Watersipora encrusting bryozoan

W. subovoidea is a calcified, encrusting bryozoan. Its colonies are variable in appearance, and may be unilaminar and encrusting, to bilaminar and frilled. Living specimens are brownish orange to black. Polypides are bright orange-red. Zooids are large, and irregularly shaped, measuring an average of 0.82 X 0.38 mm in size. The frontal surface is curved and evenly perforated by large pores. The orifice is oval anteriorly with a small semicircular sinus which lends an overall mushroom-shaped appearance to the orifice. The operculum is generally dark brown to black. No avicularia are present. Average lophophore diameter is approximately 0.66 mm. An average of 21 tentacles is present on the lophophore.
(http://www.sms.si.edu/irlspec/Waters_subovo.htm)
Spotted at Karnagio shipyards, Pefkakia, Volos city, Greece.