HUGHES : INGLEBOROUGH. 
]95 
What are the distinctive fossils of the God's Bridge black 
limestone ? Why is it black ? Is it derived from plants which 
grew on the adjoining land ? Or is the carbonaceous matter 
derived from seaweeds which must have grown on what would 
correspond to our laminarian zone, or is it, as some hold in 
the case of the Kimeridge Coal, of animal origin ? 
Next we notice that the quartz pebbles are far more numerous 
and occur throughout a greater thickness of limestone over the 
south-western part of the district, and that sometimes the 
quartz occurs in subangular fragments. If we were to collect 
thousands of them where weathered out, could we classify them 
according to the degree of translucency or crystalhsation, or 
anything that might help us to identify the quartz if we met 
with it in veins beyond the region now covered by Carboniferous 
rocks. 
The fragments of schists and sandstone also vary in size, 
manner of occurrence, colour of matrix, &c. Can we make 
out in each area the proportion of those derived from the im- 
mediately underlying rock to those derived from some way off, 
and can we, from what we have inferred as to the direction 
of the folds in the pre-Carboniferous rocks (see vol. xiv., 
p. 332 ; vol. XV., p. 358 ; and the consequent position of 
the outcrops, form some idea as to the drift of the agent 
which transported them ? In this connection let us observe 
the manner of occurrence of the corals in the basement con- 
glomerates. They must have grown on the large boulders 
w^edged in together wherever there w^as a small hollow to catch 
and hold them. But there were some strong currents now and 
then wMch tore them out, for we often find the large compound 
corals broken off, turned over, and buried in the coarse 
transported shingle. Yet the long, tapering calyx of Zaphrevtis 
or AmpUxus cannot have been generally exposed to sand and 
pebbles travelhng by, and a great cauliflower-like mass of Litho- 
strotion hasaltiforme, one or two feet across, would soon show 
clear marks of what it had gone through had it been rolled 
into its present position wdth the well-worn boulders and pebbles 
of the underlying rocks. 
