Redescription and systematic status of the Antarctic genus Abietinella Levinsen, 1913 (Lafoeidae,Hydrozoa, Cnidaria)

The Antarctic–Patagonian genus Abietinella, comprising two known species, Abietinella operculata (Jäderholm, ) and Abietinella grandis (Vanhöffen, ), is reviewed. The holotype of Abietinella operculata is fully redescribed, including morphometry and cnidome, unknown up to now. Its distinctive characters are the growth habit, hydrothecal shape and, most important, the presence of a dish‐shaped operculum attached to the adcauline side of the hydrothecal aperture. We corroborate its conspecificity with A. grandis and, therefore, the monotypic condition of Abietinella.