Definitions and Etymology

Snail: One of a group of terrestrial or aquatic molluscs belonging to the Class Gastropoda, typically having a spirally coiled shell, a broad retractile foot and a distinctive head. Sometimes the term ‘snail’ is applied exclusively to the land animal. Here, I have chosen the wider definition to include those marine and freshwater members of the group.

The word ‘snail’ derives from Old English snaegl, where snag- or sneg- means ‘to crawl’. The word is a diminutive form of Old English snaka, from which the word ‘snake’ also derives, meaning literally ‘a creeping thing’.

Slug: A land snail in which the shell is absent or rudimentary. Sea slugs also exist.

Molluscs: Soft-bodied creatures comprising chitons (Amphineura), snails and slugs (Gastropoda), tooth-shells (Scaphopoda), oysters and mussels (Lamellibranchs) as well as octopuses and squids (Cephalopoda). Sometimes spelled the American way, ‘mollusk’.

Conchologist: A student, and often a collector, of shells.

Malacologist: A student of molluscan anatomy, and hence the soft parts of the animal (from the Greek malacos meaning ‘soft’).