EOCENE STRATA IN ENGLAND, BELGIUM, AND FRANCE. 105 



exclude the fluviatile shells, this is very nearly the proportion that 

 holds good in the Sundridge Beds. 



For these reasons, which might be extended, I do not see how the 

 quadruple divisions of Thanet Sands, Woolwich Beds, Oldhavcn Beds, 

 and Basement-bed can be maintained. Either the Oldhaven Beds 

 should go with the Woolwich or with the Basement-bed. In adopting 

 an alternative name, I feel there is now an objection to the use of 

 the term Basement-bed. So long as it was confined to a few feet 

 at the base of the large formation of which it seems to form part, 

 the term was suitable ; but if, as in this case it promises to do, it 

 becomes more important and individualized, it is better to use a more 

 distinctive term. At present the Basement and Oldhaven Beds have 

 not been recognized on the continent ; but from the greater dimen- 

 sions this zone attains in the Herne-Bay and Eeculvers clifi^s, and the 

 increase in its fauna, I consider it probable that it may be found to 

 correspond, when the fossils are more carefully compared, with some 

 of the upper beds of the Sables Inferieurs ; and I would especially 

 direct attention to the beds of Aizy and Sainceny, in the Soissonnais 

 and Oise, or to some of those between the Upper Landenian and the 

 Ypresian in the neighbourhood of Lille*. Therefore I think 

 Mr. Whitaker's term, »' Oldhaven Beds," is a better one than that of 

 the " Basement-bed of the London Clay," and wish that it may be 

 substituted for it, with, be it understood, the limitation I have 

 proposed, if such limitation be found correct. 



The London Clay. 



This needs no question. Its identity with the Lower Ypresian is 

 well established, and it is clear that, with the exception of the small 

 outlier near Dieppe, it is wanting in the Paris Basin, although it is 

 probably in part represented, together with the overlying sands, by 

 the beds of Ctiise-la-Motte, the argillaceous strata passing as they 

 range south into the fossiliferous calcareous sands of the Aisne and 

 Oise. 



The Lower Bagshot Sands. 



In the absence of fossils in the Lower and Upper divisions, and in 

 face of the similarity of composition, I grouped the three divisions 

 of the Bagshot in one series, of which the Middle division alone, which 

 has a definite relation to the Calcaire Grossier, formed the centre round 

 which the others were grouped; and the whole were made synchronous 

 with the Bracklesham Sands. At the same time I placed the Lower 

 Bagshots on the level of the Upper Ypresian, but, in the absence of 

 organic remains, left it as a member of the Upper Eocenet. This 



* I think it probable that the Upper or Sundridge division of the Woolwich 

 Series may be found to correspond with the Sainceny beds, and the Basement 

 or Oldhaven Beds with those of Aizy ; but a closer comparison of the fossils is 

 needed. 



t Quart. Journ. Geol. Soc. vol. xi. p. 240, pi. viii. 



