§ 20. Appointment, term of office and qualifications of the agent of the Onondaga Indians. The offices of agent of the Onondaga Indians residing on the Onondaga reservation, and of agent of the Onondaga Indians residing on the Allegany, Cattaraugus, Tuscarora and Tonawanda reservations, are combined effective July one, nineteen hundred sixty-one, and commencing on that date there shall be a single office of agent of the Onondaga Indians. Such agent shall be appointed by the state commissioner of social welfare and shall exercise and perform his power and duties under the supervision, direction and control of the department of social welfare. The term of office of such agent shall be five years. The compensation of such agent shall be paid by the state and shall be an annual salary of twelve hundred dollars. Such agent shall not be further reimbursed for his expenses. Such agent shall reside in Onondaga county, near the Onondaga reservation.