532 Mr. Charlesworth on the Crag, and on ascertaining 
them to particular spots or habitats; thus we find that the 
beds of crag shells are not continuous but deposited in patches; 
and that the shells in the Suffolk beds are in numerous in- 
stances generically and in almost all specifically different to 
those found near Norwich.” No traces of the coralline cra 
have yet been detected in the county of Norfolk; it should 
therefore be borne in mind that the above observations refer 
solely to the upper deposit. 
We are here furnished with the clearest evidence that 
Messrs. Woodward and Taylor agree in one important par- 
ticular; viz. that the fossils of the red crag are not promis- 
cuously jumbled together, but localized very much in the same 
manner as the Mollusca inhabiting our present seas: both geo- 
logists also infer from the great accumulation of these fossils 
that the ocean must for a long time have remained stationary 
over that district in which they occur. 
In order then to maintain the decisions in reference to this 
subject which [appeared in your Number for November, it 
will be necessary either to dispute the accuracy of the facts now 
adduced, or to show that this gregarious distribution of ge- 
nera and species may exist in a formation resulting from those 
operations which we designate by the term diluvial. I will- 
ingly admit that the views of geologists as to the real na- 
ture of these operations are not of the most definite charac- 
ter, and at the present time our opinions respecting the true 
origin of what are called diluvial deposits are undergoing im- 
portant modifications; but allowing the utmost latitude for 
any discordance of this kind, I apprehend that it will require 
more than ordinary ingenuity to show that the conditions 
which prevailed at the time when the formation of the crag 
was going forward can in any way be approximated to that 
state of things which is generally understood to be the ne- 
cessary concomitant of diluvial action. 
Those who are at all familiar with the geology of Nor- 
folk, cannot fail to have observed that the crag, in common 
with other formations, has been subjected to the abrasion of 
diluvial currents. Mr. Taylor remarks that * portions pro- 
bably from its western edges have been swept away. Their 
fragments mingled with those of the chalk and preceding 
formations, piled in enormous heaps, form the cliffs of Cro- 
mer and Trimmingham, 250 or 300 feet in thickness upon the 
original crag which rests in situ at their base.” 
I imagine that it would not greatly increase the reputation 
of any geological observer to infer the diluvial origin of the 
Norfolk chalk, because its fragments in the shape of detritus 
occur in the cliffs at Cromer ; but a precisely analogous fact has 
