Mo. Rev. Stat. § 110.180
If for any reason the banking corporations or associations in any county fail or refuse to submit proposals to act as county depositaries as provided in section 110.140, the county commission may deposit the funds of the county with any one or more of the banking corporations, or associations in the county or adjoining counties, in the sums or amounts, and for the period of time, the commission deems advisable, at the rate of interest, not less than one and one-half percent, as is agreed upon by the commission and the banking concern receiving the deposit, the interest to be computed upon the daily balances due the county, as provided in section 110.150. Any bank or banking concern agreeing to accept deposits under this section shall provide security as required by section 110.010.
§ 110.180, RSMo
RSMo 1939 § 13852, A.L. 1959 S.B. 77