PLATE V. 
Ponpb Swnaius (Genus Limneda). 
1, LZ. stagnalis, Linné, central shell immature; 2, Z. feregra, Miiller; 3, 4, 
L. auricularia, Linné ; 5, £. palustres, Muller; 6; 22 elabra, Muller;) 7, 2: 
truncatula, Miiller, the secondary host of the ‘‘ liver fluke” of sheep. 
The differences, apart from size, are slight variations in the spire and aperture, the family 
likeness is unmistakable. There is phylogenetic evidence that Limnea peregra (by far the 
commonest species) is the ancestral form from which all the others have been derived. 
All were taken in the neighbourhood of Berrow. 
From a photograph by Dr. Roger Hutchinson, Haslemere. 
