URAGONFLIES OF DOUGLAS LAKE REGION. 43 



Agrion aequabile (Say). PI. IX, Fig. B.— Adults ami iiymj)h.s of tlii.s 

 species were taken on Bessey Creek, and at the station on Maple River, 

 about two miles down stream from the source. Although a number of 

 both adults and nymphs were taken in both situations the adults were 

 rather uncommon on Maple River. The nymphs in general were 

 found clinging to the vegetation in the stream, seeming to pref(>r the 

 swifter parts. 



Agrion maculaium Beauvois. PI. IX, Fig. 1). — This species was 

 taken in both the adult and nymph stages in the same situations as 

 Agrion aequabile. The adult with its handsome black or smoky wings 

 is easily distinguished when once seen, while the nymph with its sprawl- 

 ing legs is easily recognized. 



GENUS HETAERINA HAGEN. 



Hetaerina americana Fabricius. PI. IX, Fig. A. — None of the 

 nymphs of this beautiful dragonfly were collected but adults were taken 

 by Ur. Max M. Ellis at the station some distance down Maple River. 

 The brilliant red at the bases of the wings of the males and the i)ale 

 brown at the bases of the uangs of the females will distinguish this 

 species at once. 



FAMILY COENAGRIONIDAE. 



KEY TO THE SUBFAMILIES OF COENAGRIONIDAE. 



Imagos. 



A. Vein M3 arising from vein Mi and 2 nearer the arculus than the aodus. 



Subfamily Lestinae 



A.A. Vein \U arising from vein Mi and 2 nearer the nodus than the arculus. 



Subfamily Coenagrioninae 



Nymphs. 



A. Lateral labial lobes trifid at the distal end, movable hook of the labium bearing raptorial 

 setae. 



Subfamily Lestinae 



AA. Lateral labial lobes bifid at the distal end, movable hooks of the labium without raptorial 

 setae. 



Subfamily Coenagrioninae 



SUBFAMILY LESTINAE. 



A single genus, Testes, is known from the subfamily Lestinae at 

 Douglas Lake. Since the females of the genus are so ver}- much alike 

 no key has been made to distinguish them, the following k(\v being onl>- 

 for the determination of the males. Also no key has l)een made for the 

 determination of the nymphs as their great similarity makers itlentifica- 



