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LIST OF LAND AND FRESH-WATER MOLLUSCA
OCCURRING IN THE NEIGHBOURHOOD OF
BISHOP'S STORTFORD.
By EDWIN G. INGOLD.
[Read December 2nd, 1890].
THE following is a list of the Land and Fresh-water Shells which
occur in the immediate neighbourhood of Bishop's Stortford. The
number of species found at present is 59,—50 of which I have in my
own collection. Of the remaining nine species, eight have been dis-
covered by my friend, Mr. Frank Hughes, and the 59th (Unio
tumidus) was found by Mr. Walter Crouch, during the recent visit
of the Essex Field Club to Hatfield Forest.
As Bishop's Stortford is a border town, it may be well to mention
that several of these species have not actually been found in the
county of Essex. All the shells, however, named in the list occur
within three miles of the Essex boundary.
I have not collected the slugs, nor have I paid much attention to
the naming of varieties. For these, and other, reasons the following
list must be considered as preliminary to a more detailed account of
the mollusca of the district.
Species which are not in my own collection are marked with an
asterisk (*).
FRESH-WATER SHELLS.
Sphaerium corneum, L. River Stort; very common.
S. rivicola, Leach. River Stort; uncommon.
Pisidium amnicum, Mull. River Stort; common.
*P. fontinale, Drap. River Stort; uncommon.
Unio pictorum, L. River Stort, especially near Wallbury
Dells ; common.
*U. tumidus, Phil. Found by Mr. Crouch in the lake at
Hatfield Forest.
Anodonta cygnea, L. River Stort; frequent.
A. anatina, L. River Stort; common.
Paludina contecta, Millet. River Stort; common.
Bythinia tentaculata, L. River Stort; common.
B. leachii, Shepp. River Stort, near Spelbrook ; rare.
Valvata piscinalis, Mull. The "Town Meads" ditches,
Bishop's Stortford; common.
Planorbis albus, Mull. River Stort; frequent.
P. vortex, L. River Stort: frequent.