RED CRAG, 
75 
K. A. 0. Godwin-Austen* in the same year criticised the per- - 
centage test of age as liable to fluctuation; parallelled the 
Scaldisian beds of Antwerp with the Eed Crag, both consisting 
largely of derived shells; limited the Crag sea in Suffolk at 
Bentley, Ipswich, and Woodbridge, but included as of Crag age 
beds which are now knov/n to be later, such as those of Grays 
and Kelsey. He likewise gave a map of the Crag-sea area. He 
thought that there is a great break between the Crag and the 
Boulder Drift, 
In the same year S. V. Wood,t controverting Mr. Fisher’s 
conclusion, noted above, agreed with that of his son, as to the 
passage upwards of Bed and Norwich Crag into Chillesford Beds, 
and gave the name Scrobicularia Crag to the top, or horizontal, 
stage of the Eed Crag. He referred chiefly to palaaontological 
evidence, which shows one of the most rapid faunal changes, 
measured by the thickness of the beds in which it occurs. The 
oldest part of the Eed Crag is, he thought, palgeontologically 
nearer to the present time than to the Coralline Crag; and the 
newer deposit shows evidence of change by stages, the oldest 
having some affinities with the Coralline Crag, but more with 
the Mediterranean sea, whilst the newer stages have few shells, 
and those of northern type. The oldest stage is that.of Walton 
Naze, the fauna of which shows a connection with more temperate 
seas, and an absence of northern forms. The next division is 
that from which were got the chief part of the shells described 
in the Monograph on the Crag Mollusca, and which occurs 
between the Stour and the Deben, and on the left bank of the 
estuary of the latter : it has mostly a highly oblique bedding, 
referred to beach action ; shows an intermingling of the W alton 
fauna with the northern one of the succeeding horizons; and 
includes some shells probably derived from the Coralline Crag. 
The next division occurs around Butley, Chillesford, and Sud- 
bourne, and though in structure like the last, has a dissimilar 
fauna, but with many forms that occur at Sutton. Above this 
is the uppermost division of the Eed Crag, marked by the 
incoming of Scrobicularia piperata^ the fauna of which is small 
in number of species. Separated from this by a few feet of sand 
is the Chillesford sand (Mya-bed of Mr. Fisher). S. V. Wood, 
jun., added some diagram-sections in illustration, with a list of 
the actual sections on which they are based. 
In 1868 E, A. C. Godwin-AustenJ gave a summary of our 
knowledge of the Crag, reviewing the conditions under which it 
was deposited, remarking that the Eed Crag is a complex assem¬ 
blage, in spite of its small vertical size, and that at Walton Naze 
alone do we find this old sea-bed in its original state, undisturbed, 
elsewhere the Eed Crag being re-arranged and relatively of shallow 
water accumulation. 
* Quart. Journ. Geol. Soc., vol. xxii. pp. 229-232, 2137-239, 245, 246. 
f Ibid., pp. 538-552. 
j Geol, Mag,, vol, v. pp. 469-478 ; Geol. Nat. Hist, Repertory, vol. ii. p. 229 j 
and Rep. Brit. Assoc, for 1868, Sections, p. 70. (1869.) 
