Upon the heirs or devisees known and resident within the Virgin Islands the citation referred to in section 495 (b) of this title shall be served and returned as a summons, and upon an heir or devisee unknown or non-resident it may be served by publication or posting, or both, for not less than four weeks, or for such further time as the court may prescribe. When service is had by posting, the citation shall be posted at not less than three public places within this territory, one of which shall be the post office nearest the place where the decedent resided at the time of his death. When service of the citation is made by publication or posting, there shall be given with it a brief description of the property described in the petition.