382 C. A, White on the Iowa Coal-measures, 
beds as far north as Marshall county. 
It will be seen then that these two members occupy a very 
limited area within the State, but the St. Louis limestone and 
Kinderhook beds—the upper and lower members of the group 
in Iowa—occupy a much larger area than any of the others. 
the Devonian rocks, and reaching from Muscatine nearly to 
Davenport. a3 
Almost all the coal of Iowa is found in the lower and middle 
Coal t i 
hes, the valleys are often found to have been ero 
‘Coal-measures, exposing the Subcarboniferous lime- 
h in this region is invariably the St. Louis division. 
: that prominent angle of the coal field in seas and 
_*ardin counties is found to rest directly upon the equivalent 
(Of the Kinderhook beds, the St. Louis limestone and all other 
