300 E. B. POIJLTON ON MAMMALIAN KEMAINS AND TREE- 



(/). This contains traces of vegetable matter in which no structure 

 can be made out ; and there is much oxide of iron in the layers and 

 concentrically laminated nodules. I found in this clay a few 

 rounded flints still retaining their green coating and thus proving 

 that the materials had partially been derived from the lowest bed of 

 the Woolwich and Reading series, the layer of green-coated flints 

 just above the Chalk. This rendered probable the view that the , 

 laminated clay itself was derived from the destruction of the Leaf- 

 beds, which occur just above the green-coated flints in the undis- 

 turbed Eocene strata. The clay much resembles that of the Leaf- 

 beds in its blue colour. The sandy intermixture is, of course, a 

 newly imposed character given during the redeposition among these 

 beds of sand. The clay is horizontal west, but east it descends a 

 steepish slope ; and towards the bottom of this a large tree-trunk (cc) 

 is seen, partially enclosed in the clay, and exposed in transverse 

 section. The relation of the tree-trunk to the slope gives the im- 

 pression that this water-logged mass, rolling down under the slow 

 action of the current from the west, has been the cause of the 

 cutting away of (e) to a slope, while further west the beds (b) and 

 (d) are planed off horizontally. Purther probability is given to 

 this view by the fact that east of the trunk the clay-band again be- 

 comes horizontal before it dies away, in a few feet. 



Imbedded Remains. These have nearly all been found in the ex- 

 cavations at this north face ; and hence the whole organic remains of 

 the pit are best described here, since nothing different has been 

 found in other parts. Omitting the indication of man by the flake 

 probably belonging to the gravel (A), the remains of the pit are of 

 three kinds — Mammalian bones and teeth, tree-trunks, and derived 

 shells. 



Mammalian Remains. These have been partly found in the gravel 

 (A) and partly in the sand B (6). Many were found in the laminated 

 coarse sand marked (a) to the west and below, thus occurring quite 8 

 feet below the under surface of the gravel (A). The bones and teeth 

 were distributed in various directions to different collectors ; and 

 those from the gravel and sand have been indiscriminately mixed. 

 The difference, however, is generally easily recognizable, remains 

 rom the gravel being broken rather than waterworn, usually 

 stained yellow with iron oxide, and sometimes still showing the 

 smaller constituents of the gravel adherent to their surface, while 

 those from the sand are more waterworn and whiter. In some 

 cases I have direct testimony as to the beds in which they were 

 found. The identification of the species, or even in some cases 

 naming the bones, was extremely difficult ; but putting together the 

 characters of the bones and teeth, the following list was made out, 

 and may be taken as trustworthy : — 



Elephas primigenius. 



(1) Two perfect molar teeth of young individual between sand {b) and gravel 

 (A), also fragments of teeth frojn gravel. 



