The transportation, importation, sale, or possession of the skins of fur seals or sea otters is prohibited if such skins were taken contrary to the provisions of section 2 of the act of February 26, 1944 (58 Stat. 100-104) or, the case of such skins taken under the authority of the act or any fur-seal agreement, if the skins are not officially marked and certified as required by section 2 of the act. Section 16 makes the act inapplicable to skins taken for scientific purposes under a special permit.