13 



THE NON-MARINE MOLLUSCA OF THE RIVER 

 LEA ALLUVIUM AT WALTHAMSTOW, 

 ESSEX. 



By A. S. KENNARD, M. Malac. Soc, and B. B. WOODWARD, F.L.S., F.G.S. 



[Read December 6th, 1902.] 



THE extensive excavations for new reservoirs for the East 

 London Water Company that have lately been made in 

 the Lea Valley, near Walthamstow, furnished a magnificent 

 opportunity for collecting from tlie Holocene deposits, which are 

 only exposed in chance excavations. Application was made to 

 the contractors, Messrs. S. Pearson and Sons, for permission to 

 visit the works, and this was at once granted. We would take 

 this opportunity of tlic nking them and the following gentlemen 



»>. . — 



Mmmwii^^ 



- ^ ■ • i^: "Xit^^^^-^i::^^■ > ■ .:'^-^^^^^^ '^^^r^v^^SiiSlL^'^"!^ 



1<'IG. 1. — SECTION IN NEAV RESERVOIRS, WALTHAMSTOW, ABOUT lOO YARDS 



Showing lenticular bed of Shell-marl resting on Peat, and covered by the Clay forming 

 the surface. Gravel at the base. (T. V. Holmes.) 



for facilities in visiting the sections, and for other assistance : — 

 Mr. W. Cole, Mr. W. Whitaker, F.R.S., Mr. C. W'. Sharrock, 

 Colonel Bryan, Mr. J. P. Johnson, and especially Mr. W. Traill. 

 Repeated visits have been made, and an immense amount of 

 material has passed through our hands. The sections have 

 already been described by Mr. T. V. Holmes,^ and as may be 

 seen by reference to this paper, a twofold division of the beds is 

 always present, an upper peaty or loamy bed sometimes con- 

 taining Shell-marl and a lower bed of Gravel. 



The gravel contained no fossils except where it was obviously 

 re-deposited. There can be no doubt that the peaty beds,. 

 which varied from 3 to 10 feet in thickness, represent the whole 

 of the Holocene deposits, and are the equivalent of the 60 feet of 

 alluvium met with in the Thames valley at Tilbury, whilst the 

 bottom gravel may be correlated with the third terrace of the 



I Consult " Geological Notes on the New Reservoirs in the Valley of the Lea, near 

 VValthamstow." A". A". Vol. XII., pp. 1-16, and "Additional Notes" on the same in E.N.. 

 \o\. XII., pp., 224-231. 



