Contents 



* 



PAGE 



Introduction xiii 



The Topography and Hydrography of Illinois xvii 



The Northwestern Unglaciated Area xviii 



The Areas of Iowan and Illinoisan Drift xix 



The Area of the Wisconsin Drift xxi 



The Unglaciated Southern Area xxii 



The River Systems xxiii 



Rock River System xxiii 



Rock River xxiv 



Pecatonica River xxvii 



Kishwaukee River xxvii 



Green River xxviii 



The Northwestern Area xxix 



Galena River xxx 



Apple River xxx 



Plum River xxxi 



The Mississippi Bluff Drainage xxxi 



Edwards River xxxi 



Pope Creek . . xxxii 



Henderson River . . xxxii 



Bear Creek xxxii 



Bay Creek xxxii 



Cahokia River xxxiii 



Illinois River System xxxiii 



Des Plaines River xxxiv 



Kankakee River xxxvi 



Iroquois River xxxviii 



Illinois River xxxviii 



Fox River xlvii 



Vermilion River xlix 



Mackinaw River 1 



Spoon River li 



Sangamon River lii 



Salt Creek liii 



Crooked Creek '. liii 



Apple Creek liv 



Macoupin Creek lv 



Kaskaskia River System lv 



Kaskaskia River lvi 



Shoal Creek lvii 



Silver Creek lviii 



Big Muddy River System lix 



*For species whose page numbers are preceded by a star (*) there are distribution maps 

 in the atlas accompanying this report. 



