317 
NOTES ON THE PLEISTOCENE NON-MARINE MOLLUSCA AT 
PORTLAND BILL; AND ON HOLOCENE NON - MARINE 
MOLLUSCA FROM (1) WEST HARNHAM, WILTS ; (2) HARLTON, 
CAMBRIDGESHIRE; (3) THE DOWN ABOVE DURDLE BARN 
DOOR, DORSET; AND (4) FOLKESTONE. 
By the Rev. R. Asntneron Butten, F.L.S., etc. 
Read 13th Mareh, 1903. 
I. Portrnanp Brit. 
Dorine a visit to Portland Bill on June 23rd, 1902, I was able to add 
one more definite species to the mollusca of the late Pleistocene deposit 
near the Bill. Two specimens of Helix nemoralis were found. 
Hitherto the Heliz-shells have not been specifically identifiable. 
Limnea pereger and Limnea truncatula were also met with on this 
occasion in greater abundance. Numerically the relative quantities 
obtained have been as follows :— 
Species. 1894. | 1900. 1902. | Total. 
Helicella vtala (Linn.).........+-. — 2 9 11 
Hygromia hispida (Linn.). ...... 1 —- — 1 
Hygromia rufescens (Penn.) ...) = 10 16 26 
Vallonia pulchella (Mill.)....... 5 _ 1 6 
Helix nemorals, Linn. ......... — — 2 2 
SIG 125 ASWod ste fe easicsees ee on: — 1 1 2 
Pupa muscorum (Linn.).......... 56 28 136 220 
Suceinea oblonga, Drap. ......... 41 9 14 64 
Limnea pereger (Miill.).......... 4 22 29 55 
Limnea truncatula (Mill.)...... — 16 44 60 
Pomatias elegans (Miill.)  ...-.. 1 — — 1 
ESI CUNE STDs: ceewnevesinewseatioses.c| 1 — — 1 
The curious feature of the above list (for 1902) is the abundance 
of three forms, P. muscorum, Limnea pereger, and L. truncatula, the 
diminished number of S. oblonga, and the comparative scarcity of 
such generally abundant Pleistocene forms as Helix nemoralis and 
Pomatias elegans. But, as Sir Joseph Prestwich used to say, 
‘Quaternary geology has many blanks.” 
The records for 1894 and 1900 were published in the Geological 
Magazine, pp. 431 and 286 of the respective years. The pale 
single-banded variety of H. nemoralis represented at Portland Bill 
is still abundant at White Nore on the Dorset coast. Very large 
specimens also occur at Harlyn Bay, Cornwall, in the kitchen midden 
just outside the late Celtic cemetery, and Dr Scharff has recently 
sent me three fine and massive specimens from Dog’s Bay, Connemara. 
