THE KIMMSWICK AND PLATTIN LIMESTONES 
179 
and Bassler prefer to use the terms Kimmswick and Plattin in 
a more restricted sense. A modification of a part of one of their 
tables is presented here in the following form: 
KENTUCKY 
SOUTHEASTERN 
MISSOURI 
NORTHEASTERN 
MISSOURI 
MINNESOTA AND 
NORTHERN IOWA 
Branson’s geol. 
OF MISSOURI 
McCune 
Stewartville 
Kimmswick 
Curdsville 
Prosser 
Prosser 
Kimmswick 
Clay shale 
Auburn 
Decorah 
Plattin 
Tyrone 
Plattin 
Bryant 
Platteville 
Oregon 
Folley 
The preceding table suggests that in Champlainian times north- 
eastern Missouri formed part of the northern Mississippi valley 
province, including Minnesota, Wisconsin, and northern Iowa. 
While considerable lithological differences are noted in passing 
from northern Iowa across a long gap into northeastern Mis- 
souri, a considerable part of the northern fauna may be still 
recognized as far south as northeastern Missouri. It is not cer- 
tain, however, that the typical Kimmswick fauna of southeastern 
Missouri passes across the gap in northern Warren and southern 
Lincoln Counties into northeastern Missouri. This can be 
determined only after it has been ascertained definitely what 
are the characteristics of this fauna, not at Thebes but at 
Kimmswick, the type locality. Bassler lists only 4 species from 
the Kimmswick: Comar ocystites shumardi, C. ohconicus, Echinc- 
sphaerites aurantium, and Eurydictya calhounensis. None of 
these species is known at Kimmswick, and the first three are 
regarded as belonging beneath the lowest strata exposed in the 
Thebes section. 
If in Champlainian times there was an east and west barrier 
across the central part of Pike county in the area now traversed 
by the Cap au Gres fault, such a separation of northern and 
southern faunas might have been operative at various times and 
