47 
VI. 
A LIST OF' LAND AND DLESII WATER SHELLS 
FOUND IN NORFOLK. 
Ry John D. Riudgman, 
Head doth Janaanj, 1872. 
All the iiiollusca in the following li.st, with but two e.xceptions, 
have been foniul within a very short distance of the bonn- 
daries of tlie city of Norwich, and there is every ])robability that 
many others al.so might be fonml, if diligently sought for, in 
a more extended area. Hence it is very desirable that natu- 
ralists in other parts of the county should make themselves 
acquainted with the species in their own more immediate localities, 
as by these moans we should have a more complete list, and 
obtain a better knowledge of the extent of their distribution ; 
such assistance we have greatly felt the need of in compiling the 
following list. 
Norwich and its neighbourhood are very rich in species, the 
number of marsh ditches to be found close to the city form a per- 
fect paradise for the student of this branch of natural history. 
Yet this neighbourhood can scarcely be said to be more favourable 
in that respect than many other districts in the county, and as 
several of the species are extremely local, the contents of so small 
a field can hardly be deemed a foir average of the county, although 
a larger proportion has been obtained than might have been ex- 
pected, for out of 121 British species (not counting varieties), 
described in the “ British Conchology,” published in 1862, by Mr. 
John Gwyn Jeffreys, (the arrangement and nomenclature of which 
has been followed,) we have already found in Norfolk 84 — 38 
aquatic species out of 47, and 46 terrestrial out of 74. 
It is in autumn, when vegetation has just passed its full growth, 
and shews signs of coming winter, that we see snails in the greatest 
profusion ; every stream and pond swarms with the aquatic species ; 
