About a score of species of non-marine Gastropoda which formerly occurred in the British Isles are still to be found living on the Continent of Europe or in Asia.
Theodoxus cantianus Kennard & Woodward, M. Pleistocene, which Dr. Kerney informs me is synonymous with T. serratiliniformis Geyer, bears a close resemblance to T. prevostianus (Pfeiffer), inhabiting thermal waters in Austria, Hungary and Croatia.
Valvata antiqua Morris, M. Pleistocene, is regarded as a subspecies of V. piscinalis (MUller) by Ehrmann, who gives its Continental distribution and figures it (1933, pi. 9, fig. 123).
Valvata (Borysthenia) naticina Menke, M. Pleistocene: Germany to S. W. Russia; figured in Ehrmann, 1933, pi. 9, fig. 121. (Borysthenes is the R. Dnieper or Dnepr, Ukraine.)
Acicula (Flatyla) polita (Hartmann), U. Pleistocene: France and Denmark to Carpathians and Estonia. See J. Letchworth Nat. Soc. No. 5, P- k (19^5)5 Kerney, 1959, 327, figs. 1, 1a. Related to A. subpolita (Gottschick) from U. Miocene (Sarmatian) of WUrttemberg. A. (Hyalacme) diluviana Hocker occurs in the same deposit near Hitchin as A. polita. (The derivation of Platyla Moquin-Tandon is obscure: if from Gk., it could mean "flat wood", which seems nonsense.)
Paladilhia (Belgrandia) marginata (Michaud), M. & U. Pleistocene: foot¬hills of Pyrenees and Alps, N. Spain, S. France, N. Italy; figured by Sparks, 1957, pi. 3, figs. h-1.
Lithoglyphus fuscus (Pfeiffer), Weybourne Crag: Danube. The closely related or conspecific L. naticoides (Pfeiffer) extends from S. W. Russia to Germany and Latvia, and within recent times has spread to Holland, Belgium and N. France. Figured in Germain, 1931, pl. 18, figs. 514, 515, 517.
(Carychium ovatum Sandberger is synonymous with C. minimum Muller.)
Azeca menkeana (Pfeiffer), M. & U. Pleistocene, is probably a subspecies of A. goodalli (Ferussac). France, Denmark, Germany. See Kerney, 1959, 332, figs. 7, 8.
Columella columella (Benz), U. Pleistocene, is probably a subspecies of C. edentula (Drap.). Arctic-Alpine. Figures: Ehrmann, 1933, pl 1, fig. 15; Geol. Mag. 94, pi. 7, figs. j-k; Kerney, 1963, pi.11, figs. f, g.
Vallonia enniensis (Gredler), Cromerian to U. Pleistocene: synonymous with V. costellata (Braun) Sandberger and probably
V. tenuilimbata (Sandberger); may be a variety of V. pulchella (Muller). Figures: Sparks, 1953b, 112, figs. e-h; 1957, pi. 3, figs. m-o.
Vallonia tenuilabris (Braun), U. Pleistocene: Siberia and possibly E. Turkistan and N. China. Sparks, 1953b, 112, figs. a-d.
Lauria sempronii (Charpentier), Holocene: S. Europe, Pyrenees to Caucasus, mainly montane. Kerney, 1957, J. Conch. 24:183.
Clausilia parvula (Studer) Ferussac, U. Pleistocene: Central Europe. Figures: Germain, 1931 pi. 13 fig- 370; Ehrmann, 1933 P 68, fig. 42.
Clausilia pumila Pfeiffer, M. & U. Pleistocene: Central Europe. Ehrmann, 1933 pi. 2, fig. 34.
(Clausilia cruciata Studer was recorded in error (Kerney, 1959, 333))
Clausilia (Plicaphora) ventricosa (Draparnaud), M. & U. Pleistocene: Central Europe. Figures: Germain, 1931 pl. 13 figs. 393, 394; Ehrmann, 1933, pi. 2, fig. 35.
Laminifera (Neniatlanta) pauli (Mabille), M. Pleistocene: Pyrenees. Kerney, 1959* figs. 10, 11; Germain, 1931 pl. 131 figs. 389* 390.
Graciliaria (Ruthenica) filograna (Rossmassler), M. Pleistocene:
Central and E. Europe. Kerney, 1959* fig* 6.
(Lindholmiola lens (Ferussac): the record from the Waltonian Crag (Geol.~Mag. (3) 1:2627 is too improbable to be accepted.)
(Hygromia (Zenobiella) rubiginosa (Schmidt): the record from the Norwich Crag (Proc. Malac. Soc. Lond. 3=191) is probably based on incorrect determination.!
Hygromia (Monachoides) incarnata (Muller), Waltonian Crag: Central Europe. Germain, 1931 pi. 5 figs. 118, 119.
Helicella (Xeroplexa) geyeri (Soos), Norwich Crag and U. Pleistocene: Germany, Switzerland, Belgium and probably E. France. Sparks, 1953a;
Kerney, 1963, pi. 12, figs. d-f.
Helicella (Helicopsis) striata (Muller), U. Pleistocene and Holocene: Central Europe. Sparks, 1953a*
Discus ruderatus (Ferussac), Cromerian to Holocene: Central Europe, Norway to Spain, N. Italy and Transcaucasia; N. Asia to Kamchatka and Japan. Taylor's Monograph 3, fig 250.
Nesovitrea (Perpolita) petronella (L. Pfeiffer), Early Holocene:
Central Europe, north to Norway and Finland; Siberia, Manchuria. Figure: Arch. Moll. 89:220.
Vitrina (Seniilimax) semilimax (Ferussac), Cromerian to U. Pleistocene: Alpine and Central Europe, S.W. to Pyrenees. Kerney, 1959* 334.
References
Ehrmann, F., 1933* Die Tierwelt Mitteleuropas. Mollusken (Weichtiere). Germain, L., 1931. Faune de France, 22. Mollusques terrestres et fluvia- tiles, 2.
Kerney, M. P., 1959. An Interglacial Tufa near Hitchin, Hertfordshire.
Proc. Geol. Assoc. 70: 322-337*
Kerney, M. P., 1963. Late-Glacial deposits on the Chalk of south-east England. Phil. Trans. Roy. Soc. (B) 246: 203-25*+, pi. 11-14.
Sparks, B. V/., 1953a* The former occurrence of both Helicella striata (Muller) and H. geyeri (Soos) in England. J. Conch. 23: 372-378.
Sparks, B. IV., 1953b. Fossil and Recent English species of Valionia.
Proc. Malac. Soc. Lond. 30: 110-121.
Sparks, B. W., 1957* The non-marine Mollusca of the Interglacial deposits at Bobbitshole, Ipswich. Phil. Trans. Roy. Soc. (B) 241:33-44, pis. 3* 4.
Acknowledgment
Dr. M. P. Kerney has kindly read this article and made some additions and emendations.
A. E. Ellis