270 CONNECTICUT GEOL. AND NAT. HIST. SURVEY [Bull. 



Females 



1. Fourth abdominal tergum with a transverse carina at middle; 



thorax usually with two sub-circular yellow spots on each side 



corruptum 

 Fourth abdominal tergum without a transverse carina at middle ; 

 thorax without yellow spots on sides 2 



2. Sides of thorax marked with yellow and black danae 



Sides oi thorax brown or red, sometimes shading into yellow .... 3 



3. Sternum of abdominal segment 8 projecting ventrad and visible 



from the side, the apical margin nearly i mm. below the caudo- 



ventral angles of tergum 8 vicinum 



Sternum of abdominal segment 8 not projecting ventrad or visible 

 from the side ; the apical margin less than i mm. below the 

 caudo-ventral angles of tergum 8 4 



4. Vulvar lamina apparently invisible, there being no division between 



the plates and the caudal margin of the 8th sternum 7 



Vulvar lamina plainly visible, and a distinct division between the 

 plates and the caudal margin of the 8th sternum 5 



5. Legs pale yellowish brown, with black spines ; vulvar lamina with 



an obtuse roimded median notch ambiguum 



Legs black except the ventral surfaces of the front femora ; vulvar 

 lamina with an acute median notch 6 



6. Vulvar lamina less than half as long as sternum 9 rubicundulum 



Vulvar lamina more than half as long as sternum 9 obtrusum 



7. Hind wings, and sometimes the front wings also, chlorinated to 



nodus semicinctum 



Neither front nor hind wings chlorinated to nodus (costiferum) 



Sympetrum corruptum Hagen 



Synopsis of the Neuroptera of North America, 171 : 1861. 



Adult, male. — Color, olive-green, yellow and black, or red and 

 black. 



Head : face, including labium, labrum, front and vertex, yellow, 

 the front with a dark line in front of the ocelli ; occiput and post- 

 genae darker, with lighter spots near the margins of the compound 

 eyes. 



Thorax : dark green or yellow, the caudal lobe of the prothorax 

 bilobed, and with long setae ; mes- and metepimera with more or 

 less faint bluish lines terminating shortly caudo-dorsad of the 

 coxae in small bright yellow spots ; tarsi and claws black, the claws 

 with ventral teeth much shorter than half the length of the claw 

 beyond the tooth; wings large, with little or no yellow at the 

 extreme base; stigma brown in the middle and yellow on both 

 ends ; veins brown. 



Abdomen : but little compressed behind the third segment, grad- 

 ually tapering to tip ; the terga with median transverse ridges on 

 2, 3, and 4; terga mostly brown or yellowish (becoming red) with 

 pale yellow spots on the sides above the lateral carinae ; the mid- 

 dorsum of 8 and 9 with broad black dashes, and a much-reduced 

 one on 10; venter black at bases of segments, the rest pale; supe- 

 rior anal appendages without a large tooth below, the ventral 

 surface forming a fairly even curve with a few small teeth. 



