The brown algal family Scytosiphonaceae has recently received considerable attention resulting in the description of several new genera and species. However, members of the genus Scytosiphon and Petalonia remain polyphyletic. By integrating multi-gene phylogenetic data (mitochondrial cox3 and plastid psaA and rbcL genes) with their known morpho-anatomies and life histories, we herein resurrect Hapterophycus canaliculatus, currently considered a member of genus Scytosiphon, and transfer Scytosiphon tenellus to the genus Petalonia
