The period of trust on lands allotted to Indians of the Klamath River Reservation, California, which expired , and the legal title to which is still in the United States, is reimposed and extended for a period of twenty-five years from : , That further extension of the period of trust may be made by the President, in his discretion, as provided by section 348 and .section 391 of this titleJuly 31, 19191919-07-31July 31, 19191919-07-31Provided