Five species of hydroids formerly thought to be rare are redescribed and their ecology discussed. These are a hydroid doubtfully assigned to Clytia hemisphaerica Linnaeus, 1767, Silicularia undulata (Mulder & Trebilcock, 1914), Thyroscyphus macrocytharus (Lamouroux, 1824), Clytia paulensis (Vanhoffen, 1910), and the hydroid and medusa stages of Phialella quadrata (Forbes, 1848). Two other species, Lafoeina amirantensis (Millard & Bouillon, 1973) and Aglaophenia postdentata Billard, 1913 are new records for Australia.Descriptors: CLYTIA HEMISPHAERICA; SILICULARIA UNDULATA; THYROSCYPHUS MACROCYTHARUS; CLYTIA PAULENSIS; PHIALELLA QUADRATA; LAFOEINA AMIRANTENSIS new record; AGLAOPHENIA POSTDENTATA new record; figs 1-4.
Systematics, Taxonomy
Zoogeography, Biogeography (generalities), Geographic distribution