THE NON-MARINE MOLLUSCS OF ESSEX. 27
appearance under the microscope, with both low and high powers.
If possible, use a Camera Lucida ; you will then have your
drawing made to scale, and the spores can at any time be
accurately measured.
In conclusion, it will always give me pleasure to name
specimens or give any help I can to members of the Essex Field
Club who may wish to work at the group.
THE NON-MARINE MOLLUSCS OF ESSEX.
By WILFRED MARK WEBB, F.L.S., Editor of the Journal of Malacology.
[Read June 27th, 1896.]
UP to the present time, so far as the writer's knowledge goes,
no general catalogue of the land and freshwater mollusca
of Essex, dealing with that county as a whole, has been made
out.
Several important local lists from smaller districts are, how-
ever, to be found, chiefly in the publications of our Essex Field
Club. These, together with the notes and collections which
friends and correspondents have kindly put at the service of the
writer, and the specimens preserved in various museums, have
furnished the bulk of the material out of which the present paper
has been built up.
The following is a detailed list of authorities :—
A LIST OF AUTHORITIES FOR LOCALITIES AND OF COLLEC-
TIONS IN WHICH SPECIMENS ARE PRESERVED.
Adams, Lionel E.—A manuscript list of shells taken in 1881 and 1890, chiefly
in the neighbourhood of Halstead, Coggeshall and Colchester.
Bailey, George.—A manuscript list of shells from Finchingfield.
British Museum, Natural History.—(1.) A series of shells, chiefly from
Coggeshall, purchased in 1847 from Mr. Hall.§
British Museum, Natural History.—(2.) Collections of Pleistocene Mollusca
from :—Braintree; Clacton ; Copford (John Brown Collection) ; Grays ;
Kelvedon ; Rayne ; Roxwell (see Christy, Reginald) ; Walthamstow
(Joseph Wood Collection) ; Walton ; West Thurrock (see Woodward) ;
Witham.
Brown, John.—(1.) "Shell Marl at Copford," Journ. Geol. Soc, vol. viii.
(August, 1852), see also "Chelmsford Chronicle," September 22nd, 1843. For
corrected list, see specimens in British Museum.
§ For a note on Mr. Hall see E.N., vol. iv., p. 226.