Prior to the adoption of any zoning regulations the Board, as it affects its jurisdiction, shall request the Commission to recommend the boundaries of the various districts and appropriate regulations to be enforced therein. The Commission shall make a preliminary report of its recommendations for such zoning regulations and shall hold one or more public hearings thereon. Such hearings may be adjourned from time to time. Within ninety (90) days after the final adjournment of such hearings, the Commission shall make its final report to the Board, together with a summary of the results of the public hearings, its proposed zoning regulations, map or maps, and suggested resolution. The Board may then adopt the proposed regulations or refer them back to the Commission for further consideration.