98 Cituinnati Society of Natural History. 



opinion expressed by Prof. Hall in 1842.* This report has 

 been quite extensively quoted, and it has been erroneously 

 considered to represent the views of the majority of the Cin- 

 cinnati geologists. It was criticised by Mr. U. P. James in 

 i'^79,t who, after giving the evidence adduced in favor of re- 

 ferring the rocks to the Hudson River and the Utica vSlate, 

 says that if the name " Cincinnati " be dropped, "it would seem 

 more approi)riate to take the Trenton Group, not Utica Slate, 

 nor Hudson River; the proportion of Trenton fossils in the 

 Cincinnati being more than tico to o)ie of the Utica Slate or 

 Hudson River." He was not, however, in favor of using Tren-" 

 ton, but of retaining the term Cincinnati, basing his argument 

 on the fact that only about one hundred out of the five hun- 

 dred species known from the Cincinnati Rocks, are identical 

 with species from either the Trenton, Utica or Hudson rocks 

 of New York ; and out of the one hundred, sixty-five are con- 

 fined to the Trenton, eighteen to the Utica and Hudson, and 

 the remainder are common to all three groups. 



In 1.S82 Mr. W. M. Linney.t of the Kentucky (leological 

 Survey, said lliat llie building stone (piarried at Point Pleasant, 

 Ohio, was doubtless the same as the gray limestone forming 

 the u])per part of the Trenton of New York. 



In 1882 Prof. Edw. Orton|| changed his reference of the Point 

 Pleasant Beds from the Cincinnati Group to the Trenton, thus 

 following Miller. The reference was made from the fact that 

 the Utica Shale was found to be three hundred feet thick at 

 Findlay, Ohio, and contained the characteristic fossil, Lcpto- 

 bolus It'pis; and this shale having disajipeared from the lower 

 ])art of the State, the Hudson rc^cks must rest directly uixni 

 the Trenton (iroup, which thus became exposed at Point 

 Pleasant. But this fact does not agree with the statement 

 made on page yyo of the same volume, that the Hudson River 



'-It is noteworthy that of the meiiihers of the coiuiiiittee reporting thus, two 

 of the five, who have since written npon the subject, have returnnl to the use of 

 the term "Cincinnati Group;" and this, too, within a year after the adoption 

 of the report. These two are A G. Wetherby and E. O. I'lrich. Messrs. MiUer, 

 Dyer and Mickleborouxh stiU adhere to Hudson River and I'tica Slate. As far as 

 known to the writer, the other five have not published any papers dealing with the 

 subject. 



fThe I'aleontologist, No. 4, pages 27-2S, 



JNotes on rocks of Central Kentucky, 1S82, page 6. 



IIGeol. Sur. of Ohio, vol 6, 1888, page 5. 



