293 
Coal seams have been wrought in the lower members of the 
series., var^dng very much in thickness. In the valley of the 
Aire, at Morton Banks and Thwaites, beds of coal are, or 
have been worked, which have a face of 4 feet 6 inches to 
6 feet thick. Coals, not so thick, have also been got from 
the same horizon in the valleys west of Halifax, and are found 
generally distributed over the lowest bed of Grit farther 
south. These are, in all probability, the equivalent of the 
Follifoot Coal Grits. The peculiar fossiliferous beds of the 
Cayton Gill series seem to have also their representatives in 
the southern district. In Luddenden Yalley, and on TVads- 
worth Moor, two beds of dark- coloured shale occur, which 
contain numerous specimens of the genera Goniatites and 
Avicula-pecten. The lower bed also encloses many nodides of 
limestone which, when broken, are found to be full of similar 
fossils and also Posidonia, Orthoceras, Nautilus and Modiola. 
Remains of fish were also found, of the genera Acrolepis, 
Acanthodes, and probably the teeth of Cladodus and Orodus, 
in making an aqua-conduit through the Thii'd Grits under 
"Wadsworth Moor. In other localities, at Warcock Hill and 
Pule Hill near Mossley, similar beds of shale are found, with 
fossil Molluscs. The Shales and Flagstones, with worm- 
tracks, appear to be very persistent beds ; and southwards 
may be seen, in many sections, to the west of Halifax, and in 
a fine section exposed in the bed in the stream in Ramsden 
Clough, near Holmfirth. In the latter the whole series of 
the Third Grits are exposed, resting on the Kinderscout Grit 
in the bottom of the valley. 
The Uppermost Grit usually forms a very decided 
feature in the landscape where it occurs. It is a massive, 
well-jointed, thick Sandstone, and extends for considerable 
distances in tabular, wall-like escarpments. In several 
localities it is a decidedly red colour, like its equivalent at 
Plumpton and 13rimham, and shows a tendency to weather 
