(a) In any county of the first class lying wholly within a levee district and within which there is situated a city of more than forty thousand (40,000) population according to the last federal decennial census;

(b) In any county bordering on the Gulf of Mexico or Mississippi Sound, having therein a test facility operated by the National Aeronautics and Space Administration;

(c) In any county bordering on the Alabama state line, traversed by the Tombigbee River, and in which is situated a senior institution of higher learning;

(d) In any county of the second class wherein Interstate Highway 55 and State Highway 22 intersect and which is also traversed in whole or in part by U. S. Highways 49 and 51, and State Highways 16, 17 and 43 and the Natchez Trace;

(e) In any Class 4 county having population in excess of twenty-five thousand (25,000) according to the 1960 federal census, traversed by U. S. Highway 55 and wherein State Highways 12 and 17 intersect;

(f) In any county created after 1916 through which the Yazoo River flows;

(g) In any Class 4 county having a land area of six hundred ninety-five (695) square miles, bordering on the State of Alabama, wherein the Treaty of Dancing Rabbit was signed and wherein U. S. Highway 45 and State Highway 14 intersect;

(h) In any county bordering on the Mississippi River wherein lies the campus of a land-grant institution or lands contiguous thereto owned by the institution;

(i) In any county lying within the Yazoo-Mississippi Delta Levee District, bordering upon the Mississippi River, and having a county seat with a population in excess of twenty-one thousand (21,000) according to the federal census of 1960;

(j) In any Class 3 county wherein is partially located a national forest and wherein U. S. Highway 51 and State Highway 28 intersect, with a 1960 federal census of twenty-seven thousand fifty-one (27,051) and a 1963 assessed valuation of Sixteen Million Six Hundred Ninety-two Thousand Three Hundred Four Dollars ($16,692,304.00); and

(k) In any Class 1 county wherein U. S. Highway 49 and State Highway 16 intersect, having a land area in excess of nine hundred thirty square miles.