DEVONIAN AND MISSISSIPPIAN FAUNAS 27a 
the Rocky Mountain Basin. The Western Continental Province 
remained much as in Devonian time, faunally isolated to a great 
extent from the interior province. The Eastern Border Province was 
even more isolated, its faunal history, so far as known, having no 
points of contact with the interior. 
The more complete and differentiated faunal history of the Missis- 
sippian is that of the Mississippi Valley Basin which will be used as 
a standard of comparison for the other provinces or subprovinces 
considered. 
THE MISSISSIPPI VALLEY BASIN 
The Southern Kinderhook fauna.—When the Upper Devonian or 
New Albany black shale is well developed in southern Indiana and 
Illinois, the initial Kinderhook bed, the Rockford limestone, follows 
it with no stratigraphic break. In following the Kinderhook beds to 
the north, however, they are found to succeed, unconformably, forma- 
tions of much greater age. The same condition also probably holds 
in passing from Burlington, Ia., to the south, although the transition 
beds from the Devonian to the Kinderhook are not exposed in the 
Burlington section. An actual land barrier, the Kankakee axis of 
Schuchert, separated these northern and southern basins at the begin- 
ning of Kinderhook time, when each basin was occupied by its own 
distinctive and characteristic fauna. Before the close of the Kinder- 
hook this barrier was submerged and a common fauna occupied the 
entire Mississippi Valley Basin. 
The fauna of the Rockford limestone contains new elements which 
were unknown in the preceding Devonian faunas, associated with 
certain other forms which are clearly Devonian derivatives. The typi- 
cal expression of this more southern type of the Kinderhook fauna, 
however, is found in the Chouteau limestone of central and southern 
Missouri and Illinois, although there are several modifications of the 
fauna in the various more or less local formational units of the Kinder- 
hook of this region. Among other things the fauna contains numerous 
goniatites, some of which are notable forms and have no relationships 
with any of our known Devonian goniatites. Aganides rotatorius, 
from the Rockford goniatite bed of Indiana, is identical with a form 
in the basal Mississippian beds of Belgium and Ireland. Associated 
