If the proposed amendment intends to rezone or redistrict ten (10) or less parcels of land, as listed on the tax duplicate, written notice of the hearing shall be mailed by the Clerk of Council, by first class mail, at least twenty (20) days before the day of the public hearing to all owners of property within, contiguous to and directly across the street from such area proposed to be rezoned or redistricted to the address of such owners appearing on the County Auditor's current tax list or the Treasurer's mailing list and to such other list or lists that may be specified by Council. The failure to deliver the notification, as provided in this Section, shall not invalidate any such amendment. The notice shall contain the time and place of the public hearing and the nature of the amendment.