It's easy to understand why the prolific Auchincloss (East Side Story
) has been hailed as a "Living Landmark," writing as he does about a mannered New York of bygone days. His latest book, a collection of six stories, doesn't stray from this familiar, still fertile ground, with mixed results. The title story's narrator, a retired English teacher from a tony Manhattan school for "young ladies," recalls his three favorite pupils (class of 1937); in detailing his involvement in their lives as they grow into adulthood, marriage and motherhood, he reveals just how far he will go to remain a confidant and friend. A New England prep school provides the setting for a contest of wills between a young priest and a tyrannical headmaster in "The Devil and Rufus Lockwood," and a different clash of personalities is on display in "The Country Cousin," a light, predictable drawing room comedy of manners fashioned as a one-act play. Class conflicts, anti-Semitism and McCarthyism needle the WASPy characters, and personal transformations take place against the changing meanings of marriage and shifting social mores. Though there are few surprises and the waters aren't deep, Auchincloss turns over his own turf with consistent charm. (Mar.)