‘Nipple-shaped’ sensilla on pharyngeal plate and hypopharyngeal spines of hypopharynx of Lithobius. ALithobius (Lithobius) dentatus; pairwise hypopharyngeal spine fields laterally to pharyngeal plate; transverse line of several ‘nipple-shaped’ sensilla BLithobius (Monotarsobius) aeruginosus; transverse line of a few ‘nipple-shaped’ sensilla on the pharyngeal plate; arrow indicates a pore CLithobius (Lithobius) pyrenaicus; ‘nipple-shaped’ sensilla arranged in a zig-zag-pattern DLithobius (Lithobius) validus; several ‘nipple-shaped’ sensilla arranged in a transverse line with some offset sensilla E–FLithobius (Lithobius) forficatusE clustered ‘nipple-shaped’ sensilla F high magnification of ‘nipple-shaped’ sensilla from Fig. 11E. hsp – hypopharyngeal spine field, mo – mouth opening, nsc – cluster of ‘nipple-shaped’ sensilla, pp – pharyngeal plate.