9 6 
The Ohio Naturalist. 
[Vol. X, No. 5, 
the dugway. At the south end of the dugway, or highway cut, 
it appears at the same level as where last seen on the west side 
near the railroad switch below Howenstein a few hundred yards. 
It may be noted in passing that the Upper Mercer coal 
thickens here to about 3 feet and a mine has been opened in it 
a quarter of a mile below Howenstein. 
The overlying limestone is also removed. This is the only 
mine met with in the territory covered opened in this coal; it 
nowhere else was found reaching this thickness. 
Near the north end of the highway cut the Upper Mercer 
limestone is well exposed beside the roadway. It occurs in two 
layers, the lower layer being very tough, bluish gray and 23 inches 
thick. The upper layer is brownish, coarser grained, contains 
considerable iron ore, and is 10 inches thick. The two layers 
thicken and thin at the expense of each other. No coal is found 
under it. 
At this outcrop a ravine trenches the hillside, and in this 
ravine two or three rods above the roadway another stratum of 
limestone is found at 22 feet 7 inches above the Upper Mercer 
limestone, and 15 inches thick. It is blue-black, very tough, 
and in one layer. It can be seen all along the bank above the 
roadway, but concretionary rather than as a continuous stratum. 
Coaly shale and fire clay underlie it. Northeast of the creek 
bridge at Howenstein about 200 yards and beside the hill road it 
may be seen in the run bed for several rods where it occurs in 
a definite bed showing decided undulation. This stratum is not 
the Putnam Hill limestone as might be thought. It is too near 
the Upper Mercer, and too far below the Lower Kittaning Coal, 
besides the Putnam Hill is present in the section at its proper 
horizon. It is clearly a new element not before recognized. 
Again, it is not merely a local development but is found nearly 
to the state-line as will appear in descriptions to follow. 
Having to deal with it repeatedly the writer names it the 
Howenstein limestone. At the south end of the highway cut and 
near the bridge the Howenstein limestone lies at 991 feet above 
sea, and 21 feet above rail at Howenstein depot. From this 
elevation the Upper Mercer is seen to lie at about 967 above, 
and the Lower Mercer at about 939. 
In the hill-side ravine spoken of above and sixty feet above 
the Howenstein limestone a fourth limestone occurs at 10.51 
feet above sea. This is undoubtedly the Putnam Hill which is 
here 2 feet, 8 inches thick and resting upon a bed of coal. Being 
only partially exposed the thickness was not obtained. Two 
miles up the Nimishillen this coal lies in two benches and is 4 
feet thick capped by the same limestone. As seen in the above 
ravine this limestone is rather a dark gray, weathering to a gray 
or a yellow-gray. It is very tough and lies in one layer. Crinoid 
