96 
RED CRAG. 
Fig. 20. 
Section in the Red Crag at Ramsholt,* 
(Prestwich.) 
*Seam of copro- 
lites. 
Red Crag with 
few shells and 
some copro- 
lites; 10 feet. 
^Shelly Red Crag; 
3 feet. 
Probable level of 
Coralline Crag. 
The south-western part of the cliff at Bawdsey exhibits some 
of the clearest sections of the Red Crag and is one of the best 
places for collecting. It must not be forgotten, however, that here, 
as is always the case in the Red Crag, a hasty visit will only 
produce some twenty or thirty species, the others being rare, 
and only discovered after long search. Bawdsey, an incon¬ 
venient place to reach, and is perhaps best examined from Felix- 
stow—there is a Ferry across the mouth of the River Deben. 
North of Bawdsey there are no more cliffs for several miles, the 
coast line being occupied almost entirely by the Allimum of the 
River Ore, and by shingle beaches. 
The next sections of interest are those exposed at different 
times in the coprolite works on the marshes of the Butley River, 
near Boyton and Butley. Here the Nodule Bed is found beneath 
the Alluvium, and sections are only visible while the pits are 
actually being worked, for at other times they are full of water. 
A large number of shells is obtained here, but as the Nodule 
Beds of the Coralline and Red Crag are both found, and 
are scooped out of the water and mixed in the works, it is 
impossible to say which species belong to the one formation and 
which to the other. Besides this the base of the Red Crag is 
undoubtedly full of derivative Coralline Crag shells, and we have 
the additional complication, hrst pointed out by S. V. Wood, that 
there is a constant tendency for the Red Crag itself to be partly 
eroded and its shells to be re-deposited on a slightly higher zone. 
The Butley fauna may thus be leavened with derivative shells 
from every horizon between the base of the Coralline Crag and 
the upper Red Crag. The contemporaneous shells of these pits 
are probably the northern and arctic forms, but Cassidaria and 
other Mediterranean species occur in such a perfect state of 
preservation that it is impossible to separate them. Valuta 
Lamherti is abundant, as are Cardita senilis and Astarte Omalii, 
both of which are probably only present in the Red Crag as 
derivative fossils from older strata. 
Quart. Journ. GeoL Sac., vol. xxvii., p. 327. (1871.) 
