214 THE POST-PLIOCENE NON-MARINE MOLLUSCA 



Valvata piscinalis (Miill.) 



,, cristata Miill. 

 Bythinia tentacnlata (Linn.) 

 Corbicula finminalis (Miill.) 

 Anodonta cygncra (Linn.) 

 Spho'i'ium coyneiuii (Linn.) 

 Pisidiitm aiiiiiiciiiii (Miill.) 



,, astavtoides (Sandb.) 



,, pusillum (Gniel.) 



From the adjacent Upball Pit forty-six species have been 

 obtained, for in addition to the thirty-nine species recorded by 

 J. P. Johnson and G. White in the last part of the Essex 

 Naturalist {ante pp. 157-160), seven other forms are known, 

 viz. : — 



Hygi'omia kispida (Linn.) 



Helicigona avhustovntn (Linn.) 



Snccinea piitvis (Linn.) 



Plaiioihis alhus (iVIiill.) 

 ,, liiieatus (Walk.) 



Bythima leachii (Shep.) 



Unio pictonim (Linn.) 



The two lists thus shewing a total of fifty-seven species, 

 being the largest number known from any Pleistocene or Holo- 

 cene deposit with the exception of Copford and Barnwell. It is 

 indeed worthy of note that in 1890, when the shells from Ilford 

 were first listed by one of us,'' only twenty species were known, 

 though ten others were listed on the authority of the various 

 recorders. In 1897, as a result of Dr. Corner's labours, we were 

 able to list thirty-seven forms from known specimens and nine on 

 authority, Avhilst the last three years' work of Mr. Hinton, Mr. 

 Johnston, and Mr. White has raised the total to fifty-seven known 

 species. There still remain three records to be confirmed, viz. : — 



Pyramidida yudevata (Stud.) 

 Vitvca fidva (Miill.) 

 Planoi'his coniciis (Linn.) 



Of these there is one form which we strongly desire to be 

 confirmed, Pyvamidula riiderata. The record is on the authority 

 of Dr. J. Gwyn Jeffreys, who in i86g, during the discussion 

 following a paper by Professor W. Boyd Dawkins " On the 



2 B. B. Woodward. — " On the Pleistocene Non-Marine Molhisca of the London 

 District." Proc.Gco!. .-Issor., vol. xi., pp. 335-388. 



