The new genus Dastychius has been instituted for the species Isohypsibius improvisus Dastych, 1984. It has claws of the Isohypsibius type, rigid buccal tube without ventral lamina and with ridge-shaped apophyses for the insertion of the stylet muscles; peribuccal lamellae absent; peribuccal papulae seem to be present but the datum should be confirmed; pharyngeal bulb with apophyses and placoids...