NOTES ON MEDINAN, NIAGARAN, AND CHESTER 
FOSSILS 
AUG. F. FOERSTE 
A. The correlation of Ohio, Indiana, and Kentucky Medinan and Niagaran 
strata 37 
B. The fauna of the Whirlpool sandstone of Ontario 50 
C. Fossils from the base of the Manitoulin limestone at Credit Forks, Ontario. 58 
D. A lower Medinan fauna below the Brassfield limestone in Ohio 72 
E. The brachiopoda of the Brassfield limestone of Ohio 88 
F. The gasteropoda of the Brassfield formation of Ohio 94 
G. Niagaran fossils from Jeptha Knob, Kentucky 105 
H. Trilobites from the St. Clair limestone of Arkansas 109 
I. A new gasteropod from the Guelph formation of Ohio 115 
J. A Stigmarian root from the Chester formation of Illinois 116 
A. THE CORRELATION OF OHIO, INDIANA, AND KENTUCKY MEDINAN 
AND NIAGARAN STRATA 
In East-Central Kentucky the following Silurian strata, in 
descending order, may be discriminated. ^ 
fEstill clay 
Alger formation sWaco limestone 
[Lulbegrud clay 
Indian fields forma- /Oldham limestone 
tion. iPlum .creek clay 
Crab Orchard di- 
vision of Niagaran 
Medinan Brassfield formation Brassfield limestone 
The so-called Waco limestone is merely that part of the Alger 
formation in which a few limestone layers occur. In the type 
area one of the limestone layers is from 1 to 2 feet thick. The 
other limestone layers are less than 1 inch thick. Fossils occur 
both in the limestone and in the clay shale. Neither limestone 
nor fossils can be traced north of Indian Fields, Kentucky, and 
^ Foerste- A. F., The Silurian, Devonian and Irvine formations of east-central 
Kentucky: Kentucky Geol. Survey, Bull. 7, 1906, p. 27. 
37 
