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, Aid. On the authority of S. V. Wood. 



Vitrea nitida, Miill. 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, MiiU. 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. 



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