Identifying terrestrial gastropods

Shell Classification

How do you know if you truly have a snail or a slug?

Gastropods that possess an obvious shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
are termed snails, whereas gastropods that appear to lack an obvious shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
are termed slugs. In the case of semi-slugs it may be debatable whether the animal should be considered a snail or a slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
. The entitiesEntities:
See also entity
included in this tool are divided into two major categories (snails and slugs) to reduce ambiguity and to allow users to quickly and more efficiently navigate through the key.

Shell Shell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
present:

Shell Shell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
obvious with definite coiling and animal may be able to retract into it.

Shell Shell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
absent:

Shell Shell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
very reduced or internal and if present, it has no definite coiling. If the shellShell:
A hard, inflexible, calcareous or chitinous structure that vary in size and may either completely encasing the animal, covering some part of it or be internal.
is partially external, it is usually small and is located on the posteriorPosterior:
Directional term: the rear or tail end of an animal.
end of the mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
(see image below, far right).