BZ CHARLES S PROS SLL 
The shales at Orangeville are dark to bluish-gray, differing 
as a rule considerably in structure and color from the Sunbury 
shale. It is evident that the black shale overlying the Berea 
grit, reported by Dr. Orton from many wells in northern Ohio 
as the Berea shale, includes more than that shale, and corres- 
ponds to the Orangeville shale of Dr. White. Some geologists 
believe that the Orangeville shale, comprising all the rocks on 
the eastern line of the state included between the top of the 
Berea and the base of the Sharpsville sandstone, is the litho- 
logic unit which ought to be represented on the United States 
geologic maps of northern Ohio. This is the opinion of Profes- 
sor H. PP. Cushing and Dr. (George, i Girty, and isientitledito 
careful consideration, especially since Dr. Girty writes that the 
Orangeville shale, Sharpsville sandstone, and Meadville shale 
‘“maintain themselves across northern Ohio and appear in Medina 
county in fairly characteristic aspect.” * 
If the Orangeville shale be accepted as the lithologic unit for 
mapping in northern Ohio, then the Sunbury shale will become 
the lower member of the Orangeville formation for that part of 
the state. 
Note.—In an article entitled ‘The Classification of the Waverly series 
of Central Ohio,” published in the JOURNAL OF GEOLOGY, the writer referred 
to the revised classification of the New York rocks by Dr. John M. Clarke 
and Mr. Charles Schuchert.? 
It was intended to state, in the first place, that two principles of nomen- 
clature which had been given, had been imperfectly observed by many geolo- 
gists in their works on stratigraphical geology. In the second place it was 
intended to state that, on account of this more precise use of stratigraphic 
names, it had become necessary to revise even the classic nomenclature of the 
New York series of formations, in which case it was also found necessary to 
replace several o]d and well-known names by new terms. The reference to the 
revised New York classification was intended as a complimentary one, and 
as a precedent for similar revision of the classification of other states. These 
two ideas, however, were expressed in one sentence in a somewhat infelici- 
tous manner which has led to some misunderstanding regarding the real mean- 
ing, and therefore the above explanation is made. 
CHARLES S. PROSSER. 
COLUMBUS, OHIO, 
March, 1902. 
* Letter of February 28, 1902. 2Vol]. IX, 1891, p. 206. 
