of the District around Colchester. 98
Donyland Wood, where the spring scarcely gave enough
water to cover the shell. This is one of the molluscs which
aestivates early, very frequently disappearing early in March.
Ancylus fluviatilis, Mull.—I have only found this mollusc
in the stream near Kingsford, Stanway, and there sparingly,
adhering to stones.
A. lacustris, Linn.—Frequent in the Stour and Colne on
water-lilies and other plants. The dead shells are very
numerous in the Stour at Wormingford, and are also plentiful
at Copford in the classic Shell Marl.
Limacidae .
Arion ater, Linn.—Common everywhere.
A. hortensis, Linn.—Common everywhere.
Limax flavus, Linn.—Common everywhere.
L. agrestis, Linn.—A common pest.
L. maximus, Linn.—Frequent in ashpits in the town, as
well as commonly in woods and damp places.
Helicidae.
Succinea putris, Linn.—Frequent in wet spots by the
rivers and brooks. In the water-furrows of the meadows
near New Bridge, I find a very small variety, with a shell, in
proportion to its size, thicker than usual; this may be Var.
subglobosa, Jeffreys. It has one peculiar habit, being rarely
found otherwise than submerged. In the spots where I find
this variety, I never find the normal form.
S. elegans, Risso.—Common on duckweed in the ditches
of the meadows close to the town ; its blackness makes it
very prominent.
Vitrina pellucida, Mull.—Frequent under stones, wood,
or anything which retains moisture, the dead shells being
much more numerous than living ones.
Zonites cellarius, Mull.—Frequent in suitable spots. I
have found it in damp places at the foot of the cliffs at
Walton-on-the-Naze, of a dark horn colour ; but in some
cellars at Shrub End, near Colchester, the shells are very
large, flat, and almost white in colour.