302 E. B. POTJLTON ON MAMMALIAN REMAINS AND TREE- 



readily into its component fibres on being merely touched with the 

 needle ; and these, when examined with a No. 4 Hartnack, in the 

 manner mentioned above, showed all the characteristic appearances 

 of the tissue of Pinus. fragments of the medullary rays were seen 

 quite distinctly crossing the pitted vessels at right angles. I have 

 to thank Prof. Lawson for his kind help in working at, and making 

 out the structure of, the wood. 



Derived Uemains. Between the sand and gravel, where these 

 come into contact and the clays are absent, a curious admixture of 

 derived and proper remains occurs. As shown in the above list, teeth 

 of horse and Elej)has and a bone of horse were found here ; but with 

 them were the following derived remains : — 



(1) Ostrea dilatata, from the Oolites at Oxford, abundant but worn. 



(2) Worn fragments of Inoceramus from the Chalk ; and a worn Belemnite, 



probably from the same source. 



(3) Ostrea bellovacina from the Woolwich and Reading Series. Abundant 

 and perfect. 



(4) Shell-masses from the basement beds of the London Clay, with many of 



the shells still very perfect and recognizable {Natica, Fectunculus, &c.). 



This heterogeneous collection, found at one horizon only in the 

 deposits, serves to indicate the diverse and widely separated strata 

 from which the bed has been formed. 



I was anxious to procure the entire section of this interesting 

 and very perfect face, and thus to gain a complete knowledge of all 

 the beds over the Chalk at this point. However, on digging at the 

 base of the sands, water came in at all points along the face. This 

 is held up by some clay-bands above the Chalk ; and their top was 

 reached by the spade. The clay may be the reconstructed Leaf- 

 beds, or perhaps these beds continued under the reconstructed sands 

 in an unaltered condition. The sand was so full of water at this 

 level (about 1 foot beneath base of cliff) that we could not com- 

 plete the section. Hence in fig. 1 the face terminates below in 

 a water-line. To reach the Chalk we chose a spot 78 feet south of, 

 and at right angles to, the east end of the north face, just under the 

 imperfect and irregular east face of the pit. Here we suffered no 

 inconvenience from the water, and the Chalk was reached in about 

 5 feet. The pit was dug by Mr. E. W. Andrewes (my friend and 

 former pupil) and myself ; and I must express my hearty thanks to 

 Mr. Andrewes for his help in the really considerable labour of 

 cutting through the stiff clay, as well as for many other services 

 in connexion with this work. The owner of the pit, Mr. Winter, 

 kindly gave us permission to do as we liked, and afforded us every 

 assistance in his power. The pit sunk was 5 feet long by 2 feet 

 wide ; and the Chalk was seen at a point 5 feet 4 inches below the 

 greatest depth reached by the men, and as nearly as possible 30 feet 

 from the surface. Careful measurements of the beds dug through 

 in the pit, and those above, gave the following results. The dotted 

 vertical line (AB) in fig. 2 shows the section here described : — 



