Miss. Code Ann. § 21-33-13: Miss. Code Ann. § 21-33-13

The clerk, or tax collector, of every municipality shall copy from the roll or schedule filed with the clerk of the board of supervisors by the state tax commission the assessment of private car companies, and he shall determine the amount by taking the number of miles of each railroad over which the cars of any company, traveled through the respective municipalities, and the number of miles of each railroad over which the cars of any such company traveled which lies in any separate, adjacent, annexed territory constituting with a municipality a separate school district. He shall copy the assessed value per mile of each company over any railroad or railroads, operating through such municipality and separate, adjacent, annexed territory, and shall determine the assessment of each company by multiplying the valuation of each company apportioned to each mile of railroad by the number of miles of railroad over which the cars of any such company have traveled lying in such municipality or separate, adjacent, annexed territory. The assessment so determined, plus the value of any other property assessed, shall constitute the assessment of the property of the respective companies within the municipality and in the separate, adjacent, annexed territory constituting a separate school district. All such copies and assessments made as herein provided shall be placed in the hands of the municipal tax collector and be his warrant for the collection of municipal and separate school district taxes.