100 THE POST-PLIOCENE NON-MARINE MOLLUSCA OF ESSEX.
There are five new records :—Helicella caperata, Clausilia
rolphii, Vertigo edentula, V. moulinsiana, and Physa fontinalis. The
four latter species being all new for the Pleistocene of Essex.
The examples of Unio littoralis are said to have often had the
two valves united, and several pairs are known, one of which at
the Natural History Museum is remarkable for having traces of
its coloured periostracum preserved. It measures 69 x 47 x 28
mm. Numerous marine shells have also been recorded from this
locality, besides several species of Ostracoda and plants.
SHOEBURYNESS.
In the Prestwich Collection are numerous examples of
Corbicula fluminalis labelled Shoeburyness. That the locality is
correct there can be no doubt, as the late Professor Prestwich
mentions its occurrence there in one of his early papers. We
can obtain no further information about this deposit, and
we would call the attention of members of the Essex Field Club
to it, in order that it may be properly investigated.
HARWICH.
The only published list of shells from this locality is to be
found in the Geological Survey Memoir on Walton Naze and Harwich
(16), and contains fourteen names on the authority of a M.S.
by the late Dr. S. P. Woodward. So far as we can trace there
are only two collections extant—one at the Natural History
Museum, a part of the Lyell collection and containing ten species ;
while five species are in the Geological Society's Museum.
From these collections we are able to verify five records,
whilst seven species are new, and nine in the published list
are unrepresented. The new records are :—
Helix nemoralis Carychium minimum
Vertigo antivertigo Limnaea palustris
Vertigo angustior Paludestrina ventrosa
Succinea elegans.
The missing species are listed on the authority of the
recorder, but some changes in the nomenclature arc necessary :—
Bythinia ventricosa = Bythinia leachii, Clausilia nigricans = Clausilia
bidentata, Helix spinulosa = Acanthinula aculeata, Zonites rotundatus
= Pyramidula rotundata. Littorina sp. is also included in Dr.
Woodward's list : the presence cf which, with Paludestrina
ventrosa, clearly indicate slightly estuarine conditions. One of