The only representative of the Helmetophoridae,
Helmetophorus rankini Hartman, 1978, is redescribed and transferred to the Flabelligeridae. The species shares in common with the Flabelligeridae a papillated body surface, a buccal region with branchiae and grooved palps that is covered (partially)by a cephalic hood, weakly developed parapodia, and cross-barred capillaries.
