CORRELATION WITH KENTUCKY 579 



the top of the Bigby is a finely granular, siliceous rock, which also sug- 

 gests the Brannon bed. 



Writers upon the Trenton of these States seem to be in general agree- 

 ment that the Hermitage of Tennessee is equivalent to the Logana of 

 Kentucky, this opinion being based almost entirely upon the fact that 

 Dalmanellse are exceedingly abundant in both. This would be a harm- 

 less enough correlation if it were not followed by the logical deduction 

 that the Jessamine is not represented in central Tennessee. 



The lower strata at Nashville contain almost nothing except the Dal- 

 manella to which Bassler has given the name fertilis. In the vicinity of 

 Columbia, Tennessee, Hayes and Ulrich list a small fauna in which 

 Prasopora patera is said to be abundant and P. simulatrix common. 

 Miller states that in Kentucky he separates the Jessamine from the 

 Logana because only in the former do Prasopora simulatrix and Dal- 

 manella occur together. In the Jessamine, Damanellse are equally as 

 abundant as in the Logana, and it is only at the base of the Benson that 

 they disappear. Like the Capitol limestone above it, only to a lesser 

 degree, the Hermitage is irregularly bedded, and in places the strata are. 

 nothing more than masses of wave-piled shells. How long a time is 

 represented by the Hermitage and Bigby together can not be determined 

 from the formations in the area which I studied, but I should judge that 

 deposition began only in the later part of Jessamine time. The particu- 

 lar fossils characteristic of the Benson have not been found in the Bigby, 

 but that is hardly surprising, considering the conditions under which the 

 latter appears to have been deposited. Of the various fossils listed from 

 the Bigby of Tennessee by Hayes and Ulrich, Constellaria teres appears 

 in Kentucky first in the Woodburn, while Hebertella frankfortensis, 

 Bhynchotrema increhescens, and Cyrtolites retrorsus are found in the 

 Jessamine and higher strata. 



The Cynthiana, Catheys, and Leipers 



If now attention be turned to the upper part of the section, more diffi- 

 culties will be encountered. They are, however, difficulties which we have 

 fabricated for ourselves by our habits of thinking rather than any pre- 

 sented by the strata and faunas themselves. Dr. Ulrich holds that the 

 Catheys and Cynthiana are to be classed with the Trenton, while Pro- 

 fessor Miller would unite them with the Cincinnatian. All who have 

 written on the subject agree that the "Utica" and Eden are absent from 

 Tennessee, and that the Leipers is of Maysville age. 



In such regions as the vicinity of Nashville and the southwestern part 



