Section 33. No land within a town shall be laid out or used as a race ground or trotting park without the previous consent of and location by the mayor and city council, the town council in a town having a town council or the selectmen in any other town, who may regulate and alter the terms and conditions under which the same shall be laid out, used or continued in use and may discontinue the same when in their judgment the public good so requires; and no land shall be used for any of the purposes declared unlawful in section thirty-one.