An Act creating a Pennsylvania Municipal Retirement System for the payment of retirement allowances to officers, employes, firemen and police of political subdivisions and municipal authorities and of institutions supported and maintained by political subdivisions and municipal government associations and providing for the administration of the same by a board composed of the State Treasurer and others appointed by the Governor; imposing certain duties on the Pennsylvania Municipal Retirement Board and the actuary thereof; providing the procedure whereby political subdivisions and municipal authorities may join such system, and imposing certain liabilities and obligations on such political subdivisions and municipal authorities in connection therewith, and as to certain existing retirement and pension systems, and upon officers, employes, firemen and police of such political subdivisions, institutions supported and maintained by political subdivisions, and upon municipal authorities; providing for the continuation of certain municipal retirement systems now administered by the Commonwealth; providing certain exemptions from taxation, execution, attachment, levy and sale and providing for the repeal of certain related acts.