CLASSIFIED KEY TO THE INDEX. 101 
Page 
Pennsylvania 139 
Petrology 139 
California 139 
Canada 140 
Colorado 140 
Connecticut 140 
District of Columbia 140 
Georgia 140 
Idaho 140 
Iowa 140 
Maine 140 
Maryland 140 
Massachusetts 140 
Mexico 140 
Minnesota 140 
Montana 140 
New Hampshire 140 
New Jersey 140 
New York * 140 
Oregon 140 
Pennsylvania 1 40 
Vermont 140 
Washington 140 
Wyoming 140 
General 1-10 
Rocks described 140 
Physiographic geology 141 
Alaska Ill 
Appalachian region 141 
Atlantic coast region 141 
Canada 141 
Great Basin region 141 
Great Lakes region 141 
Great Plains region 141 
Mexico 141 
Mississippi Valley region 141 
New England and New York 141 
Pacific coast region 142 
Rocky Mountain region 142 
Southwestern region 1 42 
West Indies 1 42 
General 142 
Pleistocene 142 
Appalachian region 142 
Atlantic coast region 142 
Canada 142 
Great Basin region 1 42 
Mississippi Valley region * 1 42 
New England and New York 142 
Pacific coast region 142 
Rocky Mountain region 142 
Southwestern region 142 
West Indies 142 
