Miss. Code § 65-11-45
[With regard to any county which is exempt from the provisions of Section 19-2-3, this section shall read as follows:]
The State Fiscal Management Board shall notify the board of supervisors of each county of the amount of money to be available for expenditure in such county from any appropriation made by the state for the purpose of Sections 65-11-39 through 65-11-59. The board of supervisors, upon the receipt of such notice, shall divide the amount available for such county among the five (5) supervisors districts. All funds which may be appropriated for the purpose of said sections shall be expended for materials and labor in construction and improvement of county roads and bridges selected by the board of supervisors of each county. However, the board of supervisors shall first select for construction and reconstruction all school bus routes and, next, rural mail routes.
Miss. Code § 65-11-45