Synedrosphenia recta sp. nov. Chuuk TK28 except as noted A, C holotype and details of pole at two focal planes, showing valve face and valvocopula B, D–F specimen in SEM with details of pole at 0° tilt (D), arrows showing position of annulus, and 60° tilted views of central portion (E) showing copula and opposite pole (F) showing copula and valvocopula with apical notch (arrow) G, H internal view of a pole with valve and valvocopula at 60° tilt, showing apical notch (arrow), and at 0° tilt, showing apical area without transapical costae; arrows show inferred position of annulus as in D and absence of longitudinal costae I polar view of valve with valvocopula, showing apical notch J broken valve showing continuous transverse costae (arrow) and pores on pars interior of valvocopula (arrowheads) K specimen from Guam (GU76B-4), showing fragments of very narrow pleura (pl, arrows) L specimen from Jaluit (J5), pole of valve without valvocopula, showing continuous rim and absence of longitudinal costae; two-way arrow marks position of annulus, as in D, H. Scale bars: 50 µm (A, B); 10 µm (C); 5 µm (D–L).