edible snail    The word snail is a common name that can be used
for almost all members of the molluscan class Gastropoda which
have coiled shells in the adult stage. (Those snails which do
not have a shell or only a very small shell are usually called
slugs. Snails which have a broadly conical shell which is not
coiled, or appears not to be coiled, are most often known as
limpets.)  The class of Gastropoda (the snails and slugs) is
second only to the insects in terms of total number of species.
Snails are extraordinarily diverse in habitat, form, behavior,
and anatomy, and therefore what is true of one snail species may
not at all be true of another.  Snails can be found in a wide
range of different environments from ditches to deserts to the
abyssal depths of the sea. The great majority of snail species
are marine. Many others are terrestrial, and numerous kinds can
be found in fresh water, and even brackish water. Many snails
are herbivorous, though a few land species and many marine
species are omnivores