28o CONNECTICUT GEOL. AND NAT. HIST. SURVEY [Bull. 



Spinules on inner margin of lateral lobes of labium mostly single; 

 lateral setae ii ; dorsal spine of segment 8 generally somewhat 

 declined, the tip sometimes resting on dorsum of segment 9 . . . . 



(glacialis) 

 5. Length less than 18 mm. ; lateral spines of segment 8 two-fifths 

 to one-half as long as the lateral margin of the segments (not 

 including spine) ; dorsal hooks absent or vestigial ones present 



on some of the segments (hudsonica) 



Length more than 18 mm. ; lateral spines of segment 8 one-sixth 

 to one-fourth as long as the lateral margin of the segment ; 

 dorsal hooks absent (borealis) 



Adult, Males 



1. Hamules without a strong ventrally projecting curved hook at the 



anterior end ; stigma red, or reddish brown glacialis 



Hamules with a strong ventrally projecting hook at anterior end; 

 stigma black, or dark brown 2 



2. Sides of labial palpi white proxima 



Sides of labial palpi black 3 



3. Abdomen with seventh segment black frigida 



Abdomen with pale spot on seventh segment 4 



4. Terga 4 and 5 black or with yellow streaks on mid-dorsum; infe- 



rior anal appendage broad at tip, the distal margin rounded, .intacta 

 Terga 4 and 5 with red spots on dorsum; inferior anal appendage 

 broad at tip, the distal margin angular hudsonica 



Females 



1. Abdomen with a yellow dorsal spot on tergum 7 2 



Abdomen without a yellow dorsal spot on tergmn 7 3 



2. Plates of the vulvar lamina in contact on the meson hudsonica 



Plates of the vulvar lamina separated from one another by the 



width of each plate intacta 



3. Labium black _ 4 



Labium with a pale spot on each side proxima 



4. Plates of the vulvar lamina almost in contact on the meson, the 



median notch acute frigida 



Plates of the vulvar lamina separated by a broad quadrangular 

 excavation glacialis 



Leucorrhinia frigida Hagen 



Transactions of American Entomological Society, 17: 231: 1890. 



Nymph. — Labium with 10 lateral setae and 9 mental setae. 

 Teeth of palpi shallow^, each with a single long spine and a smaller 

 one alongside; distal margin of mentum subangulate; caudal 

 margins of head rounded, the lateral surface sparsely and evenly 

 setose ; dorsal surface smooth. 



Thorax: hind femora extending to abdominal segment 7. 



Abdomen : with dorsal spines on segments 3-8 inclusive ; lateral 

 spines on 8 and 9, the lateral margins setose, the spines of 9 

 extending to the tips of the terminal appendages ; length of termi- 

 nals plus segment 10, about as long as, or a little longer than 

 segment 9 measured on ventro-meson. 



Measurements ; immature nymph : total length, 14 mm. ; length 

 of abdomen, 7 mm. ; length of metathoracic wing-cases, 2 mm. 



