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platy beds on top of the Main Limestone. Swallow holes occur 
here and there above the outcrop of the Main Limestone, some- 
times higher than we should expect them, because of the great 
mass of talus that has crumbled down upon it. The shale 
between the Millstone Grit and the IMain Limestone is exposed 
in a swallow hole at the south end of the hill. 
The top of Ingleborough is not quite level, but rises slightly 
to the north-west, swelling up a little about the centre. This 
is partly due to a slight dip to the south-east and also to the 
manner of denudation of the softer strata which occur on the 
summit. 
The highest beds seen consist of flaggy grit and sandstone, 
but there is no clear section through them, the surface being 
everywhere covered with a mass of angular debris, apparently 
derived from the underlying rocks. I once dug through this to 
the depth of between three and four feet and foand what ap- 
peared to be the disintegrated surface of the rock in place. It 
was not only broken up along joints into angular fragments, 
but often decomposed into a coarse sand. In the finer beds 
I have found two species of lameUibranch, Anthracosia sp. and 
Sanguinolites plicatus (Port!.), and in the coarser beds fragments 
of Calamites and Stigmaria. These flags rest upon a coarse grit 
full of pebbles of white quartz, about the size and form of horse 
beans and marbles. There are occasionally small flat pieces of 
ironstone to three inches in diameter in the grit, but it is not 
clear whether they are concretionary or rolled fragments. The 
coarse grit passes down into a finer grained rock with no pebbles, 
but false bedded sandstones and grit are apt to change within 
very short distances, a very good example of which may be seen 
in the sandstone of the Yoredale Series just belov/, where one 
of the beds of sandstone is chamfered off by cross current action, 
so that the end of a ten foot bed stands at about the steepest 
slope that sand would rest at under water. It is thus a question 
where we should draw the base of the Millstone Grit, but in a 
continuous series like this it is an arbitrary division and of 
little importance, and it is most improbable that we can establish 
an exactly synchronous base throughout the district ; aU we can 
