78 THE NON-MARINE MOLLUSCS OF ESSEX.
B.—Finchingfield ; (Bailey) : River Colne, Halstead—with
anatina form ; (Adams) : River Chelmer, Felstead ;
(French) : River Blackwater, Coggeshall ; (Turner) :
Colchester—with anatina form ; (Laver, who thinks
anatina to be a variation, and suggests experiments) :
Markshall—and anatina form ; (Turner) : River Chelmer ;
(E.N., vol. v., p. 253) : Broomfield ; (E.N., vol. vii ,
p. 76) ; River Cann, Chignal; River Chelmer, Chelms-
ford ; Skreens Park, Widford Lake ; (Christy): River
Wid, Widford; (W.M.W) : Navestock Park—truncated
form and specimens 63/4 inches long; (Christy) : Clacton ;
(K., and W.).
C.—Saffron Walden; (S.W. Museum): Moat at Wimbish
Hall; (Christy): *River Stour ; (Laver Coll.).
Family—Cyrenidae.
Genus—CORBICULA, Megerle von Muhlfeldt, 1861.
[Corbicula fluminalis, Muller.] Extinct in Britain.
A.—Ilford ; Grays; (British Museum).
B.—Clacton (K. and W. after S. V. Wood).
Genus—SPHAERIUM, Scopoli, 1777.
Sphaerium rivicola, Leach.
A.—River Stort ; (Ingold).
Sphaerium corneum, Linne.
A.—River Stort ; (Ingold) : Hatfield Forest ; (E.N., vol. iv.,
p. 223) : River Roding, Abridge ; (Newstead) : River
Lea, Chingford ; (C.S.R., Scharff) : River Roding,
Woodford; (C.S.R., Oldham): Barkingside; Wan-
stead ; Leytonstone ; Whips Cross ; Walthamstow ;
East Ham ; (Crouch) : *Tilbury Marshes ; (Jenkins) :
Canning Town ; (K. and W.) : Ilford ; (Woodward after
Dawkins) : Walthamstow ; (British Museum) : Docks;
Grays; Tilbury; (British Museum).
B.—Finchingfield; (Bailey): River Colne, Halstead; (Adams) :
Beaumont ; (Sheppard Collection) : River Chelmer,
Felstead ; (French) : Coggeshall ; (British Museum) :
*Kelvedon; ( ? ): Little Tey; (Adams); Colchester;
(Laver): River Chelmer ; (E.N., vol. v., p. 253) ; Broom-
field ; (E.N., vol. vii., p. 76) : Chelmsford—yellow
variation; (Christy): River Cann,Chelmsford; (W.M.W.):
*Clacton; (Webb, 4): Witham; (British Museum). [‡Chignal
recorded, but no specimens in Christy Coll.]