The distance or bearing or both shown on the map for any zone district boundary line shall determine and govern the location of such boundary lines.

Where no distance or bearing is expressly stated on the map, the zone district boundary lines are municipal boundary lines, center lines of streets, existing lot and tract lines and other expressly delineated boundary lines, as the same are indicated on the map.

Where no express distance is shown nor boundary line indicated in accordance with Subsection b of this subsection, the depth of zone districts shall be deemed to be the distance from the nearest parallel street right-of-way line as regulated in the following schedule: