Zona
Zona , noun
[Latin, a girdle. See Zone.]
A zone or band; a layer.
Collocations (2)
Zona pellucida (Biology) , (a) The outer transparent layer, or envelope, of the ovum. It is a more or less elastic membrane with radiating striae, and corresponds to the cell wall of an ordinary cell. See Ovum, and Illust. of Microscope. (b) The zona radiata.
Zona radiata (Biology) , a radiately striated membrane situated next the yolk of an ovum, or separated from it by a very delicate membrane only.