The Secretary of the Interior is authorized, wherever in his discretion such action would be for the best interest of the Indians, to cause a final roll to be made of the membership of any Indian tribe; such rolls shall contain the ages and quantum of Indian blood, and when approved by the said Secretary are declared to constitute the legal membership of the respective tribes for the purpose of segregating the tribal funds as provided in section 162 of this title, and shall be conclusive both as to ages and quantum of Indian blood: , That the foregoing shall not apply to the Five Civilized Tribes or to the Osage Tribe of Indians, or to the Chippewa Indians of Minnesota, or the Menominee Indians of Wisconsin.1Provided