viii LIFE OF THE PLEISTOCENE 



B. South of Jackson Park 55 



C. South of Calumet Lake 55 



D. Near Lemont 55 



E. Calumet-Sag Channel 56 



F. Scattered Records 60 



IV. Typical sections of Beaches 61 



A. Glenwood 61 



B. Calumet 62 



C. Toleston 62 



V. Previous Glaciations in the Chicago Region 64 



VI. Summary 65 



Chapter III. The Life of Glacial Lake Chicago and its Successors 



I. General Statement 68 



II. Waning of the Wisconsin Ice Sheet and Formation of Ponded Waters 68 



III. Glacial Lake Chicago 68 



A. The Glenwood Stage 69 



Life 69 



B. The Bowmanville Low Water Stage 69 



a. Life of Wilmette Bay 71 



b. Other Deposits belonging to this Stage 73 



c. Cause of Low Water Stage 74 



C. The Calumet Stage 77 



a. Life 78 



b. Supposed Evidences of Marine Life 79 



D. The Toleston Stage 79 



a. Comparison with Modern Embayments 80 



b. Mollusk Fauna of Braddock's Bay 81 



c. Life of the Toleston Stage 82 



i. Wilmette Bay 82 



ii. Toleston Deposits in or near the Outlet 84 



iii. Vertebrate Life 85 



E. The Sag Low Water Stage (Kirkfield Stage of Lake Algonquin) 86 



a. The North Shore Channel (Wilmette Bay) 87 



b. The Calumet-Sag Channel (Sag-Outlet) : 88 



c. The Desplaines Valley 89 



d. Windsor Park, South Chicago 90 



e. Evanston 90 



F. The Hammond Stage 90 



a. Wilmette Bay (North Shore Channel) 91 



b. Sag Outlet (Calumet-Sag Channel) 92 



c. Near Calumet Lake 93 



G. Low Water Stage. The Champlain Submergence 93 



H. The Englewood Stage 93 



a. Life of Wilmette Bay 94 



b. The Sag Outlet 94 



I. The Present Great Lakes 95 



a. List of Mollusca now Living in the Waters of the Ancient Lake 



Chicago Basin 96 



