KENTUCKY GEOLOGICAL SURVEY. 19 



Kentucky, as the uppei part of the same beds. Linney referred 

 the Point Pleasant beds to the Trenton. In the writer's paper 

 on "The Geology of Cincinnati" 9 the Point Pleasant beds were 

 placed in the Trenton, as also were the exposures at Covington. 

 The study of the collections made during the past summer has 

 convinced the writer that the fauna is very much more closely re- 

 lated to the Cincinnatian fauna than to that of the Mohawk- 

 ian. In the rapid alternations of shale and limestone, also, the 

 Winchester has the characteristic Cincinnatian aspect. . Al- 

 together, the formation seems to have been deposited under 

 conditions much more like the Cincinnatian than the Mohawk- 

 ian. Apparently, though more fieldwork is necessary to estab- 

 lish this, there is a marked unconformity between the Lexington 

 and the Winchester, much greater than that between the Win- 

 chester and the Eden. 



MOHAWKIAN. The term Trenton has been widely used in 

 the geological literature of this country to designate any forma- 

 tion supposed to be the equivalent of the Trenton of the New 

 York system. This has produced confusion. So Clark and 

 Schuchert 10 have proposed that the term Trenton be restricted 

 to the formation typically displayed on West Canada Creek at 

 Trenton Falls, New York, and that the term Mohawklan in- 

 clude the Trenton, the underlying Black river, and the Lowville 

 or Birdseye. 



Stratigraphy. 



The middle and upper Ordovician as developed in the region 

 of the Cincinnati uplift is exceedingly fossiliferous. All classes 

 of invertebrates, capable of preservation as fossils, are repre- 

 sented. The fauna was marine. No undoubted specimens of 

 fish remains have vet been found in this region. Bryozoa and 



"Journal, of the Cincinnati Society of Natural History, 20, p. 60, 1902. 

 10 Science (n. s.) 10, p. 875, 1899. 



