TABLE OF EQUIVALENCY OF THE GEOLOGICAL FORMATIONS OF WISCONSIN, IOWA, AND MINNESOTA. 
MIDDLE AND WESTERN STATES, AND 
GREAT BRITAIN, 
WISCONSIN, IOWA, AND MINNESOTA. PENNSYLVANIA. STATE OF NEW YORK, 
CANADA, 
Coal-measures of Ohio. No. XIII. 
Coal-measures of Iowa? “ Michigan? No, XII. 
Conglomerates and ferruginous grits of Iowa R.? 
Upper Carboniferous Limestone. 
he a Fine-grained Sandstone of the Knobs. No, XI. 
No. X. Old Red Sandstone. 
No. IX. Portage and Chemung Group. 
Black bituminous shale of the Knobs, and Goniatite 
Limestone of Indiana No, VIII.? Genesee Slate. 
Upper coralline and shell-beds of Cedar Valley. No. VIII. Mamilton Group. 
“ Marcellus Slate. 
Shell-beds of the Falls of the Ohio. bs Corniferous ACE 
Lower Coralline beds of Cedar Valley? Coralline-beds “ . Onondaga Lim 
No. VII. Oriskany pape Dude and Schoharie grit. 
Limestone of Little Traverse Bay. Pentamerus and Delthyris Shaly Limestone. 
Mackinaw Limestone Onondaga, Salt Group, and Water Limestone. 
Geodiferous beds of Lake Michigan. 
Waukeshaw Limeston No. VI. Niagara Group. 
Coralline and esate beds of the Upper Mag- 
nesian Limestone, F. 3, c 
Oolitic Iron-ore of Ohio and Tennessee. No. V. Clinton Group. 
Place of supposed Red Sandstone of Lapham? Medina Sandstone of Canada, dina Sandstone. 
No. IV. eg Sandstone and Oneida Conglomerate, 
Lead-bearing beds of the Upper Magnesian Lime- 
stone, F, 3, B. 1slates in Canada — Lorraine shales of N. Y No. III, Utica Slate and Hudson R. Group. 
Bluish-green Limestone. 
Shell-bed F. 3, a. Blue Limest f Ohio in part No, II. in part. | Trenton and Black River Limestone. 
Bird’seye and Chazy Limestone. 
Upper White Saccharoid Sandstone, F. 2, ¢. 
Lower Magnesian Limestone, F. 2, a and », Siliecous and Calciferous Limestones. No. II. inpart. | Calciferous Sandrock. 
No. IL. Potsdam Sandstone. 
ured quartzose sandstone, F. 1, 
Red argillaceous and ferruginous sandstones, and | 
Shales of Lake Superior. | 
Upper Gray Sandstone, and _ 
Variegated Sandstones of Pictured Rocks, 
Coal-measures. 
Millstone grit. 
Upper Scare, or Yoredale Series. 
Lower Scar Limestone. 
Old Red Sandstone. 
Devonian System, in part. 
Ludow Rocks, including Aymestry Limestone. 
Wenlock Rocks. 
Middle part of Lower Silurian System, or Caradoc 
Sandstone and 
Llandeilo Flags of Murchison. 
