DEVONIAN AND MISSISSIPPIAN FAUNAS 275 
divisions, the Louisiana, Hannibal, and Chouteau, as has usually been 
done, does not express the proper relationships of the faunas. The 
Chouteau fauna, in some of its expressions, is without doubt as old as 
the Louisiana fauna, and it is as impracticable to make one continu- 
ous section to contain all of the Kinderhook formations, as it would 
be to make a standard Devonian section to include the formations of 
New York and Iowa. 
Early Mississippian jaunas oj the Appalachian Basin.—In the 
waters between the Cincinnati arch and the old Appalachian land in 
early Mississippian time, the faunal conditions were more like those 
of the southern Kinderhook province than the northern. In the Bed- 
ford shale of that basin a fauna occurs which is largely of Devonian 
derived species, and like the southern Kinderhook faunas these species 
have their relationships with Hamilton rather than with Upper 
Devonian forms. The succeeding formations in Ohio constitute the 
several members of the Waverly group with faunas showing more or 
less close relations with those of the southern Kinderhook. In the 
northern part of the basin, as in the Waverly beds of northwestern 
Pennsylvania, the presence of such forms as Paraphorhynchus' sug- 
gest relationships with the northern Kinderhook faunas of the Missis- 
sippi Valley, a relationship which might have been established by 
faunal migration from the West to the East by way of the Traverse 
Strait and Michigan. 
Post-Kinderhook faunas of the Mississippi Valley Basin.—With 
the submergence of the Kankakee Peninsula and the partial or com- 
plete submergence of the Ozark land, the source of the clastic sedi- 
ments in the immediate Mississippi Valley region was removed, and 
a great period of limestone formation was initiated which is best exem- 
plified in the Burlington and Keokuk formations. The fauna of this 
clear sea was in large part an outgrowth of the later Kinderhook 
faunas, and is best characterized by the wonderfully rich crinoidal 
element. 
The fauna of the formations which together constitute the Osage 
division of the Mississippian is in some respects unique. The great 
crinoidal element is in large part or wholly indigenous to this province, 
t Rhynchonella medialis and R. striata Simpson (Trans. Am. Phil. Soc., XV, 144), 
from Warren County, Pa., are members of this genus. 
