136 
HUGHES : INGLEBOROUGH. 
There was no muddy bottom yet for shells to live on, and corals 
were scoured off the exposed bare rock surface. Only a few fish 
swam over and left their remains entombed. In one of these 
hollows I found Lophodus levissimus L.Ag. and Copodus cornutus 
L.Ag. 
It is interesting to note that these are closely akin to well- 
known Devonian forms, if not identical species. 
We ask what w^as going on over the surrounding district 
when this sea-plain was being formed here, and how far does the 
sea-plain extend? We soon find some evidence bearing on this 
point as we follow it to the north and west. Instead of resting 
on a smoothly undulating surface of bare rock, the Mountain 
Limestone has at its base enormous banks of gravel and sand 
now deeply stained red. 
* Along the valley of the Lune, by Kirkb}^ Lonsdale, Barbon, 
Sedbergh, and Tebay, it lies in a manner suggestive of a long 
valley with tributaries coinciding in direction with the present 
drainage system, but it does not resemble the gravel of river 
terraces. At the mouth of Ullswater high hills are wholly com- 
posed of it, and it plunges under the Carboniferous rocks on the 
east. Here it seems probable, from the form, the composition, 
and arrangement of the material, that the gravel carried down 
the steep valleys out of the heart of the Lake Mountains was, 
some of it perhaps, distributed along the shore, but was mostly 
swept into the seaward depths of the submerged valleys. The 
material seems always to be derived from the neighbouring rocks. 
In these thick masses of sediment no fossils have been found, 
except derivative fossils in the fragments of older rocks. 
Follow the base of the Carboniferous across the sea to the 
Isle of Man and to North Wales, and we find evidence of similar 
conditions having prevailed there. 
But if we travel on into South Wales we get beyond the 
sea-plain and its marginal valleys, and there find widespread 
sands, alwa^'s with white quartz pebbles, underl3^ing the Mountain 
Limestone and passing uncomformably across the Old Red of 
Herefordshire and the Silurian and Bala of Carmarthenshire. 
