Using 16S, COI, and ITS DNA sequences, it was possible to link a Norwegian marine hydroid formerly known as Leuckartiara abyssi (G.O. Sars, 1874) to a Neoturris medusa occurring in the same region. Although the Norwegian medusae showed some slight morphological differences to Mediterranean Neoturris pileata, DNA sequence comparisons show that they must be conspecific. A Mediterranean specimen of N. pileata showed less sequence divergences to the Norwegian Neoturris than was found within this latter population. The morphological differences are likely only age- and environmentally related. Leuckartiara abyssi is thus a subjective synonym of Neoturris pileata (Forsskål, 1775). The sequence analyses were embedded in a comparison with other members of the family Pandeidae. Contrary to the case for most other hydrozoans investigated, 16S sequences show very little divergences within the genus Catablema and it is thus not a good barcoding marker for this genus. COI sequences showed about three times greater divergence than 16S within selected pandeid species clades and are more suitable to investigate Catablema species, although also for COI the divergences within this group remain rather small. Catablema nodulosum Bigelow, 1913 was found to be most likely conspecific with Catablema vesicarium (A. Agassiz, 1862) and was therefore accepted only as a subspecies of the latter, thus following the opinion of most other prominent taxonomists of the last century. Medusae referred to Catablema multicirratum Kishinouye, 1910 originating from either the NE Pacific or the Eurasian sector of the Arctic Sea could belong to two distinct species. The medusa Leuckartiara longicalcar n. spec. is described and illustrated. It occurs along the coast of North America from British Columbia to California and has been confused previously with L. octona (Fleming, 1823).
