On a snail, on ommatophore is a stalk with this at the end
The word snail is a common name for almost all members of the ... set of 
tentacles (called ommatophores or more informally 'eye stalks') which... [DOC] [TLE] Slug and Snail Anatomy - About Slugs [PAR] Slugs have evolved from snails and many species still retain a vestigial shell 
hidden under their ...