﻿388 8. V. Wood, j'un., Sf F. W. Harmer — The Eessingland Bed. 



posing that we have referred to it as a peculiarly Arctic shell. If he 

 had remembered that it is found now living eveiywhere on the 

 Norfolk coast, he would hardly have attributed to us such exceptional 

 simplicity. What we have contended is that this shell, which is 

 Arctic as well as West European, has not occurred in any bed of 

 Crag age, notwithstanding various assertions to the contrary ; and 

 that therefore as it does occur (and always in abundance) in every 

 fossiliferous marine bed of newer age than the Crag, it furnishes a 

 clear palseontological horizon by which to divide the Crag from beds 

 of Glacial age. With the exception of Turritella terebra, Pleurotoma 

 tumcula, Ostrea ediilis, and a species of Lacuna,^ all the marine 

 shells mentioned by Mr. Eeid as discovered by him in these Wey- 

 bourne sands will be found in the Lower Glacial column of the 

 tabular list in the '' Supplement to the Crag Mollusca," or in the 

 additions thereto given in the note to our joint paper in the Quarterly 

 Journal of the Geologicah Society for February, 1877; and it is satis- 

 factory to us to find, by the few additions only which have resulted 

 .from Mr. Eeid's lengthened stay upon and study of this coast, that 

 we had so nearly arrived, by our own researches, at the moUuscan 

 fauna of these Lower Glacial sands. 



Lastly. If we understand Mr. Eeid's paper aright, he thinks that 

 the beds between the Chalk and the Till on the coast constitute only 

 one formation, and that such formation is an estuarine one. This is 

 what we have always contended, only we add to it that this forma- 

 tion is the same as the pebbly sands described by one of us in 1866, 

 under the name of " Bure Valley beds," and afterwards by Prof. 

 Prestwich in 1870 under the name of " Westleton Shingle;"^ and 

 also that the Till is merely a continuation of the same deposit, due to 

 increasing depth of water combined with glacial action ; and this is 

 one of the very few things connected with the Glacial beds as to which 

 we feel no doubt. If the pebblj'' sands thus characterized by Tellina 

 Baltliica, which form the base of the Cromer Till (or Lower Boulder- 

 clay of Mr. Eeid and others), are to be rejected from the Glacial 

 formation, to which, although they may present no indications of 

 glacial action, they structurally belong, because their marine fauna 

 is not, as is the fact, more Arctic than the uppermost beds of the 

 Crag (though both contain several species of mollusca that now live 

 only in Arctic seas), then most assuredly the sands and gravels 

 which we term Middle Glacial should be rejected also from the 

 Glacial formation, because their molluscan fauna is even less Arctic 



^ The Cardimn Groenlandkum of Mr. Reid is no doubt the shell given in the tabular 

 list which accompanies the " Supplement to the Crag Mollusca," as Cardimn Jsland- 

 icum with a ? These imperfect decorticated specimens of Cardium cannot be identified 

 with any certainty. 



- It is not our business to defend Prof. Prestwich's identification of the shingle at 

 "Westleton with these Weybourne sands, which the gentlemen of the Survey impugn ; 

 but with respect to the identity which they discover between that shingle and the 

 mass which plunges into the Middle Glacial sand of Dunwich cliif, we beg to say 

 that this shingle (gravel) was several years ago, when that cliff could be ascended at 

 the spot, and closely examined, divided at one end from the Middle Glacial sand 

 beneath it by a denuded remnant of the Upper Glacial clay, in the manner shown in 

 Section R, which accompanies the map in the " Supplement to the Crag Mollusca," 

 and perhaps this remnant may still be found if looked for. 



