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Bryozoa
Cribrilina cryptooecium Norman, 1903
SUMMARY
Colonies are encrusting, multiserial, sheet-like, unilamellar or multilamellar through self-overgrowth, sometimes becoming large with up to 2000 zooids. About eight distolateral pore chambers per zooid may be visible in abraded colonies and at growing edges. The ancestrula is tatiform with 9 spines.
Autozooids are moderately small, 0.39-0.56 mm long by 0.22-0.35 mm wide, and roughly rectangular in outline shape. The gymnocyst is normally not visible. The gently convex frontal shield is formed by 9-12 costae (including the apertural bar) linked by stout lateral costal fusions and united at the centre of the frontal shield. Intercostal pores usually number 3. Each costa has a single lumen pore approximately half way between the midpoint and inner tip. The apertural bar is thick and bears a median mucro, occasionally doubled when the left and right components do not meet fully, with a pair of lumen pores on the proximal side. The orifice is D-shaped, broader than long, with 2 oral spines which lie close to the mid-line in non-ovicellate zooids but are more laterally positioned in ovicellate zooids Ovicells have a proximal transverse ridge, often raised centrally, a variably developed distal umbo, and lack pores.
Avicularia are adventitious, paired on either side of the orifice, directed distolaterally, with a short triangular rostrum, raised at its distal end, a rounded proximal end, and an uncalcified pivotal bar.