The St. Louis Rams agreed to terms yesterday on a five-year deal with free agent safety Kim Herring. Herring started all 16 games last season for the Baltimore Ravens as an intregal part of a defense which set an NFL record for fewest points allowed in a 16-game season. To make room under the salary cap for Herring, safety Keith Lyle was released. Lyle had spent his entire career with the Rams until yesterday.