476 Reports and Proceedings — 



having its own proper fauna, of which the Bryozoa form a very large 

 proportion. The examples of this condition of sea-bed occur only in 

 Suffolk, where they are now about 40 feet above the sea-level. 

 Assigning to these beds depths of 40 fathoms, a difference of 300 feet 

 is the least that can be assumed as that of their original, compared 

 with their present positions. It is the lowest condition, or the 

 deepest, of which our English area offers any illustration. It does 

 not occur over any part of Belgium, where the lowest beds above the 

 sea-level belong to the deep-sea deposits of ooze, or to the 100 

 fathoms depth. 



The Eed Crag, though a good division for the time when it was 

 proposed, is a complex assemblage, in spite of its small vertical 

 dimensions. Of all that was originally so grouped, a very small 

 portion only (that of one locality) can now be referred to as such, 

 namely, the Crag at Walton Naze ; in this alone is to be found 

 an old sea-bed, a marine-life zone, undisturbed since its original 

 accumulation. 



The Ked-Crag beds of the valleys of the Stour, Orwell, and Deben, 

 though referable to some part of the same general period, are wholly 

 rearranged or remainie beds and of the later stages of the Crag-sea ; 

 they are, relatively to the Walton beds, very shallow-water accumu- 

 lations, presenting that diagonal mode of deposit, known as false- 

 bedding, indicative of surface disturbance and tidal movements. 

 Above them, in places, and on the land side of them, are certain 

 thick accumulations of red coarse sands, which have also been re- 

 ferred to the Eed Crag, and which at one time I supposed to repre- 

 sent a more marginal sea-zone, the ordinary Eed Crag being that 

 condition of sea-bed known as dead-shell sand and gravel. 



The shell-gravel of Antwerp corresponds with the Eed Crag of 

 Suffolk. Additions were subsequently made, as in the case of the 

 Chillesford Crag of Prestwich, and the Bridlington Crag. 



With respect to the recognition of the fossil shells of the Crag 

 and the use made of such guides, M. Deshayes, in 1831, proposed 

 (Ann. des Sc. Nat.) three zoological groups for the whole of the 

 marine series of formations above the Chalk. Of these, the oldest, 

 or Nummulitic, contains a marine fauna which is wholly extinct. 

 The middle is what may now be termed older Kainozoic ; and it was 

 in his upper or modern group, which included the sub-Apennine and 

 other continental sea-beds, that the whole of the English Crag was 

 included, as comprising a large proportion of living forms. 



The Norwich, or Fluvio-marine Crag, the uppermost of Mr. Charles- 

 worth's classification, was for many years the subject of differences 

 of opinion, as to its value and distinctness as a division ; it had also 

 gradually been made to include much more than at first : any bed 

 containing either Mammalian and Molluscan remains, or even an 

 admixture of fresh- and salt-water mollusca, in any part of Suffolk 

 and Norfolk, had come to be put down as the equivalent of the 

 Norwich Crag. 



General opinion seems now to have come round to the view 

 which some geologists had long since taken. Writing in 1865, Mr. 



