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Fig. 2.45 Schematic longitudinal section of hyperstomial subcleithral
ovicell in Fenestrulina malusii ( arrow indicates ooecial communication
pore; arrowhead indicates calcifi ed elevation surrounding entooecium
base; position of operculum during embryonic incubation shown by
dotted line ). Abbreviations: as ascus, bc brood cavity, bw basal wall,
dz distal zooid, ес ectooecium, en entooecium, fr frontal shield,
hc hypostegal coelom, mz maternal zooid, ос ooecial coelom, of ovicell
fl oor, op operculum, os oral spine, tw transverse wall
Figures