FIGURES 23–28 in Taxonomic notes on some Cheilostomata (Bryozoa) from Madeira

FIGURES 23–28. Plesiocleidochasma porcellanum (Busk, 1860) n. comb., lectotype, NHMUK 1899.7.1.1726. 23, surface of mature colony near the growth margin; note the presence of three spines in early ontogenetic zooids. 24, primary orifice. 25, autozooids and maternal zooids at some distance to the growth margin, with the ooecia covered and immersed by secondary calcification. 26, close-up of ovicell; note the small, median fenestra in the proximal ooecial margin and the absence of lateral incisions. 27, early stages of ooecium formation, with most of the exposed ectooecium quickly covered by secondary calcification of the distal zooid (arrows indicate the advancing fronts). 28, close-up of avicularium. Scale bars: Fig. 23 = 200 µm; Fig. 24 = 40 µm; Fig. 25, 27 = 100 µm; Fig. 26 = 50 µm; Fig. 28 = 10 µm