Plate P27. 1–3. Wilsonidium echinosuturatum (Wilson 1967c) Lentin and Williams 1976; (1) dorsal view of dorsal surface, holotype (275x); (2) same specimen as 1, ventral surface (250x); (3) same specimen as 1, dorsal surface (250x), courtesy of G.J. Wilson. 4, 5. Xenascus ceratioides (Deflandre 1937b) Lentin and Williams 1973. Same specimen in ventral view, both showing dorsal surface (both 250x). 6–8. Xiphophoridium alatum (Cookson and Eisenack 1962b) Sarjeant 1966b; (7, 8) dorsal views. All 400x. 9, 10. Stoveracysta kakanuiensis Clowes 1985; (9) dorsal surface (475x); (10) dorsal view of ventral surface (475x).

Plate P27. 1–3. Wilsonidium echinosuturatum (Wilson 1967c) Lentin and Williams 1976; (1) dorsal view of dorsal surface, holotype (275x); (2) same specimen as 1, ventral surface (250x); (3) same specimen as 1, dorsal surface (250x), courtesy of G.J. Wilson. 4, 5. Xenascus ceratioides (Deflandre 1937b) Lentin and Williams 1973. Same specimen in ventral view, both showing dorsal surface (both 250x). 6–8. Xiphophoridium alatum (Cookson and Eisenack 1962b) Sarjeant 1966b; (7, 8) dorsal views. All 400x. 9, 10. Stoveracysta kakanuiensis Clowes 1985; (9) dorsal surface (475x); (10) dorsal view of ventral surface (475x).