15 



animal life accumulate. Such are not at us ?ind fraf emus; 

 while spiniceps prefers swifter flowing waters like Quiver Creek 

 at Havana, or the upper Illinois River at Ottawa. 



In some species with which we have had but a limited 

 experience further study may show a wider range of normal 

 situations than that here assigned, but the preceding generali- 

 zations should have a value to the student and collector, and 

 may serve as a basis for a more exact account in future. 



The Illinois waters which afford the widest range of situa- 

 tions and are most prolific in variety of dragon-fly nymphs are 

 the small lakes of Lake county. Their shores are sometimes 

 exposed, wave-washed, and rocky, and the life here found is 

 remarkably like that of swift running water. Again, they are 

 broad and marshy, and afford a home for SijmpettunL Out 

 from shore we may find shallow waters with mats of aquatic 

 vegetation, bare sandy surfaces, or, at great depths, a bottom 

 of soft mud. As to numerical abundance I have seen nothing 

 in Illinois that can compare with the multitudes of dragon-flies 

 that issue in favorable seasons from the broad shallow lakes 

 along the Illinois River. 



ODONATA OF THE VARIOUS WATERS IN ILLINOIS. 



Taking the subject from a different point of view, we may 

 briefly summarize the odonate life of the Illinois waters as fol- 

 lows. 



In the larger rivers, down to the size of the Mackinaw, in 

 places where the water flows with considerable current over a 

 rocky bottom, Diastatomma may be looked for ; where mud 

 or sand bottom and quieter waters prevail, Ejjicorfhi/iff and 

 some species of Go nip hies may be found. Other species of 

 Gompkus occur in the bare muddy or sandy bottoms of the 

 sloughs and bottom-land lakes. In tree-shaded waters, where 

 driftwood and branches have gathered, or along muddy margins, 

 especially amongst exposed roots, the lower yEschnidw may be 

 looked for. In bottom-land lakes where vegetation is abundant, 

 one may find Anax, Agrionidce, Mesofhemis, Celithenus, Tramea, 



