The scolecodont genera Nereidavus Grinnell, 1877, and Protarabellites Stauffer, 1933, have been used for several different fossil polychaete taxa over the years. Nereidavus is here considered a nomen dubium, as the holotype of the type species is lost and the original information is insufficient for identification. Protarabellites is reevaluated and constitutes, besides Ramphoprion, a second genus in the family Ramphoprionidae. The “paratype” of N. varians (named Ramphoprion sp. in this paper), and the holotype of P. humilis are redescribed.