on summary conviction to a fine not exceeding £500 or to imprisonment for a term not exceeding six months or to both such fine and such imprisonment and shall in addition be liable to a further fine not exceeding £50 for every salmon and £10 for every trout so bought, sold, offered or exposed for sale or found in his possession;

on conviction on indictment toF2 an unlimited fine or to imprisonment for a term not exceeding two years or to both such fine and such imprisonment.]

that he had the salmon or trout in his possession as a common carrier and not otherwise; and

that at the time at which the salmon or trout was accepted by him for carriage, the consignor delivered to him a certificate in writing signed by the consignor to the effect that the salmon or trout was lawfully captured.

he proves that he acquired the fish from a person who then was, or whom he believed on reasonable grounds then to have been, the holder of a dealer's licence issued under the succeeding provisions of this Part; or

he satisfies the court that he had no reason to suppose the fish to have been unlawfully captured, and that he took all reasonable precautions and exercised all due diligence to avoid the commission of such an offence;