CONNECTICUT GEOL. AND NAT. HIST. SURVEY 



[Bull. 



Abdomen lanceolate in outline, not abruptly but slowly narrowed to 

 the tip ; hind margins of the eyes viewed from above before the 

 middle of the head; labium of characteristic form as shown in 



Plate VII, Figs, i, S ; length full-grown, more than 21 mm 



LrBELLULiNi, p. 240 



Abdomen not lanceolate in outline, abruptly narrowed at the caudal 

 end ; hind margins of the eyes viewed from above, at, or behind 

 the middle of the head; labium not as shown in PI. vii, Figs, i, 



5 ; nymphs of small size not measuring over 21 mm 



Sympetrini, p. 261 



b LIbellula 



Fig. 40. Thoraces of representative Cordulinae (a), and Libellulinae (b), 

 showing differences in curvature of the mesopleural suture. 



4- 



Adults 



Front margins of the triangle of the front wings broken (PI. xii. 

 Fig. 2) Brachydiplacini, p. 259 



Front margins of the triangle of the front wings continuous 2 



Proximal side of the triangle of the hind wings distad of the 

 arculus ; anal loop not foot-like in the hind wings (PI. xi. 

 Fig. I ) Macromiini, p. 201 



Proximal side of the triangle of the hind wings in line with or 

 proximad of the arculus ; anal loop foot-like in the hind wings 3 



Hind wings 15 to 20 mm. wide at base (PI. xv, Nos. i, 2) ; dorsal 

 carina distinct on segments 3 to 8 of the abdomen ; proximal 

 and distal margins of the stigma not parallel Trameini, p. 288 



Hind wings less than 15 mm. wide at base; if approaching 15 mm. 

 in width, then either without a distinct carina on all the seg- 

 ments 3 to 8, or with the proximal and distal margins of stigma 

 parallel 4 



M2 with a decided bend at middle (PI. xv, Fig. 3) Libellulini, p. 240 



M2 without a decided bend at middle S 



Caudal margin of pronotum entire and without a long fringe of 

 hairs ; mesopleural suture as in Fig. 40, a ; colors usually metal- 

 lic blue or green Eucorduliini, p. 206 



Caudal margin of pronotum bilobed and with a long fringe of 

 hairs ; mesopleural suture as in Fig. 40, b ; colors not usually 

 metallic blue or green 6 



Sexes strongly dimorphic in wing color ; hind wings not over 20 

 mm. in length (PI. xin, Figs. 2, 4) Palpopleurini, p. 257 



Sexes not strongly dimorphic in wing color ; hind wings usually 

 more than 20 mm. in length (PI. xiv, Fig. 3) ...Sympetrini, p. 261 



