THE CINCINNATI GROUP 45 



as to be entirely absent along the Mississippi in Missouri and 

 adjacent Illinois, in the Wells creek basin in northern Tennes- 

 see, and along the Tennessee river in southern Tennessee. The 

 Richmond also appears to become thinner west of the northern 

 half of the Cincinnati anticline. It becomes thinner also south- 

 ward along the flanks of the anticline. In some parts of Ten- 

 nessee it is entirely absent along the western flank of the anticline. 

 West of the southern half of the anticline, in Tennessee, the 

 thickness of the Richmond appears to vary irregularly. It has 

 not been detected in the Wells creek basin. A thicker clay 

 section than usual is seen west of Riverside. Both the lime- 

 stone and clay are thicker at Clifton than at most points nearer 

 the anticline. In the southern part of Hardin county, the Rich- 

 mond thins out to a few inches. If the identification of the 

 Saltillo limestone as lower Utica, and of the overlying limestone 

 at Clifton as the Warren bed, is correct, a very considerable inter- 

 val of erosion occurred during the middle of the Cincinnati age 



in western Tennessee. 



Aug. F. Foerste. 



