and on the Drift of the Eastern Counties. 189 
with both valves united, and univalves with the pullus unim- 
paired. This bed, lying at the southernmost extremity of the 
deposit, presents the only instance of Red Crag, other than that 
of the fifth stage, which has been deposited under water; and 
it is destitute of those derivative Coralline-Crag shells that so 
largely contribute to make up the mass of the rest of the Red 
Crag. The rest of the Red Crag, occupying as it does a hollow 
between the Coralline Crag on the one side and the London- 
Clay shore on the other, is largely composed of the degraded 
material of the Coralline Crag, as well as having been in each 
successive stage largely made up of the degraded material from 
the preceding stages. 
The fifth stage, or horizontal and water-deposited Crag, does 
not uniformly cover the underlying beach stages; these, deeply 
furrowed on their surface, are very frequently covered only by 
the red sands of the lower Drift; while the manner in which 
the fifth stage spreads up to and over the beach stages (almost 
always the fourth) shows that it has been formed in channels 
cut through the pre-existing beach, and afterwards silted up. 
It is under this fifth-stage Crag alone that the workings of 
phosphatic nodules, so far as I have seen them, occur*. I learn 
from Mr. Colchester that this material has been obtained from 
beneath the Coralline Crag; but not only have all the nodule- 
workings in the Red Crag that I have visited been under this 
stage, but wherever the beach stages are to be found resting 
on the Clay, as at Bawdsey and Walton, the nodule-band does 
not occur. This band, often of nearly a foot in thickness where 
worked, and largely intermingled with rolled Pectunculi, thins 
off gradually as the fifth-stage Crag leaves the Clay and rises 
over the beach stages. I have traced it so rising in numerous 
instances. At the watercourse near Methersgate Dock, Sutton, 
it appears overlying beach stages, whence, going eastwards, 
the extensive (but now discontinued) nodule-workings imme- 
diately over the London Clay occur ; and on quitting them, the 
band rises again, on the eastern side, over beach stages. At 
Bawdsey the band first occurs high up in the cliff, covering 
beach stages, and descends to the southwards towards the river, 
nearer to which, and inland, extensive workings have taken 
place. At Tattingstone it occurs at the top of the section, 
underlying fifth-stage and covering beach Crags, while at the 
junction there of the beach Crag with the Coralline Crag it is 
* At the base of the beach Crags small nodules may be found, forming 
a thin band interspersed with Crag; but they are intermixed with pebbles 
in such proportion that the pebbles are to the nodules as nearly 10 to 1. 
There is no similarity whatever between these minute bands and the true 
Pectunculus-vein of nodules. 
