A–F SEM micrographs, RV internal views of C. crisscrossis sp. nov. from Qingyi River A–C complete internal valve D irregular hyaline central area and the proximal raphe fissures are bent to opposite sides E weakly elevated helictoglossae F the areolae are occluded by round lattice-structured hymens. Scale bars: 5 µm (A–C); 1 µm (D–F).