To determine the correct statement regarding ocean salinity, let's analyze each statement:

1. Statement A: "Average Chlorinity of the ocean is 19.2 ‰."
   • Explanation: Chlorinity refers to the concentration of chloride ions in sea water. It is indeed measured and reported in parts per thousand (‰), and the average chlorinity of ocean water is approximately 19.2‰. This statement is correct.
2. Statement B: "The belt of highest salinity is found between 20° and 40° N and S latitudes."
   • Explanation: Ocean salinity is generally highest between 20° and 40° latitudes in both the northern and southern hemispheres. This region tends to have higher evaporation rates and less precipitation, leading to higher salinity levels. This statement is correct.
3. Statement C: "The belt of highest salinity is found between 10° and 20° N and S latitudes."
   • Explanation: This statement is incorrect. As explained above, the highest salinity is not typically found between 10° and 20° N and S latitudes.
4. Statement D: "Distribution of salinity on the map is shown by means of Isohalines."
   • Explanation: Isohalines are lines on a map that connect points of equal salinity in the ocean. This method is indeed used to represent salinity distribution, similar to how isobars and isotherms represent pressure and temperature, respectively. This statement is correct.

Based on the analysis:

• Correct Statements: A, B, and D

Therefore, the correct answer is: A, B & D Only.