THE NON-MARINE MOLLUSCS OF ESSEX.
79
C.—Saffron Walden ; (S.W. Museum) : Wrabness ; (Shep-
pard and Collection).
Sphaerium ovale, Ferussac.
A.—Woodford ; (E.N., vol. iii., p. 39, Sauze).
Sphaerium lacustre, Muller.
A.—Tilbury Marshes ; (Jenkins).
B.—Finchingfield ; (Bailey) : Little Tey ; (Adams) ; Colches-
ter ; (British Museum and Laver) : Ardleigh Wick ;
(Laver Coll.) : Chelmsford ; (Christy).
C.—Saffron Walden ; (S.W. Museum).
Genus—PISIDIUM, C. Pfeiffer, 1821.
Pisidium amnicum, Muller.
A.—River Stort ; (Ingold) : River Roding, Woodford ; C.S.R.,
Oldham) ; Fern Hall ; Barking Side ; Wanstead Basin ;
(Crouch) : Canning Town ; (K. and W.) : Ilford ; Waltham-
stow : Docks ; Grays ; (British Museum).
B.—Halstead ; (Adams) : Finchingfield ; (Bailey) : River
Chelmer, Felstead ; (French) : Coggeshall ; (British
Museum) : Colchester ; (Laver) : River Chelmer and
Beeleigh Mill ; (E.N., vol. v., p. 252) : Broomfield ;
(E.N., vol. vii., p. 76) : River Cann, Chelmsford ;
(W.M.W.): *Clacton ; (British Museum).
C.—Saffron Walden ; (S.W. Museum) : Ramsey ; Wrab-
ness ; (Sheppard Collection).
[Pisidium astartoides, Sandberger.] Extinct in Britain.
A.—Ilford ; (K. and W.) : Grays ; (British Museum).
B.—*Clacton ; (British Museum).
Pisidium pusillum, Gmelin.
A.—Fern Hall; (Crouch) : Ilford ; Canning Town ; Lea Valley ;
(K. and W.) : Grays ; (Woodward after S. V. Wood).
B.—River Chelmer, Felstead ; (French): Coggeshall ; (British
Museum) : Colchester ; (Laver) : [Felstead ; French] :
*Copford ; (British Museum) : Clacton ; (K. and W.
after J. Brown) ; Shalford ; (W.M.W.) : *Chignal ;
(Christy, 3, recorded as P. nitidum) : Roxwell ; (R. Christy).
C.—Saffron Walden ; (S.W. Museum) : River Stour ; (King) ;
Harwich (K. and W. after G. P. Woodward).
Pisidium nitidum, Jenyns.
B.—Colchester ; (Laver) : ‡Chignal specimens were pusillum.