of each 

 mesepisterna wider than the brown stripe of the carina 3 



3. Occiput and postgenae pale inaequalis 



Occiput and postgenae black, or green 4 



4. Total length about 35 mm. ; stigma always surmounting less than 



three cells uncatus 



Total length 43-47 mm. ; stigma usually surmounting three or 

 more cells vigilax 



5. Metepimera with a black spot above and below the latero-ventral 



carinae congener 



Note. — Lestes eurinus has not been included in the key to nymphs, although the 

 nymph is known and has been reared by Walker. According to that author it differs 

 from those mentioned in the key in being much larger, and the mentum being provided 

 with 7 to 8 mental setae instead of 6 to 7 in most others. Disjunctus is also omitted, 

 which seems to be most closely related to uncatus, though differing in the length of the 

 female ovipositor. 



'" Sometimes with little or no coloration. 



