Genus Tulpa Stechow, 1921

Diagnosis. Colonies stolonal or forming erect, monosiphonic stems. Cauline hydrothecae alternate, with strong tendency to unilateral arrangement. Hydrothecae at end of pedicels without distal sub-hydrothecal spherule. Hydrotheca tubiform, remarkably large and deep, with more or less pronounced polygonal structure, and with a basal annular perisarcal thickening. Rim of hydrothecal aperture typically sinuous and more or less turned outwards, with or without cusps. Cnidome consisting of small microbasic mastigophores and large?atrichous isorhizas.

List of species clearly referable to Tulpa in this study:

Tulpa tulipifera (Allman, 1888) (= Campanularia tulipifera Allman, 1888)

Tulpa diverticulata Totton, 1930

Tulpa costata Gravier-Bonnet, 1979

Tulpa peculiaris sp. nov.

Tulpa revelata sp. nov.