Bonds purchased from any taxing district of the state shall be in the denomination required by the school employees retirement board in its resolution of purchase, or the board may by its resolution require that all bonds of any series of bonds purchased by it from any taxing district be consolidated and issued as one bond, the principal amount of which shall be equal to the aggregate amount of all the bonds of said series, which principal together with the interest thereon shall be paid in installments evidenced by and payable upon the surrender of combined principal and interest coupons attached thereto, which coupons shall each separately state the amounts of principal and interest included therein.
R.C. §3309.16