Sec. 1. Any member of a retirement, disability and death compensation fund established by any county of this State pursuant to Section 62 of Article XVI of the Constitution of Texas, by written designation filed in such form and with such officer or employee as the Commissioners Court shall prescribe, may provide that the contributions made by such member to such fund, together with interest (if any) assigned to such contributions under such plan, shall be paid, in the event of the death of such member before retirement with an allowance of benefits from said fund, to such beneficiary as may be named by him in such written designation. The member may change the beneficiary so designated, or revoke a designation previously made by filing with the Commissioners Court, or such officer or employee as may be designated by such Court, a notice in writing in such form as the Court may prescribe, of such change or revocation. In the event the member dies before such retirement, without so designating a beneficiary to receive his accumulated contributions and interest if any, or in the event the beneficiary so designated predeceases the member, such sums shall be paid to his estate. Payment of the accumulated contributions and interest of a member to the executor or administrator of his estate, or to his designated beneficiary, shall discharge the fund and its administrative officers from any other or further liability therefor.