Section 18
SEC. 18. Contribution of Officers.&mdashOfficers in the active service shall contribute monthly to the Fund an amount equivalent to seven per cent of their monthly base and longevity pay. Persons receiving monthly retirement or separation benefits under this Act shall contribute monthly to the Fund an amount equivalent to three per cent of their monthly retirement or separation benefits. Any person entitled to any of the benefits provided under this Act may, at his option, elect to receive the full amount of his personal contributions to the Fund with interest at six per cent per annum or the benefits to which he is entitled under this Act. Any person honorably separated from the commissioned service of the Bureau of Coast and Geodetic Survey who is not entitled to any of the retirement or separation benefits provided in this Act shall be refunded the full amount of his personal contributions with interest at six per cent per annum.