Plumularioid hydroids (Cnidaria: Hydrozoa) from off New Caledonia collected during KANACONO and KANADEEP expeditions of the French Tropical Deep-Sea Benthos Program Author Galea, Horia R. DE5AC672-0243-46F2-A910-AFF4E91A4C5D Hydrozoan Research Laboratory, 405 Chemin Les Gatiers, 83170 Tourves, France. Università degli Studi di Milano-Bicocca, Dipartimento di Scienze dell’Ambiente e della Terra, Piazza della Scienza 1, 20126 Milano, Italy. Università degli Studi di Milano-Bicocca, Marine and High Education (MaRHE) Center, 12030 Faafu Magoodhoo, Republic of the Maldives. horia.galea@gmail.com Author Maggioni, Davide 2A321960-E973-4742-B908-4394C0B9AF43 davide.maggioni@unimib.it text European Journal of Taxonomy 2020 2020-08-26 708 1 58 journal article 21028 10.5852/ejt.2020.708 0c523d70-0815-45f8-a69d-1698f78a0998 4011061 DDF28821-1A4A-4457-BB53-1696F3BFB7B2 Genus Actinopluma Galea gen. nov. urn:lsid:zoobank.org:act: 5CD7421D-F5D7-4AE5-8CC7-4C13AAD95F1D Type species Actinopluma mirifica Galea gen. et sp. nov. , designated herein (see below). Diagnosis Hydroids with upright, rigid, coplanar colonies with sparingly-branched stem; stem and branches fascicled. Main tube of the stem undivided, but equivalents of internodes with a lateral apophysis and a number of nematothecae above; apophyses alternate, coplanar, each with a mamelon, continued directly into a main hydrocladium; two accessory cladia, projecting outward and slightly upward, are given off laterally from below both sides of the mamelon; main hydrocladium divided into internodes with hydro- and nematothecae; accessory cladia shorter and thinner than main counterpart, generally composed of nematothecae-bearing internodes, occasionally with 1–2 intervening hydrothecate internodes distally. Hydrothecae cup-shaped, without associated nematothecae. Gonothecae unknown. Etymology From Ancient Greek ‘ ἀΚτίς ’, meaning ‘ray’, and Latin ‘ plūma ’, meaning ‘plume’, to describe the radiate appearance of this new hydroid genus. The gender is feminine. Remarks Based on morphological grounds alone, the absence of lateral nematothecae flanking the hydrotheca place this genus in the family Kirchenpaueriidae Stechow, 1921 . This allocation should be regarded as provisional, pending the collection of additional material suitable for molecular studies, expected to clarify unambiguously its systematic position. In having hydrocladia provided with two accessory appendages, the colonies of this so far monotypic genus somehow resemble macroscopically Oswaldella Stechow, 1919 , but in the latter, the hydrocladia branch dichotomously at the level of the proximalmost internode, the original cladium not extending beyond this internode ( Peña Cantero et al . 1997 ).