The Perfect Guest

C. Z. Guest was one of the monarchs of New York society, who was a perennial selection on the best-dressed list, a noted horsewoman and an authority on gardening. As a young girl her name was Lucy, but she soon became C. Z. when her brother, Alexander, could not pronounce ''sister.''

When she was married in 1947 to Winston Frederick Churchill Guest, an international polo star, heir to the Phipps steel fortune and a second cousin of Winston Churchill, the ceremony was held at the home of Ernest Hemingway in Cuba, with Hemingway serving as best man.

With her pale skin, blue eyes, ash-blond hair and trim figure, C. Z. was cut from the same cool, silky cloth as Grace Kelly. She had a patrician beauty that is indigenous to socially registered enclaves like Palm Beach and Southampton, a sporty, outdoorsy look that eschews makeup, hair spray and anything trendy.

Her motto was "The most important thing is to enjoy yourself and have a good time."