521 



h. Superior anal appendages blunt ; lateral profile as 



shown in Fig. 200 calverti. 



hh. Superior anal appendages acute ; lateral profile as 



shown in Fig. 201 cyatliigeruni. 



ff. Inferior anal appendages shorter than the superiors. 



g. Superior anal appendages with the apical tubercles pro- 

 jecting noticeably beyond the dorso-caudal angles when 



viewed from the side (Fig. 175) douhledayi. 



gg. Superior anal appendages with the apical tubercles not 

 projecting noticeably beyond the dorso-caudal angles 



when viewed from the side (Fig. 198) civile. 



aa. Dorsum of the second abdominal tergum w^holly black. 



b. Second antennal segment pale except the distal third, which is dark 

 brown or black. 



c. Dark stripe of the mesopleural suture paler in color than the 

 dorsal stripe covering the carina and often reduced to a mere 



line pollutum. 



cc. Dark stripe of the mesopleural suture not paler in color than 

 the dorsal stripe covering the carina and never reduced to a line 

 signatum. 



bb. Second antennal segment entirely dark brown or black. 



c. Front with the blue color extending dorsad to the median ocellus ; 

 postocular spots forming an equilateral triangle ; black stripe of 



the mesopleural suture indistinct or wanting traviaium. 



ec. Front with the blue or pale color not extending dorsad to the me- 

 dian ocellus, not dorsad of the antennal fossae ; postocular spots 

 forming a wedge-shaped figure; black stripe of the mesopleural 

 suture distinct, never wanting, 

 d. Superior anal appendages bifurcate. 



e. Dorsal arm of the superior appendages shortest ; arms not 



widely divaricate (Figs. 203, 210) exsulans. 



ee. Dorsal arm of the superior appendages as long as the ventral ; 



arms widely divaricate (Figs. 202, 209) antennatum. 



dd. Superior anal appendages not bifurcate (Figs. 190, 197) 



divagans. 



Enallagma antennatum (Say) 



Nymph. — Color, brow^n or greenish. 



Head about half as long as wide, the caudo-lateral angles project- 

 ing strongly caudad and thickly studded with setae; second antennal 

 segment slightly shorter than the first, the first two segments dark and 

 pilose; labium with three mental setae, four or five lateral ones, and 



