Ophioplinthaca athena A. H. Clark, 1949 (IDSSE-EEB-SW0110) A dorsal disc B ventral disc C center of the disc D–E disc spines F radial shield G lateral disc H оral frame I ventral side of the arm base J dorsal side of the arm base K dorsal arm L ventral arm M lateral arm. Abbreviations: as adoral shield, ass adoral shield spine, dap dorsal arm plate, das dorsal arm spine, dp disc plate, gs genital slit, j jaw, lap lateral arm plate, m madreporite, os oral shield, rs radial shield, ts tentacle scale, vap ventral arm plate, vas ventral arm spine. Scale bars: 2 mm (A, B); 1 mm (C, F–K, M); 500 µm (L); 200 µm (D, E).