552 <A. R. Horwood—Post- Pleistocene of Central England. 
beaver, wolf, fox. In the buttery clay marine shells occur, viz. : 
Ostrea edulis, Cardium edule, Scrobicularia piperata. Foraminifera 
have also been found, and remains of marine mammals, whale, and seal 
are not uncommon. 
In the alluvium of the Old Fen lakes or meres of Whittlesea, 
Ramsey, Ugg, etc., the alluvium or silt is crowded with Unio, 
Anodon, Paludina, Planorbis, Limnea, forming a shell marl. The 
alluvium of the present rivers contains also a considerable flora 
and fauna, and consists of black loam or silt, reformed by modern 
rivers, and continually being augmented year by year. In the Nene 
and Welland valleys these are very extensive. In the Fens the 
marine alluvium or warp is found near Crowland, and resembles the 
silt found associated with peat at a lower horizon. 
VALLEY oF River Nene. 
an a fissure of the Lincolnshire Oolite at Brigstock, Mr. A. Wallis 
found recent land and freshwater shells, and Mr. Beeby Thompson! 
explained their occurrence as due to ‘disturbance of Lincolnshire 
Oolite and redeposition with introduction of the shells at the time of 
the latter. He suggests their pre-Glacial age, and preservation in 
Interglacial clay. This would lend support to the earlier age of the 
shells at Casewick, also in a fissure. In a later paper Mr. Beeby 
Thompson? includes these shell deposits in the late mid-Glacial 
gravels, which underlie the Upper or Chalky Boulder-clay. 
The shells that were found were— 
Succinea putris. Helix nemoralis or arbustorwn, 
Cochlicopa lubrica. Pupa marginata. 
Helix pulchella. Pisidium pusiliun. 
- In valley gravels lephas antiquus, E. primigenius, Rhinoceros 
tichorhinus, R. leptorhinus, Hippopotamus major, Equus caballus, Bison 
priscus, Bos primigenius are found, tusks and teeth in the upper 
part of the Nene Valley, lower down near Peterborough marine shells, 
Cardium and freshwater species of Physa, Limnea, Planorbis. At 
Elton and Northampton Mammoth occurs. 
In river alluvium at Martin’s brickyard Mr. H. N. Dixon * found— 
Nuphar luteum. Polygonum. 
Stellaria media. Mercurialis perennis. 
Prunus spinosa. Alnus. 
P. padus. Corylus avellana. 
Sambucus nigra. Quercus robur. 
Mammalia, Bos longif/rons and B. primigenius, horse, sheep, wild 
hog, red deer, freshwater mollusca, and human remains, often coated 
with vivianite, also occur. 
For comparison with localities farther removed from the central 
tract of Leicestershire, we add a list of plants, etc., found outside the 
midland or central tract. At Dursley, Gloucestershire, to the south- 
west, a calcareous tufa in process of formation is full of leaves. 
Miss M. A. and Mr. Clement Reid‘* found leaves of hazel, elm, and 
hart’s tongue in it. 
' Grou. Maa., 1895, pp. 1-3, reprint. 2 Proc. Geol. Assoc., 1910, p. 485. 
5 The Origin of the British Flor a, Clement Reid, F.R.S., 1899, p. 138. 
* Thid., p. 66. 
Eo 
