The caudal mucous pit, or caudal mucous horn, is an anatomical structure on the tail end of the foot of various land snails and slugs, terrestrial pulmonate gastropod mollusks.
The function of this pit is the resorption of mucus when the gastropod is moving[1] (see also Muratov 1999).
An incorrect and yet often-used term for this structure is the "caudal gland".[1] This area also used to be referred to by the term "caudal pore".