316 CJalAIIl IFS, Wes KIO VGES 
of the section; in the southern, at the very bottom. As to the 
exact horizons of their occurrence the literature usually gave 
small clew. With most of the forms no comparison-was possi- 
ble, for the facies of the two faunas were of very different types. 
After an elapse of 30 years the question of the geological age 
of the various beds presented itself as formidably as when first 
these rocks were brought into notice. 
Of late years a number of deep wells have been drilled along 
the upper Mississippi River. These have enabled various geolog- 
ical sections exposed at points far removed from one another to 
be connected with a degree of confidence never before attained. _ 
In the Louisiana-Burlington cross-section, wells at Hannibal, La 
Grange, Keokuk, Burlington and other points have disclosed 
important features. These purely stratigraphical features are of 
particular interest at the present time because of their bearing 
upon the lack of geological integrity of the typical Kinderhook. 
On all of the problems mentioned, the data derived from the 
deep-well sections have an important bearing. Furthermore, it 
is pointed out just along what lines critical evidence is to be 
sought. 
A few years ago the geological sections at the type locali- 
ties of the several parts making up the Mississippian series of 
the Carboniferous, were personally studied in order to find out 
from first hands just what each really meant.t. Among these 
sections were those found in the vicinity of Kinderhook, Illinois, 
which were the basis of what had been long considered the 
lowermost member of the Carboniferous system, and had been 
widely known as the Kinderhook formation. Hannibal and 
Louisiana, Missouri, which are not far away, exhibited the same 
rocks even to better advantage, and therefore were regarded in 
all respects as essentially typical. 
As is well known, the typical Kinderhook has been regarded 
as consisting of three members: A basal Louisiana limestone, a 
median Hannibal shale, and a capping Chouteau limestone. 
‘Principal Mississippian Section; Bull. Geol. Soc. America, Vol. III, pp. 
283-300, 1892. 
