Our British Snails 13 



Let us imagine we are starting for an afternoon 

 sn ailing near London. Which way ? To Ox- 

 shot t ? To Caterham ? To the latter for choice, 

 since it is on the chalk, whereas the former is 



Dextral H. aspersa and H. pomatia. The right-hand 

 shell at the bottom shows the winter epiphragm of 

 H. pomatia. 



on the sand. Snails require lime to make shells, 

 and only on chalk or limestone will you find an 

 abundance. Here, too, as at Box Hill, we shall 



