NOTES ON THE LEA VALLEY. 79 



Although a small list, three species, Planovhis carinattis, 

 P. fontaniLs and Bithynia leachii, are unrecorded for this part of 

 the Lea Alluvium though it should be noted that only one other 

 series has been obtained.'^ 



All these forms are known from the Lea Alluvium at 

 Walthamstow, and are all univalves, a fact which, taken in 

 conjunction with their method of occurrence, lends great support 

 to the view that they did not live where they were found, but 

 are drifted shells. The gravel beneath the silt is undoubtedly of 

 Pleistocene age, and, in our opinion, represents a late stage of 

 that period when the land stood at a slightly higher altitude 

 relatively to the sea. This third terrace, as it has been called, 

 is as a rule unfossiliferous, though three species of mammalia 

 were found in it at Walthamstow in i86q, viz.: Elephas 

 pvimigenius, Blum. Bos pvimigenms Boj. and Cerviis stvongylocevos 

 Owen^. The last named is allied to the Red-deer, though much 

 larger. In the adjoining Thames Valley a fairly large fauna 

 has been found in the " Third Terrace." Flint implements 

 have been found occasionally in the Lea gravel, but all are 

 much abraded and rolled, and are undoubtedly derived from 

 higher levels, probably the High Terrace. In all likelihood it 

 is the higher level gravels that have furnished the materials of 

 which it is composed. 



The water level in the excavations was constant at 8 feet 6 

 inches from the surface, and great difficulty was experienced in 

 keeping the excavations dry. The enormous quantity of water 

 present may be gauged by the fact that from the hole sunk for 

 the engine bed lo feet by 14 feet and 14 feet deep, no less than 

 6,000 gallons per hour were pumped. 



We have to tender our best thanks to Mr. A. Kennard for a 

 knowledge of the sections, and it is entirely owing to the interest 

 and trouble that he took whilst the excavations were in progress 

 that this paper owes its existence. 



2A. S, Kinnard and B. B. Woodward " The| Post-Pliocene Non-Marine Mollusca of 

 Essex."— Essex Nat., Vol. x. (1897) p. 91 and Table. 



sWoodward, Henry "The ancient Fauna of Essex," Trans. Essex Field Club, 

 ^ol. iii., p. 7 



