180 
ON THE NON-MARINE MOLLUSCA FROM THE 
HOLOCENE DEPOSITS AT LONDON WALL AND WESTMINSTER. 
By A. S. Kennarp and B. B. Woopwarp, F.L.S., ete. 
Read 14th March, 1902. 
1. Lonpon WALL. 
Durine the year 1901 extensive excavations were made in Finsbury 
Circus and London Wall for the foundations of buildings for the 
London Wall Estate Company. Facilities were afforded us to visit 
and examine the sections, and we have secured numerous objects of 
interest. As is so often the case with Holocene deposits, the sections 
varied greatly, but there were always three well-marked layers. The 
lowest bed was Pleistocene gravel, 4 to 5 feet thick, resting on the 
London Clay. This was succeeded by an alluvial deposit of peaty clay 
from 4 to 8 feet thick, containing the remains of mollusca, as well as 
numerous objects belonging to the Roman period, such as broken 
bones, fragments of Samian ware and other pottery, besides large 
quantities of Ostrea edulis, Linn., Mytilus edulis, Linn., and Cardium 
edule, Linn.; whilst a few examples of Littorina littorea (Linn.), 
Buceinum undatum, Linn., and Dacoma baltica (Linn.) also occurred. 
The uppermost bed was ‘ made earth,’ consisting of the débris of the 
city: it included large quantities of old leather, medieval pottery, 
broken greybeards, ete., and was, in fact, a great dustbin accumulation. 
On the north-eastern side of the excavation, the lower part of the 
alluvial layer was evidently deposited by a large stream, in all 
probability the Wallbrook. Numerous traces of ‘ pile dwellings’ were 
disinterred in this spot. The non-marine mollusca were all obtained 
from the alluvial layer, of which the major part was accumulated 
during the Roman period, whilst the upper portion was deposited 
between the close of that period and Norman times. All the species 
occurred in the Roman layer; the later deposits, though yielding more 
examples, contained far fewer species. Helix aspersa occurred at the 
base, whilst one example of Vitrea cellaria was found still attached to 
part of a ‘ pile dwelling.’ 
