Publication Abstract

The hydrozoan genus material. The taxon includes four valid species: and southwest Pacific oceans; the type species, Pacific oceans; and Although type specimens of Zyzzyzus is revised based on reexaminations of all available type specimens and on additionalZyzzyzus spongicolus (von Lendenfeld, 1884), from the eastern IndianZ. warreni Calder, 1988, from the Atlantic, western Indian, and westernZ. floridanus Petersen, 1990 and Z. robustus Petersen, 1990, both from the northwest Atlantic.Z. calderi Petersen, 1990 could not be located, it has been assigned here to the synonymy of Z. warreni canals, and in external morphology of the hydrocaulus and hydrorhiza. A sixth nominal species (because of similarities between the two in nematocyst dimensions, in number and structure of endodermalCorymorpha iyoensis Yamada, 1958) has on one occasion been assigned to the genus, but detailed studies of the type material are needed to resolve its taxonomic affinities.