The county treasurer shall be deemed the ex officio treasurer of the district unless the board, by resolution, and with the written consent of the county treasurer, appoints a district treasurer. If the resolution is adopted and a district treasurer is appointed, all references to a county treasurer or county treasury within this division shall be deemed to apply to the treasurer appointed by the board and the treasury of the district, and no further consent of the county treasurer will be required. The person so appointed shall file a bond with the board in the manner prescribed in Section 50659.