The International Commission on Zoological Nomenclature has not conserved the generic name Lychnorhiza Haeckel, 1880 for a genus of scyphozoan jellyfish (Cnidaria, Scyphozoa) that is threatened by a senior synonym, Rhacopilus Agassiz, 1862, which has not been used since its original description. The name lucerna Haeckel, 1880 (proposed in the binomen Lychnorhiza lucerna and specific name of the type species of Lychnorhiza), which is threatened by the senior subjective synonym, RhizostomacruciatumLesson, 1830, was also not conserved. Instead, the Commission has made these two nominal species objective synonyms of each other under its specific powers by designating the extant holotype of the former as the neotype of the latter.