There has been some confusion over the past 150 years or so concerning the correct combination to be applied to the single species of hydroid variously known as Arum cocksi, Myriothela phrygia and M. cocksi. The correct binominal would seem to be Candelabrum phrygium, a combination first used by de Blainville (1830) but hardly used since. An attempt by Stechow (1921, 1922, 1923) to re-introduce this combination has apparently been unsuccessful. The synonymy relevant to the genus name is as follows. To avoid repetition some information more relevant to the nomenclature of the species name is also included here.