NEW YORK (AP) _ The richest of the rich in America is worth $2.8 billion, while the poorest of the rich checks in at a mere $150 million. But who's counting?

Forbes magazine, for one, and its 1985 list of the nation's 400 richest people is topped by Sam Moore Walton of Bentonville, Ark., who has made $2.8 billion through his Wal-Mart discount stores.

Walton, who danced a hula on Wall Street last year when profit goals were met, replaced Gordon Getty, the front-runner for the past two years. Getty dropped to 15th.

Getty's fortune was $4.1 billion last year, but he agreed to divide the family oil trust with other family members, leaving him barely $950 million.

Second place went to H. Ross Perot of Dallas, founder of Electronic Data Systems, who was $1 billion behind Walton.

Media holdings were up this year, making billionaires of John Kluge and S.I. and Donald Newhouse and adding newcomer Rupert Murdoch, whose publishing empire has earned him $300 million.

Agriculture and oil were down. Seven Texas oilmen who appeared last year were dropped from the list. So were four Rockefellers and 53 others.

Eight Rockefellers remain on the list, along with the usual number of Cabots, du Ponts, Hunts, Hearsts and Kennedys.

There also are beermakers Busch, Coors and Stroh and vintners Gallo. Robert Guccione, publisher of Penthouse magazine, is on the list with $220 million, but Hugh Hefner of Playboy is not.

Among the rich and famous are Gene Autry, the cowboy star, who has made $150 million in broadcasting and real estate; Ted Turner, the rambunctious Atlantan, with $300 million; and Norman Lear, who brought the nation ''All In The Family,'' and has $175 million.

The list, to appear in Forbes' Oct. 28 issue, provides a fascinating portrait of the rich in America.

The average net worth of the 400 is $335 million. There are 14 billionaires. Only 165 built their fortunes without significant inheritances.

Fourteen are immigrants and 78 are women. At least eight did not finish high school.

Forty-one of the men and 38 of the women are unmarried. And 113 have been divorced.

Most of the rich are not very famous.

James Jaeger, at 37 the youngest of the self-made rich, earned $175 million with automotive radar detectors. Max Palevsky, 61, is a computer designer who made $200 million. Philip Hampson Knight used to sell sneakers. He still does, in a way. He owns $195 million worth of Nike.

At the top of the list is the 67-year-old Walton, who gained his fortune by building 745 discount stores mainly in small Sun Belt towns. Walton and his family owns 39 percent of the business, which produced $6.4 billion in sales last year.

Walton opened his first Wal-Mart in 1962. ''We believe in having fun in business,'' he says, and has been known to lead cheers at company pep rallies.

Walton lives modestly in Arkansas, where he drives an old car, hunts quail and has his morning cup in a local coffee shop. He is married and has four children.

Perot, 55, of Dallas, was fourth on the list last year and moved to second with $1.8 billion.

In all, 14 people - 12 men and two women - are worth at least $1 billion, compared to 12 billionaires on Forbes list last year.

David Packard, the 73-year-old chairman of Hewlett-Packard, was third with $1.5 billion. Margaret Hunt Hill of Dallas, who inherited money from her oilman father, H.L. Hunt, was fourth with $1.4 billion.

A second of H.L. Hunt's daughters, Caroline Rose Hunt Schoellkopf, 62, was fifth with $1.3 billion. Samuel I. Newhouse Jr., 57, and brother Donald Newhouse, 56, share a $2.2 billion fortune.

Seven others are worth at least $1 billion: David Rockefeller, 70, of New York City; Henry Lee Hillman, 66, of Pittsburgh; John Werner Kluge, 71, of Charlottesville, Va.; Harry Helmsley, 76, of New York City; Marvin Davis, 60, of Denver and Beverly Hills, Calif.; Warren Edward Buffett, 55, of Omaha; and Leslie Herbert Wexner, 48, of Columbus, Ohio.

The 400 richest people in America range in age from 28-year-old Abby Rockefeller Simpson of New York City, with an inherited $200 million fortune, to 93-year-old Dorothy Bullitt of Seattle, worth $275 million from broadcasting. The average age is 62.5 years.

More than half live in six states: 80 in New York, 49 in California, 44 in Texas, 23 in Florida, and 21 in both Delaware and Illinois.

Among those who did not make the list was New York publisher James Haller Ottaway Sr. With a fortune worth $147 million, he was 401st.