Mass. Gen. Laws ch. 231 § 103
If a party elects to bring in any district court any action or other civil proceeding which he might have begun in the superior court, he shall be deemed to have waived a trial by jury and his right of appeal to the superior court, unless within thirty days of commencement of the action or service of a responsive pleading, or within such further time as the court may allow, a plaintiff files a claim to a jury trial in the superior court with the district court and within thirty days after notice of the decision or finding files an entry fee of fifty dollars and bond in accordance with the second paragraph of section one hundred and four; provided, however, that if any claim, counterclaim or cross-claim is asserted against a plaintiff who has elected to bring such action or other civil proceeding in any district court, said plaintiff may of right remove said action or proceeding and claim a jury trial in the same manner and upon the same terms as set forth in said section one hundred and four; and, provided further, that if any compulsory counterclaim is asserted by a defendant, said defendant may of right remove the action and claim a jury trial in the same manner and upon the same terms as are set forth in said section one hundred and four. This section and sections one hundred and four to one hundred and ten, inclusive, shall not apply to actions or counterclaims under the provisions of chapter two hundred and thirty-nine.
Mass. Gen. Laws ch. 231, § 103