CORALLINE CRAG. 
27 
described the whole of the Coralline Crag district.* Most of 
their notes will be found incorporated in this chapter. 
The Coralline Crag, though occupying so small an area, is a 
formation of considerable importance to the geologist, owing to 
its extremely varied fauna and exceptional lithological character; 
it must, therefore, be described more fully than will be necessary 
with some of the other divisions of the Pliocene series. As the 
Geological Survey, however, has been able to add little to our 
knowledge of this bed, and as many of the older observers saw 
sections now invisible, and in many cases had pits dug so that 
they might more thoroughly study the deposits, the following 
account of the sections in the Coralline Crag must be largely 
taken from the work of previous observers. Use therefore has 
been freely made of the published papers by Mr. Chariesworth, 
Lyell, Prof. Prestwich, and S. V. Wood, sen. and jun., especially 
where their notes refer to better sections than are now visible, 
but at the same time, that the student may not be led to search 
for pits long since overgrown, a note is added of the present state 
of the exposures. All the localities were re-examined by the 
writer of this Memoir in 1886 and 1889. 
Commencing at the northern extremity of the formation, the 
first indications of Coralline Crag are the sunk rocks off Sizewell 
and Thorpe. Two or three miles further south the Crag was 
formerly seen under the beach at Aldborough, but the sections 
are now sloped and built over, and this is the only place where 
the deposit has been found on the coast. 
Inland at Aldborough, near the Red House, there are pits on 
both sides of the high road. Another pit will be found about 
100 yards north of Aldborough Hall, and from this was obtained 
the very perfect crab {Cancer 'pagurus) now in the Museum of 
Practical Geology. Further west, on the north bank of the 
River Aide, opposite Stanny Point, the Coralline Crag forms a 
low cliF of loose brashy rock. The pits near Aldborough are 
not good places for collecting, as the aragonite fossils are usually 
only in the state of casts, though bryozoa are often particularly 
well preserved. Crustacea also would seem to be exceptionally 
perfect, for besides the crab already mentioned. Prof Prestwich 
speaks of a beautiful specimen, found by Mr. Norman Evans, 
probably referable, according to Dr. H. Woodward, to Gonoplax 
angulata, Leach. Prof. Prestwich thinks that near Aldborough 
the upper division of the Coralline Crag is alone exposed; all the 
pits are certainly in rubbly limestone of the same character, and 
the base of the deposit is nowhere reached. 
On the south side of the River Aide, these beds reappear at a 
somewhat higher level, so that the upper part of the lower divi¬ 
sion skirts the marsh. At Iken Brickfield, about half a mile 
west-north-west of Calton Farm, Prof. Prestwich recordedf thirty 
Ipswich, Hadleigh, and Felixstow (1885), and Aldborough, Framlingham, Or- 
ford, and Woodhridge” (1886). 
f Quart. Journ. Geol. Soc., vol. v. p. 347 (1849). 
