188 THE JOURNAL OF GEOLOGY. 
east of the farm line, Heliolites sub-tubulatus, and Halysites 
catenulatus. 
REMARKS ON SOME FORMATIONS ABOVE THE CLINTON. 
Observations by the Kentucky Survey.—The Magara shale 
seems to become thinner southward and westward in Kentucky, 
as far as can be determined from the statements: that it is 100 
feet thick in Lewis, Fleming, and Bath counties, 35 feet in 
Marion and Nelson, and 15 feet in Oldham, being sometimes 
entirely absent in the last county. It varies greatly in thickness. 
It is not mentioned from the most southern counties, but this 
may be partly owing to the difficulty in discriminating between 
the Niagara and the Crab Orchard shales in that region. 
The heavy beds of the Niagara are seen in Pickaway county, 
Ohio, and extended thence as far as Highland county of that 
state. In Kentucky, judging from residuary fragments left on 
the bedded rocks, the eastern line of outcrop once extended 
from Bracken county to Nelson and part of Washington 
counties. Continuing in the same southwesterly direction it 
passed into western Tennessee. West of the line thus located, . 
the heavy beds seem to have covered all the areas within the 
present regions of suitable outcrops in the states of Ohio, 
Indiana, Kentucky, and Tennessee. The beds therefore do not 
occur between Adams county, Ohio, and Washington county, 
Kentucky, the eastern and southern range of counties. 
The Oriskany, on the contrary, occurs only in these counties, 
from which the heavy Niagara beds are absent, that is in the 
counties from Lincoln to Bath. It usually is a single layer 12 to 
- 18 inches thick, but in Bath is three feet thick. It usually contains 
fish remains, which are often much rolled and rounded. 
The Corniferous occurs west of a line which lies so much 
farther east than the line of outcrop described for the heavy 
beds of the Niagara, that it practically occurs at all suitable 
exposures in Ohio, Indiana, and Kentucky, and is absent only in 
the extreme east, in Adams and Lewis counties, the Ohio river 
counties of Ohio and Kentucky. 
