Sertularella
Diagnostic description:
Colony erect branched or unbranched, monosiphonic or polysiphonic, hydrocaulus and hydrocladia when present, with two longitudinal rows of alternate, sessile hydrothecae, hydrothecal margin with four teeth, submarginal teeth present or absent, operculum pyramidal, composed of four triangular valves, hydranth with abcauline caecum, gonophores as solitary fixed sporosacs, acrocyst in some species.