The office of a member of the Council shall become vacant upon his death, resignation or removal from office. A vacancy in the Council shall be filled for the remainder of the unexpired term at the next regular municipal election following not less than 60 days upon the occurrence of the vacancy, but the Council by a majority vote of all its remaining members shall appoint a qualified person to fill the vacancy until the person elected to serve the remainder of the unexpired term takes office. If the Council shall fail to fill the vacancy for the interim period as provided herein above within thirty days following the occurrence of the vacancy, its power to fill the vacancy shall lapse and the Mayor shall fill the vacancy during the interim period of appointment.