Luchino Visconti's last movie, "The Innocent," completed shortly before his death in March of 1976, costumes the characters in turn-of-century fashions and locates them in plushly draped interiors of sensuous weight. You feel as if the imagery would be tempting to sink into or recline upon.

Maybe too tempting. "The Innocent" is classy but droopy, definitely the sort of art movie to avoid after a long hard day.Despite a story destined to take hideously melodramatic truns, the movie remains sedate and formal, an aging filmmaker's contemplative swan song.

Even at his best, in epics like "La Terra Trema" and "The Leopard," Visconti was habitually lugubrious. He wasn't necessarily more satisfying when orchestrating lurid effects in movies like "The Damned." Still, "The Innocent" smolders to life only fitfully, and most reliably when Laura Antonelli is unclothed and projecting her specialty, erotic rapture.

The source was an 1892 novel by Gabriele D'Annunzio that was a decadent sensation in its day.Some of the elements that must have shocked its original audience remain vivid. The aristocratic protagonist, Tullio, is a freethinking hedonist who pursues pleasure, urges his devoted wife to abort an illegitimate child, and when the child is born, grows so insanely jealous that he provokes its death by exposing the babe to a chill, on Christmas Eve yet.

According to Visconti, his only fundamental change from the original was to give Aullio enough shame to kill himself for a misspent life. D'Annunzio evidently flattered himself that Tullio was a Nietzschean alter ego whose will could transcend mere mortal laws and conventions. Giancarlo Giannini isn't quite the actor to embody this conceit.

Even in period dress, Giannini looks a bit too wretched and shrimpy to function persuasively as an agitator. The look of the victim or injured dupe still radiates from his overexploited magnetic eyes. The material would probably be more fun for modern audiences if Visconti and his writers had reshaped it as an erotic comedy. One keeps entertaining vain hopes right up until that unforgivable Chrismas Eve.

Tullio and his fellow philandering members of the upper classes seem to be asking for it when they trade remarks about how little it takes to keep their wives happy. While Tullio agonizes over his affair with a liberated widow, Jennifer O'Neill ("I'm a free, broadminded woman who won't share her man with anyone-not even his wife," she sneers, Laura Antonelli is relegated to the music room, where her robust bosom heaves with unfulfilled passion.

It seems a sublime joke on masculine vanity when Tullio is aroused by the thought that his wife has had an affair. Instantly, she's promoted from "dear sister" to desirable sex object.

Antonelli's role may look awfully familiar to moviegoers who've seen her playing another erotic Sleeping Beauty in "Wifemistress," a later Italian film released earlier. She lacks the acting range to project the neurotic symptoms that would have to afflict Tullio's wife after pregnancy, but she's a delectably ripe erotic presence. Visconti gives her dazzling visual entrances and inserts: She suddenly appears in a doorway, her face bathed in sweat, or on a sunny terrace holding a parasol, or peeking over a bedsheet.

The credit sequence anticipates the movie's rather enervated formality in a peculiar way. An aged hand, perhaps Visconti's own, opens a copy of the novel, perhaps a first edition of his own (it's pleasant to think so, anyway), and begins turning over the pages slowly and deliberately. The binding has grown a bit loose and there's crispness left in the pages.

The old book is handled with loving care, but it looks as if it shouldn't be taken off the shelf very often. It might have been more secure and entertaining to handle a new edition.