The rate of contribution of any member shall apply only to so much of the salary actually paid to him, plus the monetary value as determined by the board of board, lodging, fuel, laundry, and other advantages of any nature furnished to him in payment for his services as does not exceed five hundred dollars ($500) a month. The amount shall be deducted by the county auditor, or other officer charged with the duty of drawing salary or wage warrants, from the first salary or wage warrant drawn in each month in favor of each member and shall be paid to the county treasurer and placed to the credit of the member’s account.