66 



ON THE SPECIFIC IDENTITY OF VIVIPARA BILUVIANA, KUNTH, 

 AND VIVIPARA CLACTONENSIS, S. V. WOOD. 



By A. S. Kennard and B. B. Woodward, F.L.S. 



Read 8fh January, 1904. 



In 1878 the late Mr. S. V. Wood provisionally described and figured 

 two shells from the Pleistocene of Clacton, Essex, as Paludina 

 Clactonensis,^ but he pointed out that a shell from the Pleistocene of 

 Templehof, near Berlin, F. diluviana, Kunth,'* greatly resembled the 

 Clacton examples, and might prove to be identical. It may be noted 

 that the Clacton shells, which wei'e found by the Kev. 0. Fisher, had 

 previously been recorded as Paludina lenta? 



The late Professor C. L. F. Sandberger, however, considered that 

 the two forms were distinct, and that the nearest allies to the Clacton 

 shell were P. Lenzi, Moisisovicst, and JBrMsinai, Neumayr, from the 

 Congeria beds of Sclavonia.* 



A third example was found at Clacton by Mr. A. Bell, and when in 

 1897 we revised the Clacton records, these were the only examples 

 we could trace.' Since then the Eev. J. W. Kenworthy presented to 

 the Essex Field Club a series of non-marine mollusca from Clacton, 

 which had been obtained by himself some years previously. This 

 collection contained a fine series of Vivipara Clactonensis, which was 

 noted by Mr. W. M. Webb in 1902,« whilst in 1901 we recorded the 

 occurrence of this form in the Pleistocene gravel at Swanscomb, 

 Kent.'' Last year a series of Pleistocene mollusca was sent to one of 

 us by Dr. E. W. Wiist, of Halle, and on comparing the examples of 

 V. diluviana from several German localities with the Clacton and 

 Swanscomb shells, it was at once seen that they were identical, in 

 which opinion we have the support of Dr. Wiist, and since diluviana, 

 Kunth, has priority by many years, Clactonensis must be considered 

 a synonym for that form. V. diluviana is apparently not a wideh' 

 distributed form on the Continent, but it is known from Templehof 

 bei Berlin, Baumgartenbriich bei Potsdam, Latdorf bei Magdeburg, 

 Sperenberg, and several localities near Halle. In size the Swanscomb 



^ S. V. Wood, " Crag Mollusca," '2nd supplement, 1878, p. 69, and tab. i, figs. 4«, b. 



* Zeitschrift Deutsch. Geol. Gesellschaft, Berlin, 1865, tab. vii, fig. 8. 

 ^ S. V. Wood, jun. : Geol. Mag. 1866, p. 350. 



* Palseontographica, Bd. xxvii, p. 98. 



* A. S. Kennard & B. B. Woodward, "The Post-Pliocene Non-Marine Mollusca of 



Essex": Essex Nat., vol. x, pp. 97-100. 



* W. M. Webb, "Pleistocene Non-Marine Mollusca from Clacton-on-Sea" : Essex 



Nat., vol. vi, pp. 225-227. 

 ' A. S. Kennard & B. B. Woodward, "The Post-Pliocene Non-Marine Mollusca of 

 the South of England" : Proc. Geol. Assoc, 1901, vol. xvii, pp. 238-9. 



