Subsection (b) of section 321, Part II, Title III, of the Transportation Act of 1940 provides that in the case of a railroad carrier, or a predecessor, which received a land grant to aid in the construction of any part of its railroad, the laws relating to compensation for certain Government transportation services shall continue to apply as though subsection (a) of section 321 had not been enacted unless the carrier shall file on or before September 18, 1941, with the Secretary of the Interior, in the form and manner prescribed by him, a release of any claim it may have to lands, interests in lands, compensation, or reimbursement on account of lands or interests in lands so granted, claimed to have been granted or claimed should have been granted. Section 321 provides further that nothing therein shall be construed as preventing the issuance of patents confirming the title to such uncertified or unpatented lands as the Secretary of the Interior shall find have been sold prior to September 18, 1940, to innocent purchasers for value. Subsection (b) of section 321 authorizing the issuance of such patents is not an enlargement of the grants, and does not extend them to lands not already covered thereby and, therefore, has no application to lands which for various reasons, such as mineral character, prior grants, withdrawals, reservations, or appropriation, were not subject to the grants. It does apply, however, to lands selected under remedial or lieu acts supplemental to the original grants as well as to primary and indemnity lands. Classification under section 7 of the Taylor Grazing Act of June 28, 1934 (48 Stat. 1269), as amended by the Act of June 26, 1936 (49 Stat. 1976; 43 U.S.C. 315f), will not be required where the sold land is such as the company was authorized by law to select.