412 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 21 



lower part of wMch is generally the more clayey ; this bed has been 

 well named " striped sand and loam " by the Eev. H. M. De la Con- 

 damine*. As it is in the same position as bed 5 further east, I 

 have classed them together, though possibly they may not be the 

 same. 



Under London this part of the Woolwich Beds seems to be often 

 absent. (See Section 4, PI. XXII.) 



(5 b) Many of the London weUst have shown that a mass of mot- 

 tied plastic clays and sand, of the same nature as bed 2 h, comes on 

 above the clayj^shell-beds. This, therefore, may represent 5 ; al- 

 though, on the other hand, it may be a separate bed, and I have 

 therefore given it a separate index-mark. 



West of London 2 h and 5 h come together, the beds between hav- 

 ing thinned out, and form the well-known plastic clays and sands of 

 Reading, &c., where there is nothing but these and the thin bottom- 

 bed between the London Clay and the Chalk. 



§ 4. Oldhaven Beds. 



Up to this point my nomenclature has followed that of Mr. Prest- 

 wich ; but with regard to the sands and pebble-beds next below the 

 London Clay in a great part of Kent^ I am obliged to differ from 

 him — the difference, however, being not as to the position of the 

 beds, but only as to their relation to those above and below and as 

 to what they should be called. 



Mr. Prestwich has, though with some doubt, classed the greater 

 part of the pebble-beds of Blackheath, (fee, and the uppermost sands 

 of Upnor and the Reculvers with his " basement-bed of the London 

 Clay," taking them to represent the pebbly loam which occurs at the 

 bottom of that formation on the west J. To this I objected in a 

 paper read before this Society about four years ago §, as the layer of 

 pebbles in clay which on the sou;;h-east of London occurs at the bot- 

 tom of the London Clay, and is the"*:efore its basement-bed, overlies 

 the thicker sandy pebble-beds. Moreo zer in some places the two are 

 separated by a layer of sand. 



I thought therefore that the sandy pebble-beds should be classed 

 rather with the Woolwich Series, and inferred that the highest sands 

 of Upnor, &c., would follow the same classification. Since then, 

 however, I have had the means of learning much more of the " Lower 

 Lor don Tertiaries," and am bound to say that the knowledge thus 

 gained has led me to a greater agreement with the views of Mr. 

 Prestwich, as I took the first chance of stating ||, and to acknow- 

 ledge that the classing of these sands and pebble-beds with tho 



^^ Quart. Journ. Geol. Soc. vol. vi. p. 441. 



t Prestwich, Quart. Jom-n. Geol. Soc. vol. x. pp. 76, 142-144, 148-151. 



J Quart. Journ. Geol. Soc. vol. vi. pp. 254, 255, 261-265, and vol. x. pp. 105- 

 107, 110, 111, 330 (note), 



§ 3id. vol. xviii. pp. 267-268. The section at Bicklev was reopened after 

 my paper was published, in order to get ballast for the railway. 



II Geol. Survey Mem. on sheet 7, p. 24. See also a short account of the Ter- 

 tiary Beds of Kent in the Geologist, vol. vii. p. 57 (1863). 



