Saturday night. The New York Post's James Brady, who was standing next to author Jerzy Kosinski, who was across the room from Barbara Walters, who was just a canape tray away from Woody Allen, stood surveying the celebrity-packed living room of Gil and Susan Shiva's flat at The Dakota.

"You know someone called me this afternoon to ask why I was coming to this party when I knew it was going to be such a mob scene," mused Brady. "So I said, 'of course, it's going to be a mob scene, but at least it's the right mob.'"

Two years ago Italian director Lina Wertmuller took New York by storm. Her films "Swept Away" and "Seven Beauties" opened to rave reviews. Critics were hailing her as the new ancienne terrible of the film industry. Everyone wanted to meet her, and did, during a series of parties.

Last weekend Wertmuller returned to the scene of her triumph accompanied by her latest film. "Night Full of Rain," starring Candice Bergen and Giancarol Giannini, which many reviewers think is awful. Including John Simon, whose praise for Wertmuller has been known virtually to ooze.

("I admire her work, but not this one," is how Simon put in Saturday night.)

Nonetheless, a party was in order. So Shiva, the film's executive producer, along with his wife, Susan (daughter of Jules Stein), threw it - just as they had done the last time Westmuller was in town. And just like that last time, almost everybody - 250 or more - who was anybody showed up.

"Vanity brought us all together here tonight," said Kozinski as he stood chatting with Norman Mailer. Mailer, who bemoaned the absence of his social sparring partner. Gore Vidal, arrived with girl friend Norris Church, five months' pregnant, who said that if Mailer has his way - and he usually does - he will be delivering this baby himself at home.

Earlier, while celebrities waited downstairs for what might be the slowest elevator in New York, the paparazzi had a field day. "If you have to photograph me, this must be a terrible party," said gossip columnist Liz Smith, whose arrival elicited a blinding blaze of flashbulbs. Socialite and girl-around-town Barbara Allen, however, didn't seem to mind posing for photographers even though she was later heard to remark that "such a ridiculous amount of paparazzi is really so boring."

Upstairs, Wertmuller herself barely got past the foyer, where Shiva launched her toward endless introductions - an ordeal Wertmuller bore with charm and vivacity. "Yes, yes, yes, this is a wonderful party," she said, adjusting her trademark white glasses. "Very interesting, very active, but I wouldn't want to do this every evening you understand."

Wertmuller, who was dressed mostly in jewelry, sported among other things seven necklaces, two of which dropped to the navel, two pierced coral earrings per ear, and a gaggle or rings, one of which stretched to her wrist to form a bracelet.

As for negative reviews, Wertmuller appeared unperturbed. "I believe very much in this picture. It is a very big hit in Italy already. I am curious for the reaction of the public, for they will be the ones to decide.

"Giancarlo is wonderful and so is Candy. You know why I pick Candy for the role? Because she is a very typical face of America."

A few feet away. America's typical face wore something of a pained expression as she stood making small talk, dressed in satin blouse and pants. "I'm readly, not much of a party person. Right now, I feel a bit like my face is starched." She had some of the same reservations about her movie. "I like a lot of the movie, but I think it is not accessible to some people, even though it does say some important things about relationships. But I know I'll get shot in the reviews. I'm resigned to usually getting creamed, so I'd be surprised if I didn't."

Meanwhile, her co-star Giannini wandered around the party looking smaller, thinner and even more droopy-eyed than he did on the screen. Reminded that the last time he partied at the Shivas his blue eyes had locked with those of then-single jet-set model Marisa Berenson and stayed locked for several week thereafter Giannini smiled nostalgically, "Ah, yes, that ended, but that's life, no?" No. Or at least maybe not. Told that Berenson recently separated from her husband, tycoon Jim Randall, his nostalgia seemed to vanish. What? You are sure? What news."

The party itself was a traveling affair. Guests rambled from living room to bedroom to buffet rooms where there were round tables to seat those helping themselves to a continuous buffet of ginger chicken, tortellini, chili, salad, an assortment of cheeses and fresh strawberries. "If you tear down the walls of this place you could put a Boeing 747 in here," remarked author Gay Talese, who said his long-awaited book on sex in America is scheduled to be published this spring.

Marion Javits, an occasional visitor to Washington, where her husband is employed, arrived with Egon von Furstenberg, but said she would in fact be in Washington this week to throw a "small dinner party for Zbig," (Brzezinski, that is). When asked by one guest to evaluate Carter's Washington. Javits said she fould it "packed with too many kids and unknowns, Carter ought to take a look at the people surrounding him. I like the looks of a Califano or Zbig, of course, but the rest aren't too stimulating, are they?"

The same might be said of Woody Allen, hardly known as the life of the party, who Saturday night was making no attempts to alter that image as he ducked behind chairs, people and plants to avoid not only the press, but people in general. (The waiting paparazzi so unnerved Allen that he asked to be let in through the basement).

Andy Warhol maintained his public image as perhaps America's oldest-yet-still-star-struck celebrity by pronouncing the party "great. Everybody in this room is somebody." Warhol, who arrived in black tie with Bianca Jagger in red dress, spent most of the evening flashing the lid from a Smucker's grape jelly jar, which he said was a gift given him just that night.

Farrah Fawcett-Majors, scheduled to show up with her bodyguard never did appear, host Shiva said that he really didn't think it made any difference. On the other hand, Rolling Stone editor, Jann Wenner, no slouch as a celebrity hanger-on, seemed positively giddy wandering among guests such as Jules Feiffer, Random House publisher David Obst and wife, Linda. New York magazine editor Joe Armstrong, Rex Reed, former NBC president Herb Schlosser, Lauren Bacall (who said she didn't think it was such a big-name group) Shirley MacLaine, who arrive with New York pol Andrew Stein, Carrie Fisher, Dick Cavett and wife, Carrie Nye, Yasmin Kahn, socialite Delfina Ratazzi, and Neal and Leba Sedaka.

Socialite Jan Cushing arrived with director Jerry Schatzberg, who said he, too, was on his way to Washington to scout locations for his upcoming film. "The Senator" starring Alan Alda in the title role "We just signed Barbara Harris today to play the wife," said Schatzberg. "And now we have to get a mistress. What do mistresses in Washington look like any way?"

At one point, Liz Smith looked around the room and remarked. "In a party full of publicity bull - like this, the only interesting people are (archeologist) Irish Love and Norman Mailer."

The party, which started at 9, finally thinned out around 3 when Giannini and an entourage of Italians, guests of Wertmuller's, headed for Studio 54 to end the night. Wertmuller said she was not going. "I am going to take my husband, Enrico (Job), and go home and go to sleep. To party is more exhausting than making a movie."