The director may agree with the board of supervisors of any county in which no salary was established for the position of commissioner for January, 1959, that the state will pay not to exceed six thousand six hundred dollars ($6,600) per year of the amount to be used for payment of the salary of a commissioner for such county, or of a commissioner who is employed pursuant to Section 2124. The amount which is paid the county shall not, however, exceed two-thirds of the amount of the salary which is paid to the commissioner.