Priapulida, sometimes referred to as penis worms, is a phylum of unsegmented marine worms. The name of the phylum relates to the Greek god of fertility, because their general shape and their extensibl

Priapulus caudatus, known as the cactus worm, is a marine invertebrate belonging to the phylum Priapulida. It is a cylindrical, unsegmented worm which burrows in soft sediment on the seabed. It has a