356 PLEISTOCENE GEOLOGY OF THE THAMES VALLEY. 



ccllection). Lately, however, it has been found in a Holocene 

 rainwash at Reigate, and now that it has been proved to occur 

 in the Pleistocene it must be considered an ancient inhabitant 

 and not a recent introduction, a conclusion which is in accord- 

 ance with its discontinuous distribution in England. 



Clausilia bidentata, Strom. Several fragments. Hitherto 

 unrecorded from Graj'S. 



Succinea putris, Linn. Recorded by the late Professor 

 John Morris. 



Succinea elegans, Risso. Several examples. A new 

 record for Grays. 



Carychium minimuni, Miill. Two imperfect examples, 

 thus confirming the record of this species by Prof. Morris. In 

 the Pleistocene of the Thames Valley it is only known from N.E. 

 London, the Admiralty section and Ilford. 



Ancylus fluviatilis, Miill. Common. 



Velletia lacustris, Miill. Common. (This species is 

 generally known as V. lacustris, Linn., but it is not Linne's 

 species which is the shell known as Ancylus fluviatilis, Miill. 

 Hence to avoid confusion it is better to ignore Linne's name). 



Limnaea auricularia, Linn. A single example. 



Limnaea pereger, Miill. Common. 



Limnsea palustris, Miill. Common. 



Limnaea truncatula, Miill. Common. 



Limnaea stagnalis, Linn. A single apical fragment 

 only. Recorded by S. W. Wood, but hitherto no example 

 known. 



Planorbis corneus, Linn. Recorded by S. V. Wood. 



Planorbis albus, Miill. Common. 



Planorbis glaber, Jeff. Two examples, thus enabling us 

 to confirm S. V. Wood's record. 



Planorbis nautileus, Linn. Recorded by S. V. Wood. 



Planorbis carinatus, Miill, Listed by Prof. Morris. 

 Perhaps an error for the next species. 



Planorbis marginatus, Drap. Several examples. 



