Whoever, for a reward paid or promised to him in that behalf, undertakes to locate for an intending purchaser, settler, or entryman any public lands of the United States subject to disposition under the public-land laws, and who willfully and falsely represents to such intending purchaser, settler, or entryman that any tract of land shown to him is public land of the United States subject to sale, settlement, or entry, or that it is of a particular surveyed description, with intent to deceive the