578 W. AL. Fontaine—" Great Conglomerate’ on New River. 
ity of Lewisburg, and west of that town, to a bed of four feet 
in thickness. Still more developed are these coals in Mont- 
gomery County, where we have two beds, the lower 2-34 ft., 
and the upper 6-9 feet thick ; much of the latter being slate. 
The strata of this formation in Pennsylvania thin out rapidly 
to the northwest, just like the Conglomerate, according to 
Rogers. A line drawn in that direction, from near Western- 
port, indicates the direction of diminution. 
The next formation beneath, viz: the Catskill, will be found 
to change in a manner precisely similar to the above-mentioned 
deposits, but in degree even more striking. The following 
are the measurements of Wm. B. Rogers for West Virginia 
On the Potomac, near Westernport, he finds it 200 feet thick. 
In this part of the State a thin seam of coal presents itself, but 
often thins out and is lost. To the southwest, near Lewisburg, 
it is 800 feet thick, with the coal much more developed, attain- 
ing in one place the dimensions of nearly four feet. 
This formation to the northeast thickens much more rapidly, 
being, according to Dana, 2,000 to 3,000 feet in the Catskill 
Mountains.* To the northwest from the Potomac, it rapidly 
thins out. About six miles east of the White Sulphur Springs 
the cuttings for the west approach of Lewis Tunnel disclose a 
very impure bed of coal, about 12 inches thick, which at the 
opposite end of the tunnel has degenerated into a black bitu- 
minous shale. It is uncertain whether this bed occurs in the 
Chemung or Catskill. If in the former, it must be near the 
inclined and differ in character from those containing the coal. 
The latter also dip less steeply, and are apparently unconform- 
able with those lying more to the wes e 
he slates accompanying this small coal seam contain many 
beautifully preserved Devonian plants, which confirm the sup- 
position of the Catskill age of the strata. Among the plants 
here preserved are several species of Lepidodendron. Cyclopteris 
and others consider that the 
agrees better with the expansion of the coal to the S. W. 
