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Bryozoa
Haplopoma graniferum (Johnston, 1847)
SUMMARY
Colonies are multiserial, forming encrusting unilamellar sheets, often quite large. The stepped growing edge exposes 3-4 pores penetrating each of the two distolateral walls of the completely calcified zooids, the pores leading to tubular pore chambers. Well preserved ancestrulae have not been observed in fossil material but in Recent specimens they are ovoidal, with a frontal shield that appears almost cribrate and an orifice with a small sinus, budding two mediolateral daughter zooids that grow in a proximal direction (Hayward & Ryland 1999, p. 314).
Autozooids are about 0.50 mm long by 0.30-0.35 mm wide, typically elongate rhomboidal to elliptical in outline shape. The frontal shield is a convex gymnocyst evenly penetrated by widely spaced pores. The small orifice is hemielliptical with a straight proximal edge, and is about 0.05 mm long by 0.08 mm wide in material from the Coralline Crag. An ascopore is present about 0.10 mm proximally of the orifice and is raised on an umbo-like protruberance. Ovicells are globular and have an ectooecium containing scattered pores and sometimes a median keel.
Avicularia are lacking.