No. 39] ODONATA OF CONNECTICUT: LIBELLULIDAE 289 



Key to Genera i 



Nymphs 



I. Movable hook of the labial palpi long and slender, setiform ; lateral 

 spines of the eighth abdominal segment longer than those on 

 segment 9 and extending beyond the caudal margin of that seg- 

 ment (PI. TV, Fig. 2) Tramea, p. 289 



Movable hook of the lateral arms hardly longer than the teeth, 

 especially the two next the movable hook; spines of the eighth 

 abdominal segment not usually extending beyond the caudal 

 margin of that segment Pantala, p. 292 



Adults 



I. Abdomen without transverse median carina on segment 5; not 

 more than two transverse carinae on segment 3; veins M2 and Rs 

 not conspicuously sinuate at middle (PI. xv. Fig. 2) Tramea, p. 289 

 Abdomen with transverse median carina on segment 5 ; also three 

 prominent transverse carinae on segment 3 ; veins M2 and R 

 conspicuously sinuate at middle (PI. xv. Fig. i) ...Pantala, p. 292 



Genus Tramea Hagen 



Nymphs. — Head with lo-ii setae on the palpi; 14-15 mental; 

 abdomen without dorsal hooks, the lateral spine on segment 8 

 longer than on 9; anal appendages not decurved, the superior 

 suddenly contracted beyond the basal third. 



Adults. — Ten or more antenodal cross-veins in the front wing; 

 proximal and distal margins of the stigma not parallel, the stigma 

 about three times as long as broad and supported by i to 2 cross- 

 veins ; Mj not sinuate ; triangle 3-sided, considerably farther dis- 

 tad in the front wing ; subtriangle absent ; CUj arising exactly 

 from the caudal angle of the triangle in the hind wings ; caudal 

 margin of the pronotuin entire ; male abdomen without hooks on 

 the venter of the first abdominal segment ; transverse median 

 carinae on abdominal terga 2, 3 and 4; general color dark brown 

 to black. 



The adults of this genus that I have seen on the wing were 

 skimming over the surfaces of small ponds or lakes and were 

 exceedingly difficult to capture. No nymphs from Connecticut 

 have been seen but there is little doubt that they occur in the 

 waters about which adults have been seen. They live in sub- 

 merged vegetation. 



Byers, C. F. (Jour. N. Y. Ent. Soc. 35 : 73: 1927) has published a key to 

 nymphs. 



Key to Species 



Nymphs 



I. Fourth segment of the antennae three-fourths as long as the third 



Carolina 

 Fourth segment of the antennae one-half as long as the third, .lacerata 



10 



