Caudal mucous pit on some species included: Caudal mucous pit 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 (see also Muratov 1999). An incorrect and yet often-used term for this structure is the "caudal gland". This area also used to be referred to by the term "caudal pore". Families of snails and slug where a caudal mucous pit exists in every species included: Families/subfamilies where is caudal
Melanocetus murrayi fish, and the bioluminescent esca on the tip is oval, sometimes with a raised crest at the back. The second dorsal fin has 12 to 14 soft rays, the anal fin has 3 to 4, the pectoral fin 15 to 18 and the caudal fin 9. Females grow to a length of about and males to . "M. murrayi" has a cosmopolitan distribution in tropical to temperate parts of the world's oceans, between about 64°N and 43°S, and at depths from the surface down to over , although most of the individuals recovered have been at greater depths than .