13 



idre, Hagenius, and the lower .^.sr A >^/rA/') inhabit driftwood and 

 submerged roots and brush. The second division comprises the 

 heavier nymphs of the Libellulidce, which usually sprawl upon 

 the bottom or climb over fallen rubbish ; and the third con- 

 sists of the remaining GompJnfJ(e, the Cordidegasfcridw, and, 

 to some extent, LiheUula and its relatives, which occupy the 

 mud or sand of the bottom. 



The species inhabiting submerged vegetation, constituting 

 the first group, are of course most abundant in the quiet waters 

 of slow streams, lakes, and ponds, where such growths have an 

 opportunity to develop freely. The large and active nymphs 

 of Trconea and PantaJa appear to prefer the more exposed 

 shores of large lakes and rivers. Mesotlietuis collocafa is 

 adapted for life in the high temperatures of water from the hot 

 springs of the west. The Agrionidw and Anax are common 

 everywhere in bodies of water with vegetation, from the small- 

 est pool to considerable lakes. The other y^schnidce climb on 

 dead sticks and driftwood where there is little vegetation and 

 food is not abundant, as in the bottom-land lakes and sloughs 

 of the larger streams with good current, or {Boijeria) in the 

 deeper holes along small streams, where projecting roots catch 

 the floating driftwood. Ha gen ins also lives amongst driftwood 

 and dead leaves in streams. The Calopferggidw thrive in little 

 rapid-flowing sandy rivulets like White Oak Run and Quiver 

 Creek at Havana. 



In the second group, those living on the bottom, depth and 

 current are important in determining the particular species 

 likely to be found. EpicorduUa likes the deeper waters, as of 

 the Illinois River itself or its deeper lakes, or the bottoms of 

 the small lakes of northeastern Illinois, finding there the 

 molluscan diet it enjoys. On the other hand Sgnipdruni and 

 Leucorh'niia inhabit marshes and reedy shores, as well as shal- 

 low weedy ponds and wet meadows. The " Pumpkin Patch '' 

 at Havana, the shores of Fourth Lake in northeastern Illinois, 

 and the swampy spots of the upland prairie, are situations of 

 this character. PachydAplax appears to like the deeper swamps 



