of the great formation of Warwickshire. To the north and to the south of this barrier the Permian formation exists under two distinct phases or types of character ; and the occurrence of such a dividing ridge as I have indicated seems to offer the most satisfactory explanation of these differences in composition and arrangement.
Fig. 3. — Sketch Map of part of Lancashire, Cheshire, and Shropshire, showing the position of the concealed ridge of Lower Carboniferous Rock, or anticlinal axis, and of the Coal-measures to the north and south of the axis. By Edward Hull, F.R.S.
Coal-measures at the surface.
Permian Beds.
Triassic Beds overlying Coal-measures.
Triassic Beds resting on strata older than the productive Coal-measures.
EXPLANATION OF MAP.
This Map is intended to show the position of the existing Coal-
