4 
INTRODUCTION. 
The marine Newer Pliocene deposits were in all probability 
of much smaller extent than the older series originally, but 
denudation has affected them less. The area occupied by the 
Ked, Norwich, Chillesford, and Weybourn Crags is now con¬ 
siderably greater than that of the older series, though on the 
other hand, its present western limit is probably not far from the 
original shore-line. The upper Crag occupies the eastern half 
of Norfolk and Suffolk, and extends a short distance into Essex. 
It seems formerly to have stretched as far south as the Black- 
water. Leaving out of account the small gaps caused by recent 
and glacial denudation, the total area over which the upper Crag 
can be traced amounts to about 1,200 square miles. We must 
also not forget that this is only the western margin of a deposit 
which dips beneath the North Sea, and perhaps stretches con¬ 
tinuously to Belgium and Holland, where it re-appears as the 
Scaldisian or Upper Crag. 
No deposits of this age are known in any other part of Britain, 
thouj^h the occurrence of derivative Crao; shells in the Drift of 
Aberdeenshire seems to show that beds like the Bed Crag must 
occur beneath the North Sea somewhere in that neighbourhood. 
The next division, the sub-aerial, freshwater, and estuarine 
deposits, known as the Cromer Forest-hed, occupies only a limited 
area. It extends along the Norfolk and Suffolk coast for about 45 
miles, but its inland boundary cannot be fixed, owing to the great 
thickness of the overlying Drift, and for some distance on each side 
of Yarmouth it is also invisible, though probably occurring beneath 
the sea-level. There is a small outlier of mammaliferous gravel 
containing a similar fauna, at Dewlish in Dorsetshire. Otherwise 
nothing that can be referred to this subdivision of the Pliocene 
series is known beyond the limits of east Norfolk and east Suffolk. 
Capping hills in various parts of the east and south of England 
there are, however, outliers of gravel which, fi om their peculiar 
character and position, seem to date from before the Glacial 
Epoch. These will be described in Chapter X., but as they are 
all unfossiliferous, and perhaps of very different ages, their distri¬ 
bution has not been marked on the map at the beginning of this 
volume. 
It will be observed that reference is constantly made in the 
following pages to the foreign equivalents of the different strata 
under discussion. This is done, not with the object of referring 
our Pliocene strata to divisions established beyond the limits of 
this country, or to arbitrarily selected “ types,” but to prevent the 
thin series in England from being taken as in any way forming a 
stratigraphical and palaeontological standard. It so happens that 
England has by far the most complete series of Pliocene deposits 
of any part of Northern Europe, and the strata here are more 
generally fossiliferous. In the Mediterranean region, however, 
the series is much more complete, especially in Italy. We find 
the period represented there by so enormous a mass of deposits, 
that our ideas of its importance are greatly altered. We also 
