Zonae

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Zona \Zo"na\, n.; pl. {Zonae}. [L., a girdle. See {Zone}.]
     A zone or band; a layer.
     [1913 Webster]
  
     {Zona pellucida}. [NL.] (Biol.)
     (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} [NL.] (Biol.), a radiately striated membrane
        situated next the yolk of an ovum, or separated from it by
        a very delicate membrane only.
        [1913 Webster]