TABLE OF DISTRIBUTION. 



319 



Besides the species enumerated in the above list, lour 

 more occur in our upper tertiary strata, but are not now 

 found living in this country. One of them {Hydrobia 

 marginata) is aquatic and inhabits the South of Europe. 

 The other three (viz. Helix fruticum, H. incarnata, and 

 H. ruderata) are terrestrial and inhabit both the North 

 and South of Europe. H. fruticum and H. ruderata are 

 also Siberian species. 



It will be seen that, with only two exceptions (viz. 



