Ulnaria neobiceps sp. nov., valvocopula, SEM A a complete valvocopula B–D details from A, showing row of poroids interrupted in the middle and shelf-like projection at each apex (C, D, two arrows respectively) E, F other two apical details of valvocopula have the same apical structure. Scale bars: 20 μm (A); 3 μm (B); 2 μm (C–F).