County and town boards of education and special school district boards, whenever they deem it advisable for the purpose of a more economical administration and the improvement of the efficiency of the schools, may make a contract to operate the school or schools of such town under the general supervision of the county director of schools; provided, that nothing in this section shall be construed to change the general method of distribution of county and state school funds between the county and such towns on the basis of average daily attendance as provided in this title; and provided, further, that nothing in this title shall be construed to change or repeal Chapter 160 of the Private Acts of 1915.