A city of the primary class may convey cemetery lots owned by such city by certificates signed by the mayor and countersigned by the city clerk under seal of the city, specifying that the person to whom such certificate is issued is owner of the lot or lots described therein by number as laid down on such plat or map, for the purpose of interment. Such certificate shall vest in the proprietor, his or her heirs and assigns, a right in fee simple to such lot or lots for the sole purpose of interment under the regulations of the city council.