4 Cincinnati Society of Natural History. 



shales, interbedded with thin sandstone bands, which are 

 more frequent toward the bottom. The thickness of the total 

 section, identified by Prouty as Clinton, is about 550 feet, and 

 of this the upper fossiliferous section, containing Calymene 

 clintoni, occupies a thickness of about 100 feet. 



Overlying the Clinton section of Prouty, is a series of 

 strata about 300 feet thick, in which limestones are frequent, 

 although interbedded with more or less argillaceous shale. 

 This limestone section has been identified by Prouty as Roch- 

 ester. In the lower part of this series, sometimes 30 feet 

 thick, although usually less, the fauna containing Dalmanitcs 

 limulurus and H omolanotus is found. 



Between the Clinton argillaceous shales and the Rochester 

 section with its numerous limestone layers, there is a sand- 

 stone, thicker eastward, thinner westward, in the top portion 

 of which a ferruginous layer is present. 



It is significant in this connection to note that the fossilif- 

 erous block containing the fauna listed above from Martins, 

 in Lewis county, Kentucky, was distinctly sandy, and that a 

 considerable part of the West Union section at this locality 

 is rather coarse-grained and cross-bedded. It seems possible 

 therefore, to correllate the Crab Orchard clay section of Lewis 

 county, Kentucky, consisting of that part, 100 feet thick, 

 which overlies the Dayton limestone, with the much thicker 

 clay section of Maryland, identified by Prouty as Clinton. In 

 this case, the West Union bed of northern Kentucky may be 

 regarded as approximately equivalent to the lower pait of the 

 Rochester section, as identified by Prouty. 



In the Maryland section, a ferruginous sandstone occurs in 

 two beds, varying from several inches to six feet in distance 

 apart, at an elevation varying from 120 to 160 feet above the 

 base of the argillaceous section there identified as Clinton. 

 It is not known whether anything corresponding to this lower 

 ferruginous horizon occurs 'In Kentucky. It may be of inter- 

 est, however, to note in this connection, that the iron ore of 

 Bath countv, Kentucky, traces of which extend into Fleming: 



