SEA LILY

any crinoid marine invertebrate (phylum Echinodermata) in which the adult is fixed to the sea bottom by a stalk. The stalk is surmounted by a bulbous body with frondlike tentacles; i.e., the animal resembles a plant. The stem consists of limy disks, and the body has an internal skeleton of close-fitting limy plates. Sea lilies occur chiefly in deep waters, where they feed on detritus. Of 80 living species none more than 60 cm (24 inches) tallmany belong to the genus Metacrinus, distributed from Japan to Australia. A common West Indies species is Neocrinus decorus. More than 5,000 extinct speciessome 20 m (65 feet) longare known. They are important index fossils of the Paleozoic Era (from 540 to 245 million years ago).