STAR FISH ON A STEM

New Zealand Times, Volume XXXII, Issue 7078, 16 March 1910, Page 9

STAR FISH ON A STEM

A very.Jnteregta'ng',,-enb-pliyl'am-.of i 'tli«echiiioderia^."is' 3awwii -ag ,':J?elma,tozoa, characterised * by ; beiag fixed by a stem. The survivors of the group are few in number, and confined to, one, class, the Grmoidaa; but formerly; they were very, abundant,-and attained a remarkable development; eo that four classes are necessary to contain: the 'fossil forms. Of the ccinoids there are 12 'recant genera, of which eight retain the stalk throughout life, the remaining four, losing it in the adult staffed The stalked'forms are confined to considerable ■, depths, and long escaped notice, as'did'also the temporary stalks,;-o£-.the early stages of the stalkless The long- stem- is best seen .in the Peatacrinidae, our' knowledge of which ..has: a curious ■ history.... Fossil forms were known long before the living animal was" found; as far back,! indeed, as the seventeenth- eenturv. Some of these had stalks' 18ft long. , Tho iossU remains are' the hartl internal ekeloton or carbonate of lime, and they were long known<ae stone-lilies.- In the eighteenth century., a living •specimen ■ was- brought from, the West Indies and,described as a sea-palm .tree. Many, hundreds of extinct; forms are known, particularly in Silurian, Devonian., and .. carboniferous rooks. ' In 1836 Vaughan Thompson found a small Pentacxjnus attached 'by a minute stalk, which later on shrivelled up, leaving a free swimimng'an>;<tal, readily recognised as the common feather star. The Royal- Society- refused - to publish] .this incredible observation, but its truth to soon demonstrated. I/ittle "fttoiielilies", were, in, fact, abundant in -European, waters all the time naturalists were fn hot dispute about theiu.' .