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CHAPTEE III. 
CORALLINE CRAG. 
Though the shelly sands locally known as Crag have been 
worked and their fossils collected from a very early period, it was 
not till 1835 that it seems to have been suspected that two 
distinct deposits with different faunas were included under this 
name. Previous observers took the Red Crag to be merely 
composed of the debris of the lower bed. In the year 1835 
Mr. Charles worth* read a paper in which the Crag was shown to 
be divisable into an upper, or Red Crag, and a lower, or Coralline 
Crag. The Coralline Crag was so named from the Corals ” 
(Bryozoa) found in it. They are repeatedly alluded to by 
Mr. Charles worth, who, speaking o£ the pits at Sudbourn and 
Orford, mentions ‘‘ the abundance of corals, many of which are 
extremely beautiful, and distinct from recent species. These 
corals sometimes occur in a loose sandy grit, fj.’om which they are 
readily detached; but it frequently happens that the stratum is 
almost wholly constituted by them, numerous species and genera 
•indiscriminately growing upon one another, the interstices being 
filled with sand, dead portions of coral, comminuted shells, and 
other extraneous substances, all of which have become cemented 
together, occasionally forming a rock sufficiently compact for the 
purposes of building.’' 
Mr. Charles worth had thus at this early date thoroughly 
grasped the characteristic features of the deposit, and had not 
only done so but had recognised that the main mass at Sudbourne 
and Orford and the sections at Aldborough, Tattingstone, and 
Ramsholt all belong to one period, older than the Red Crag. 
The objection has since been made that true corals are rare in the 
Coralline Crag, and that the “ corals ” of Mr. Charlesworth are 
now known to be Bryozoa (Polyzoa); the terms Bryozoan Crag or 
White Crag have therefore been proposed. There seems, however, 
no reason for changing the very appropriate name given by 
Mr. Charlesworth, for in popular parlance bryozoa, such as occur 
so abundantly in the Coralline (^rag (see Fig. 3), are corals, and 
one will often find marked on the Admiralty charts soundings 
with coral ”—meaning any coral-like organisms, either bryozoa, 
true corals, or gregarious tube-inhabiting annelids. Even long 
* Phil. Mag., ser. 3, vol. vii. pp. 81-94. (1835.) Abstract in Proc. GeoL Soc., 
vol. ii. No. 41, pp. 195, 196. 
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