RED CRAG. 
79 
Mr. G. Scott^' in 1872 included in the Bed Crag beds of rough 
red'sand without shells, at the top, and described the bone-bed. 
Lyell in 1873t noticed the gradual lowering of tempera¬ 
ture shown by the shells of the Crags, those of the Coralline 
Crag representing a climate like that of the Mediterranean; those 
of the Bed Crag one like that of our own seas, and those of the 
Norwich Crag being almost Arctic. He thought that the large 
unrolled white-coated flints of the nodule-bed were probably 
carried by ice. 
Next year,J in describing the Red Crag, the same author 
compared it to shifting sandbanks, like those of the Dogger 
Bank. 
In the same year S. V. Wood,§ reviewing the pala 0 ontology of 
the Crag, remarked that species formerly abundant had of late 
eluded search, though within a few yards of, and at the same 
horizon as, the place of former occurrence; while some once 
thought rare had become more plentiful. He criticised the work of 
Jeffreys on Crag Mollusca, and thought that if any period can be 
called the cradle of the British Mollusca,” it is the Bed Crag 
rather than the Coralline. The list of extraneous fossils (of his 
paper of 1859) was thought by him to need additions. The only 
part of the Bed Crag free from derivatives is that at Walton 
Naze. The Bed and Fluvio-marine Crags and the Chillesford 
Beds he regarded as parts of one formation, during the accumula¬ 
tion of which only slight changes in the position of sea and land 
occurred. The lists of the Marine Mollusca given in Wood’s 
Monograph show almost the same per-centage of extinct forms in 
the case of the older Red Crag as in that of the Coralline. 
In this year Mr. Whitaker drew attention to a great extension 
of the Crag area, in the south-western part of Suffolk, around 
Sudbury. He also recorded the discovery of Bed Crag at 
Thaxted, in Essex. |1 
In 1877 Dr. J. E. Taylor, in an account of an excursion to the 
Crag District,^ suggested that the Baltic represents the condition 
of the later period of the Red Crag better than anything else, its 
water being partly brackish, with freshwater shells side by side 
with.marine ones, as in the Fluvio-marine Crag. 
S. V. Wood, jun., and Mr. F. W. Harmer^^ in the same year, 
referring to the unfossiliferous sand that often occurs above the 
shelly Crag, showed that it seems in some places to pass down 
into the Crag by thin seams of comminuted shells ; that at others 
the bedding is independent of the shelly Crag beneath ; and 
that sometimes it has the same oblique lamination as the Crag, 
* 19 Ann. Rep. Brighton Nat. Hist. Soc., pp. 64-68. 
t The Geological Evidences of the Antiquity of Man. Ed; 4. 8vo. London. 
pp. 248-254. 
% The Student’s Elements of Geology. Ed. 2. 8vo. London, p. 176. (1874.) 
§ Supplement to the Crag Mollusca. Part ii., pp. 190-221. (1874). 
11 Quart. Journ. Geol. Soc., vol. xxx. pp. 403-405. 
Proc. Geol. Assoc., vol. v. no. 3, pp. 108-113. 
** Quart. Journ. Geol. Soc., vol. xxxiii. pp. 74-78. 
