Otocyst: an auditory or ear-like vesicle.
Otolith: a little ear-bone: granules or concretions found in an otocyst.
Outer lobe: of maxilla = galea; q.v.
Outer margin: the outer edge of wing, between apex and hind angle.
Ovo, Ovum: the eggs; an egg.
Ova glebata: eggs laid or concealed in lumps of dung.
Ova imposita: eggs laid in the substance that is to serve as food for the larva.
Oval: egg-shaped, with both ends similar.
Ova pilosa: eggs that are covered with hair: usually from the abdomen of the female.
Ovarian tube: a tubular structure in which are developed the cells forming the future ova: a single one of the mass which, taken together, form the ovaries.