CLASS I, II AND III CITIES.
Every Class I, II and III city which is not a participating public employer in the said West Virginia Public Employees Retirement System is hereby empowered and authorized to and may establish and maintain an "employees retirement and benefit fund" in accordance with the provisions of this section two and sections three through fourteen of this article. Any Class I, II and III city which has heretofore established such a fund in accordance with the acts of the Legislature referred to in section fifteen of this article may continue to maintain said fund in accordance with the provisions of this section two and sections three through fourteen of this article, or said acts, as specified in said section fifteen.