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Bryozoa
Cribrilina watersi Andersson, 1902
SUMMARY
Colonies are encrusting, multiserial, sheet-like, unilamellar or rarely bifoliate due to back-to-back growth. Each autozooid has 8-10 distolateral pore chambers which may be visible in abraded colonies and at growing edges. The ancestrula has a costate frontal shield.
Autozooids are moderately small, 0.38-0.60 mm long by 0.28-0.42 mm wide, and roughly rhombic in outline shape. The gymnocyst is normally not visible. The gently convex frontal shield is formed by 5-13 costae (including the apertural bar), most often 7-11, linked by stout lateral costal fusions and united at the centre of the frontal shield. There are 1-4 intercostal pores and each costa has 0-2 lumen pores placed haphazardly. The apertural bar is very stout with a variably developed median mucro having one or two lumen pores on its proximal side. The sunken orifice is D-shaped, broader than long, with one median, flattened oral spine in non-ovicellate zooids but no spines in ovicellate zooids. Ovicells are small, short and have a single, inverted T-shaped or several smaller proximal windows in the ectooecium.
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.