Genus Parathyone Deichmann, 1957

Emended diagnosis (modified from Prata et al., 2020). Small-medium-sized forms (up to 100mm long), Ten dendritic tentacles of equal size or ten dendritic tentacles, ventral pair reduced. Tube feet scattered over entire body. Calcareous ring lacking posterior processes; radial plates united to interradial plates along their entire length. Body wall ossicles: four holed to multilocular cups; multiperforated plates and knobbed buttons. Tentacles and introvert with cups knobbed on inner and outer faces. Ambulacral feet with supporting rods and end plate.

Type species. Parathyone surinamensis (Semper, 1867); by original designation. Type locality: Surinam.

Species included (genera of the original combination are indicated within brackets). Parathyone surinamensis (Semper, 1867) [ Thyone], Parathyone suspecta (Ludwig, 1875) [ Thyone] (type locality: Barbados), Parathyone braziliensis (Verrill, 1868) [ Thyone] (type locality: Abrolhos, southern Bahia, Brazil) and Parathyone itapuaensis sp. nov. Thyone (Sclerodactyla) braziliensis Verrill, 1868, was recently transferred to Parathyone by Prata et al. (2020).