and its Organic Remains. 83 



6 



several estuaries, which having extended a few miles into the 

 interior, terminate at the junction of the crag with the com- 

 mon diluvium of the country. The banks of these estuaries 

 are generally low, or slope so gradually as not to furnish advan- 

 tageous sections of the district through which they pass. The 

 crag, however, is exposed in several places at a village called 

 Ramsholt, on the eastern bank of the Deben; and here an en- 

 tirely new feature presents itself. 



Beneath the common stratum of shells and pebbles is a bed 

 of sand devoid of that peculiar deep tinge which so generally 

 accompanies the crag-formation : this bed is in contact with 

 the London clay, and contains a great assemblage of organic 

 remains; but these exhibit so novel a character, and the cir- 

 cumstances under which they were deposited were evidently 

 of so different a nature from those of the superior stratum, as 

 at once to strike the attention of the most casual observer. 

 My object in the present paper will be principally to establish 

 the following position : — That the circumstances attending the 

 formation, and the difference in the organic remains of these 

 beds, indicate their having been deposited at distinct periods. 



The term Red Crag may be appropriately applied to those 

 beds which constitute the upper and most extensive part of 

 the formation, while I propose to designate the lower as the 

 Coralline Crag, for reasons which will in the sequel appear 

 sufficiently obvious. 



It is now some years since I first observed at Tattingstone, 

 a village situate on the western boundary of the crag, and be- 

 tween the rivers Orwell and Stour, that a quarry had been 

 worked to a greater depth than usual, when, instead of reach- 

 ing the London clay, a stratum had been exposed containing 

 several shells which were then new to me. Many of these had 

 the corresponding valves in contact, a circumstance of un- 

 usual occurrence ; and the deposit altogether presented an ap- 

 pearance differing in many respects from that of any part of the 

 crag with which I had been previously acquainted. I subse- 

 quently met with the same shells, associated with similar pe- 

 culiarities of deposition, in Sudbourne Park, (the occasional 

 residence of the Marquis of Hertford,) about twenty miles 

 eastward of Tattingstone. It was not, however, until the dis- 

 covery of a corresponding stratum at Ramsholt, where the or- 

 ganic remains exceeded in number and excelled in preserva- 

 tion those of any other locality, that my attention was parti- 

 cularly drawn to the consideration of the subject. 



The relative depth of the strata in the different localities 

 was as follows : 



Tattingstone. Alluvium and gravel, 4- feet. 



M2 



