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Fig. 2.34 Schematic longitudinal sections of hyperstomial cleithral ovicells in: ( A ) Micropora notialis (ooecium formed by distal autozooid);
( B ) Micropora brevissima (ooecium is formed by an interzooidal avicularium). Abbreviations: av avicularium, bc brood cavity, bw basal wall,
cr cryptocyst, dz distal zooid, ес ectooecium, en entooecium, fm
membranous frontal wall, hc hypostegal coelom, m muscle strands of
ooecial vesicle, mz maternal zooid, oc ooecial coelom, of ovicell fl oor, op
operculum, pl placental analogue, tw transverse wall, v ooecial vesicle
2 Cheilostome Brood Chambers: Structure, Formation, Evolution
Fig. 2.34 Schematic longitudinal sections of hyperstomial cleithral ovicells in: ( A ) Micropora notialis (ooecium formed by distal autozooid);
( B ) Micropora brevissima (ooecium is formed by an interzooidal avicularium). Abbreviations: av avicularium, bc brood cavity, bw basal wall,
cr cryptocyst, dz distal zooid, ес ectooecium, en entooecium, fm
membranous frontal wall, hc hypostegal coelom, m muscle strands of
ooecial vesicle, mz maternal zooid, oc ooecial coelom, of ovicell fl oor, op
operculum, pl placental analogue, tw transverse wall, v ooecial vesicle
2 Cheilostome Brood Chambers: Structure, Formation, Evolution