Wikipedia
Phyllophoridae
Phyllophoridae is a family of sea cucumbers, marine invertebrates with elongated bodies, leathery skins and feeding tentacles.
Members of the family are characterised by a complex ring of calcareous ossicles arranged in a tube, making a mosaic pattern. The tentacles number ten to twenty-five. Some members have spindle-shaped bodies whilst others are buried in the substrate and adopt a U-shaped form.