Onychaster, [203]
Onychaster, [502]
Oocyte (a cell which by unequal divisions or mere nuclear divisions becomes converted into an oosphere), [100]
Oogamete of Coccidiaceae, [100] f.
Ookinete (active zygote) or oosperm, of Acystosporidae, [104] f.;
of Trypanosoma noctuae, [120]
Oolitic limestones, nucleus of concretions of, [70]
Oosperm, [34];
of Sporozoa, [96] f.;
of Volvox globator, [127] f.