§ 21. Duties of agent. Such agent shall annually, on or before the first Monday of June, prepare and transmit to the department of social welfare a correct enumeration of such of the Indians of whom he is agent, as are entitled to receive annuity moneys from the state. The department of social welfare shall, upon receipt of such enumeration and undertaking, certify to the comptroller such enumeration and its approval of such undertaking and send to such agent the annuity moneys payable by the state to the Indians of whom he is agent for which purpose such moneys shall be paid to the department of social welfare from the treasury on the audit and warrant of the comptroller upon requisitions approved by the department of social welfare. Such agent shall thereupon distribute such moneys to the Indians of whom he is agent who are entitled thereto, paying the same to heads of families and individuals so far as practicable, and shall forthwith report such distribution to the department of social welfare, which shall certify such report to the comptroller. Such agent shall protect the rights and interests of the tribe of which he is agent, and perform such other duties in relation to them as may be required by the department of social welfare.