354 PLEISTOCENE GEOLOGY OF THE THAMES VALLEY.
Association, by whom they were transferred to the National
Collection. It is known from the Pleistocene of the Thames
Valley at Ilford and Crayford.
Limax maximus, Linn. Two examples, one of which
has unfortunately been lost. This is a new record for the
Pleistocene of the Thames Valley, and it is only known in a
fossil state from the Ightham Fissure.
Vitrea nitidula, Drap., recorded by S. V. Wood. No
examples known.
Vitrea radiatula, Ald. On the authority of S. V. Wood.
Vitrea nitida, Mull. More than a dozen examples found,
most of which are immature.
Arion ater, Linn. Several calcareous granules occurred
which after a careful comparison with recent specimens we have
referred to this well-known slug. In this country it is only
known fossil from the Pleistocene of Ilford and the Holocene of
Newbury, but there is no doubt that it does occur in other
deposits as it is so easily overlooked or mistaken for a fragment
of quartz.
Pyramidula rotundata, Mull. Only one example, and
that immature, was found, but we are thus enabled to confirm
S. V. Wood's record.
Pyramidula ruderata, Stud. Recorded by S. V. Wood
who noted that it was common at this locality, but we have
failed to obtain any examples. It is known from Clacton,
Copford and Barnwell.
Punctum pygmaeum, Drap. Recorded by S. V. Wood.
Vallonia pulchella, Mull. Common.
Hygromia hispida, Linn. Common. As usual with this
polymorphic species there is considerable variation, several
examples being of the form named concinna by J. Gwyn Jeffreys
which is, however, the Linnean type of the species.
Helicigona arbustorum, Linn. Several fragments,
undoubtedly belonging to this species, enable us to confirm S. V.
Wood's record.