DRAGONFLIES OF DOUGLAS LAKE REGION. 47 



Xymplis. 



A. Middle legs closer together at the base than the fore ones; inner wiiit; oases strongly 

 divergent. 



Gomphoides 



AA. Middle legs as far apart as the fore ones. 



B. Inner wing eases stro.igly divergent. 



Ophiogoinphus 



BB Inner wing oases parade.. 



C. Third antennai joint flat, snhcylindrical or broadly oval; body broad 

 and Hat. 



Hageniiis 



CC . Third a.iteiina: joint suhojlindrioal, more than twioe as long as thick. 

 D. Dorsal hooks short but with acute spiny tips. 



Dromogomphiis 



DD. Dorsal hooks sometimes present, but obtusely pointed, 

 usually absent excepting a median tooth on the ninth segment. 

 Gomphus 



GENUS GOMPHOIDES SELYS. 



Gomphoides ohscurus (Rambur). — The nymphs of this species were 

 taken at the station on Maple River about two miles below the source. 

 They seem to prefer the swifter parts of the stream, clinging to and 

 craAvling over the vegetation and rocks. 



GENUS HAGENIUS SELYS. 



Hagenius hrevidylus Selys. PI. IX, Fig. F.; PI. X, Figs. B. D.— 

 Nymphs of this queerly designed species were taken many times during 

 the summer. They were found in ]\Iaple River, Bessey Creek and in 

 the beach pool near North Fishtail. The nymphs were taken from the 

 first layers of ooze along the bottom. No adults were taken. 



GENUS OPHWOUMPHUS SELYS. 



Ophiogomphus carohis Needham. — Nymphs of this species were 

 found only in Maple River. Like those of Gomphoirles ohscurus they 

 were found in the relatively swift water on submerged veg(>tation, logs 

 and rocks. N^o adults were taken. 



GENUS GOMPHUS LE.\C1I. 



Imayog. 

 A. Face entirely yellow. 



B . Tibia yellow externally; posterior abdominal segments not dilated. 



G. spictitus 



BB . Tibia black externally. 



C . Posterior emi of the abdomen dilated. 



G. vi'iitricosus 



CC. Posterior end ot the abiiomeii not diluted. 



G. ileitcri plus 



