FIGURE 6. Hornera currieae n in Hornera currieae n. sp. (Cyclostomatida: Horneridae): a new bathyal cyclostome bryozoan with reproductively induced skeletal plasticity

FIGURE 6. Hornera currieae n. sp. branch development and ultrastructure. A. Abfrontal surface of developing branch tip with prominent pustulose keels and scattered pustules (NIWA 8443). B–C. Comparison of branches under SEM and light microscopy highlighting smooth walls, widely spaced autozooidal openings and sparse cancelli (NIWA 8443). D–F. Representative skeletal ultrastructural fabrics: D. Seeding zone with directionally neutral crystallite imbrication; quadrilateral tablets are possibly rhombic semi-nacre (TAN0104 stn 153). E. Fabric dominated by proximally imbricated hexagonal semi-nacre (TAN0104 stn 115). F. Mature wall comprising pseudofoliated fabric arising from fused or expanded hexagonal semi-nacreous tablets (TAN0104 stn 153). G–H. High magnification views showing variability of surface crystallites in seeding zones: G. Large rhombic crystallite undergoing screw dislocation (left); hexagonal tablet with distinct sectoring and trilete arrangement (right) (TAN0104 stn 153). H. Large rectangular crystallite at left, with central mound at point of origin; various other crystallites with hexagonal or rhomboidal interfacial angles (TAN0104 stn 153). Scale bars: A, 100 µm; B, C, 200 µm; D, F, 10 µm; E, 5 µm; G, H, 1 µm.