Metropolitan Transit Authority map, dating from July 1956. There are several anachronisms: Science Park station opened in August 1955, and route 43 was cut back to Lenox Street in June 1956.
Richard F. Lufkin
Scanned map via <a rel="nofollow" class="external text" href="https://archive.org/details/mta-1956-map/mode/2up">Internet Archive</a>