A.R. GURNEY JR. is pretty much our sole exponent of the gentle drawing room comedy--that literate, eminently civilized (and civilizing) theatrical entertainment that once flourished on the Broadway stage but has been largely drummed out of existence by the flash and hurly-burly of the commercial grind.

"The Golden Age," Gurney's latest endeavor, which opened a five-week run in the Eisenhower Theater last night, will remind you of what we've been missing. Or would be missing, if Gurney weren't around to muse about manners and mores, about the transmission of culture from one generation to the next, about the sweet, siren call of the past, with all its seductions and perils.

Juggling time and characters, Gurney explored this territory in "The Dining Room," structurally a far more inventive play than "The Golden Age." In this one, the playwright is content to tell his story from leisurely start to quiet finish. But it is a beguiling story, warm and humorous, and it is superbly acted by Irene Worth, Jeff Daniels and Stockard Channing. If there is a place for plays that assume the intelligence of an audience and proceed from there, for dialogue that does not feel obliged to go for the jugular and for creatures who are not racked with neuroses (just the quirks and eccentricities that once made for something called character), then "The Golden Age" deserves to occupy it.

I found it wonderfully pleasurable in the way that a winter fire is pleasurable, when the friends nearby are good and the conversation alert.

Gurney has set his play in a grand New York brownstone on 83rd Street, inhabited by a reclusive octogenarian with a colorful past and a mousey granddaughter with a touch of dipsomania. The old woman, Isabel Hastings Hoyt (Worth), was one of the glittering presences of the jazz age. Freud sent her cigars, Cole Porter wrote a song about her (to which T.S. Eliot supplied additional lyrics) and Trotsky once gave her a case of brandy as a house gift. Even more to Gurney's point, F. Scott Fitzgerald may have lodged in an upstairs bedroom, may have had an affair with her and just may have been inspired to write about it in a long-lost chapter from "The Great Gatsby."

That, at any rate, is why Tom (Daniels), a well-scrubbed journalist and part-time teacher of American literature, comes knocking at the door. The world may have forgotten Isabel Hastings Hoyt, but he hasn't. Here--in the form of a silver-haired grande dame with rich memories and untold secrets--is the stuff for the article, or the book, that will make his name. She knows what he's after. But she's too much a woman of her own mind not to know just what she wants, too--someone to bring her granddaughter Virginia (Channing) out of her shell, court her, marry her.

Like an elegant spider, the old lady lures the journalist into a tantalizing web of demi-revelations and half-truths, always intimating, but never confirming, the existence of the precious Fitzgerald manuscript. Once an actress, she has never forgotten the actress' ploys. The past may be her bait, but she uses it to shape the present. Her mystery is that of the elusive courtesan; her goal is that of a very determined matchmaker.

It is a splendid role and Worth plays it splendidly--with a flirtatiousness and elegance that contain just a seed of duplicity. Who wouldn't come under her wiles? Coaxing the journalist into a dance, she casually lets it drop that Irene Castle taught her this particular dip, and then proceeds to demonstrate it to the scratchy strains of "Poor Butterfly" emanting from the Victrola. All very matter-of-fact. Didn't Irene Castle teach everybody? Worth's trick as an actress--and it is a considerable one--is not to accent the extravagance and color. Instead, she makes them second nature, part of her charm, but no more so than, say, the fine profile she's lived with all her life. The only element missing from the performance right now is a certain frailty. Worth occasionally allows herself to be entirely too vigorous for 80.

Red of nose and ratty of hair at the start, Channing pulls off one of those ugly duckling transformations with great dexterity, and by the end she gives every indication that she is her grandmother's granddaughter. The characterization is self-effacing without once disappearing into the lilac wallpaper--also a smart trick, if you can manage it. Few actresses can. And with his shock of blond hair and his nice-guy looks, Daniels makes a most appealing intruder into this closeted world, an eager beaver who realizes he's got to remain cool and polite on the outside, even while his curiosity is exploding.

John Tillinger's trusting direction is the best kind--content to support the play's subtleties, instead of forcing them, and willing to let the spell come at its own pace. For the work ultimately does exert a palpable spell, apt to seduce all those who do not demand that their plays unfold to thunder and cymbals. Looking back with nostalgia, Gurney hears the intimate echoes of a fabulous age. But being a man of some realism, he recognizes that echoes are merely the leftovers of time. Using her magical past as a tool and even a prod, the heroine of "The Golden Age" ushers her two young charges triumphantly into the here and now.

THE GOLDEN AGE. By A.R. Gurney Jr. Directed by John Tillinger. Scenery, Oliver Smith; costumes, Jane Greenwood; lighting, Arden Fingerhut; with Irene Worth, Jeff Daniels, Stockard Channing. At the Kennedy Center Eisenhower Theater through Oct. 15.