Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 160, § 188

A railroad corporation shall not demand or receive for any single ticket bought or fare paid on a train or elsewhere than at its ticket offices more than ten cents in excess of the tariff rates charged at its ticket offices. When such excess is received, the conductor or other person receiving it shall give to the passenger a printed certificate which shall entitle him to receive the excess so paid at any station of the corporation in exchange for such certificate. A railroad corporation violating any provision hereof shall be punished by a fine of not less than ten nor more than fifty dollars.