The jurisdiction of an inferior magistrate to issue warrants must clearly appear on the papers. Commonwealth v. Fay, 126 Mass. 235. No one but a justice of the peace can be a trial justice; Pub. Sts. c. 155, § 7; and a justice of the peace duly appointed trial justice ceases to be such if his commission as justice of the peace expires before his commission as trial justice. Pub. Sts. c. 155, § 9.

It follows that a signature as trial justice involves a signature as justice of the peace, and no separate designation of the *227inferior office is necessary. The signature as trial justice means that the signer is the legal holder of that office, that is, that he is a justice of the peace holding a commission as a trial justice.

The entry must be, Judgment on the verdict.