HUGHES : INGLEBOROUGH. 
47 
not identical in any two sections under Ingleborough, and, 
though showing points of Uthological and palaeontological 
similarity \^dth many of the sections at the same horizon 
further north, nowhere exactly represented in them. 
It may be useful, therefore, to ask what we might, from 
analogy, have expected to find here before we examine in detail 
what we do see. 
I give two sections, one of which (Plate VI.) shows an 
almost unbroken succession from the Bala Beds to the bottom of 
the Coniston Flags, and the other (Fig. 1) illustrates the way 
in which we generally find these easily crushed and faulted beds 
cut up and repeated, where they come out from under the 
Carboniferous Fells north of Ingleborough. When such beds 
are highly inclined, it is almost impossible to detect sharp 
plications and displacements, and we must always entertain the 
idea that the beds we miss may be nipped out by faults. 
The first section to which I refer (Plate VI.) is the most 
complete that I know of in the lower beds of the Silurian and 
the upper beds of the Bala series of our district. A detailed 
description of this section, with full lists of the fossils which 
occur at the various horizons, is given by Messrs. Marr and 
Nicholson in their valuable paper on the Stockdale Shales.* 
This section gives a sample of the material which was being 
laid dowm on the north side of Ingleborough while the Austwick 
sediments, which we have been describing, were being spread 
over the south side. We have found an immense thickness 
of felspathic slates with subordinate grit in Chapel-le-dale, and 
inferred that there were more of them exposed to denudation 
when the lowest beds of the Silurian were being formed. So 
also in the northern section we see a still greater thickness of 
felspathic mud such as might be derived from the volcanic 
series. Moreover, each and all of the finer beds at the base 
of the Silurian are much thicker in the northern area. 
In the SpengiU section we have the Lower Coniston Flags 
passing down into hundreds of feet of Pale Slates. These are 
generally gray with red bands, and at one horizon yield a beauti- 
fully striped rock. The graptolites which have been found in 
*Q.J.G.S., vol. xliv., 1888, p. 654. 
