58 Cincinnati Society of Natural History. 
character of the strata of the Cincinnati uplift as previously 
worked out by Prof. Orton* is not explained. 
In 1890 Prof. Joseph F. James studied the Point Pleasant 
beds and gave a detailed columnar section.** He reached the 
conclusion that the rocks in the river bank from West Cov- 
ington to Ludlow are identical with the Point Pleasant beds, 
in which conclusion he was correct; and that neither belongs 
to the Trenton, in which he was incorrect, as these strata are 
unquestionably of Trenton age. In 1897 Winchell and 
Ulrich, in their correlation of Silurian horizons,t referred to 
the West Covington river beds as belonging to the Trenton 
group. 
Il. Eden Shales — (Utica Group.) 
The earliest identification of Utica at Cincinnati was by 
Prof. James Hall in 1842 (see ante p. 53). The Committee‘on 
Geological Nomenclature of the Cincinnati Society of Natural 
History (see ante p. 55) also considered these strata, at least 
the lower part of them, as Utica. Later these strata seem to 
have given trouble. Ulrich in his paper on the correlation of 
the Lower Silurian Horizons} says: ‘‘Several feet of shales 
that are supposed to represent the portion of the section imme- 
diately below that mentioned in the preceding paragraph [the 
West Covington or Ludlow strata] are exposed under the 
bank of the river in the First Ward of Cincinnati.” In 
reality these shales overlie the Trenton rocks of West Cov- 
ington. This error has caused some of the fossils which 
properly belong in column XIb to be placed in column XIa§. 
In this same paper Ulrich|| identifies his ‘‘Beds XIb,” to 
which he gives a thickness of 225 feet, with the black shales 
300 feet thick, immediately overlying the Trenton in the 
Findlay wells, which he agreed with Prof. Orton in correlat- 
ing with the Utica shale of New York. ‘There can be no 
question as to the correctness of this identification. 
* Geol. Ohio, I, 1873, p. 412. 
** Jour. Cincinnati Soc. Nat. Hist., XIV, 1891, pp. 93-104. 
+ Geol. Minnesota, III. Part 11, 1897, p. xeviii. 
t American Geologist, I, 1888, p. 309. 
7 Amer. Geologist, I, 1888, pp. 183-190. See also p. 312. 
|| Ibid., p. 315. 
IO 
