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Fig. 2.36 Schematic longitudinal sections of hyperstomial acleithral ovicells in: ( A ) Escharella immersa (communication slit of
ooecium arrowed ); ( B ) Exochella sp.; ( C ) Lageneschara lyrulata .
Abbreviations: as ascus, bc brood cavity, bw basal wall, dz distal zooid,
ес ectooecium, en entooecium, fr frontal shield, hc hypostegal coelom,
m muscle strands of ooecial vesicle, mz maternal zooid, oc ooecial
coelom, of ovicell fl oor, op operculum, ре lumen of peristome, sc
sclerite of ooecial vesicle, tw transverse wall, v ooecial vesicle
2 Cheilostome Brood Chambers: Structure, Formation, Evolution
Fig. 2.36 Schematic longitudinal sections of hyperstomial acleithral ovicells in: ( A ) Escharella immersa (communication slit of
ooecium arrowed ); ( B ) Exochella sp.; ( C ) Lageneschara lyrulata .
Abbreviations: as ascus, bc brood cavity, bw basal wall, dz distal zooid,
ес ectooecium, en entooecium, fr frontal shield, hc hypostegal coelom,
m muscle strands of ooecial vesicle, mz maternal zooid, oc ooecial
coelom, of ovicell fl oor, op operculum, ре lumen of peristome, sc
sclerite of ooecial vesicle, tw transverse wall, v ooecial vesicle
2 Cheilostome Brood Chambers: Structure, Formation, Evolution