1865.] riSHER CHILLESFORD BEBS. 27 



ing a line from the spot where the Mya-bed occurs on the beach to 

 the pit at Yarn Hill, which is scarcely raised above the sea-level, and 

 bearing in mind that the outcrop on the coast has been carried be- 

 neath the beach towards the south by the encroachment of the sea, 

 we obtain a dip towards the south-west. 



Proceeding to Wangford, we meet with pits in the true Norwich 

 Crag, exactly resembling the deposit at Thorpe, near Aldborough, and 

 at the pits about Norwich. It is a gravelly deposit of considerable 

 thickness ; how thick the section does not show, because the upper 

 part is denuded, but about 9 feet remains. The shells are not grouped 

 as in the Mya-bed, the proportion of univalves being greater. None 

 of the bivalves are in pairs. Here I found an antler of a deer, but 

 too much decayed for removal. 



I dug in the floor of this pit and found the Crag to rest on a lami- 

 nated sandy loam, closely agreeing with the upper part of the Chil- 

 lesford Clay at Easton Bavent CUif. The dip of the beds to the south- 

 west, as determined above, agrees well with this identification. 



There is another pit, which I had not time to visit, at Bulcham 

 Workhouse. I am told by Mr. Wood, jun., that it is in the Norwich 

 Crag. Its position would agree very well vdth the view I take of its 

 superposition on the Chillesford Clay. 



Thus the observations I was enabled to make in the neighbourhood 

 of Southwold confirm my former view, that the descending order of 

 sequence is — 



1. Norwich Crag, 



2. ChiUesford Clay, 



3. Mya-bed; 



while they give the additional fact that the Mastodon and other 

 Mammalia have been procured from the Mya-bed at Easton Cliif. 

 We cannot, then, hesitate to include the Chillesford Clay in the Nor- 

 wich Crag series. 



I am not aware whether the Chillesford Clay occurs in the Norfolk 

 district of the Crag, where it rests immediately upon the Chalk. 



There can be no doubt about the Chillesford Clay being a marine 

 deposit, for I found in it a lenticular patch of sand containing shells 

 similar to those of the Mya-bed ; and Mr. Prestwich and Mr. Wood 

 found marine shells in it at Chillesford. The character of the deposit 

 might othervnse have led one to suppose that it was lacustrine. 



There are still some problems of considerable complexity to be 

 solved respecting the sequence between the Mya-bed and the Eed 

 Crag, and again from the Norwich Crag upwards. 



It is well known that in the district of the Red Crag there are 

 thick beds of reddish-brown sand overlying the fossiliferous Eed 

 Crag. These have been called " the unproductive sands of the Crag"*. 

 Mr. Wood, jun., considers them to belong to his " middle drift," and 

 thinks that the Chillesford beds are a local modification of them. I 

 am not prepared to deny that the Chillesford beds, and therefore also 

 the Norwich Crag, may be a local modification of these sands ; but I 



* Prestwich, Quart. Journ. Geol. Soc. rol. x. p. 93, note. 



