The European athecate hydroids and their medusae (Hydrozoa, cnidaria): Filifera part 3

This study reviews all European hydroids belonging to the filiferan families Hydractiniidae, Rhysiidae, and Stylasteridae. Stylasterids are treated only summarily because a recent, exhaustive monograph is available. Stylactaria claviformis Bouillon, 1965 and Hydractinia calderi Bouillon, Medel, & Pena Cantero, 1997 are both regarded as junior synonyms of Hydractinia proboscidea (Hincks, 1868). Podocoryna corii Stechow, 1929 is regarded as a new junior synonym of H. borealis. Cytaeandrea polystyla Haeckel, 1879 is perhaps a synonym of Turritopsis polycirrha (Keferstein, 1862). Hydractinia areolata Alder, 1862 is selected as type species for the genus Cytaeandra Haeckel, 1879. Clavopsis adriatica Graeffe, 1883a is an indeterminate species, perhaps belonging to Turritopsis dohmii (Weismann, 1883).