TELEVISION

* THE KENNEDYS OF MASSACHUSETTS (ABC, SUN., FEB. 18; MON., FEB.19; WED., FEB 21; 9-11 P.M. EACH NIGHT)

We all know that, ''Lonesome Dove'' aside, long miniseries are supposed to be out of fashion. This one, about the early years of a family that has been subjected to a lot of TV-movie exploitation, has been in the works for years, and was cut almost in half from its original 11 hours. So it seemed that The Kennedys of Massachusetts would have to be a botched job, a dreadful drag.

Instead, over its three days, the miniseries delivers the week's most affecting drama and best acting, with William Petersen and Annette O'Toole offering remarkable detailed, unsparing portrayals of Joe and Rose Kennedy, the couple who built Camelot for their kids. Based on Doris Kearns Goodwin's book ''The Fitzgeralds and the Kennedys,'' the movie is like ''The Brady Bunch'' with brains and Boston accents. We watch the youthful Joe Jr., John, Rosemary, Kathleen, Eunice, Patricia, Robert, Jean, and Ted grow up and meet their fates. But ''The Kennedys of Massachusetts'' stops when John becomes President; here, it's the parents who matter.

Until now, William Petersen has pursued a career as a thoughtful action-hero in such movies as ''To Live and Die in L.A.'' and ''Manhunter''; his complex, devious, grinning family-man Joe Kennedy is thus a complete departure for him, and so utterly successful that Petersen is at first unrecognizable in the role. Annette O'Toole, on the other hand, has managed to elude stardom by taking unsympathetic roles in such films as ''One on One'' and ''The War Between the Tates.'' Her grim, unyielding Rose Kennedy is therefore entirely in keeping with O'Toole's brave lonely career.

Much of the credit for the artistic success of ''The Kennedys of Massachusetts'' must go to director Lamont Johnson, who does something rarely attempted in historical TV movies: He leaves in the politics. Joe and his obstreperous brood discuss isolationism, prejudice against Irish Catholics, and New Deal democracy around their dinner table. Even if you don't believe the conversation could possibly have been as lively and articulate as it is here, it's still solid, thought-provoking chatter. A-

* THE DEATH OF THE INCREDIBLE HULK (NBC, SUN., FEB. 18, 9-11 P.M.)

They should have called this ''The Incredible Death of the Incredible Hulk'' -- who's going to believe that Bill Bixby would kill off his annual chance for employment? Bixby, who also directed and coproduced, does his usual David Banner shtick, whispering his lines slowly, so they all sound profound, and staring soulfully at everyone to convey the terrible burden of his overdeveloped, emerald alter-ego. (And speaking of the Hulk, this time around poor Lou Ferrigno has been handed an inexplicably poor wig to wear -- instead of wild Hulk hair, it looks as if an oat-bran muffin is growing out of his head.)

But I'm procrastinating. You want to know, does he really die? Well, I don't want to give too much away, but... oh, heck, yes, I do: At the end of the show, the Hulk falls out of an exploding plane full of terrorists, hits the pavement awfully hard, turns back to David Banner, says, ''I'm free,'' and closes his eyes; fade to black. In other words, it sure looks as if he's a goner.

But then again, we're talking superheroes here. We're talking a series that once featured the Mighty Thor as a special guest. I'm betting the next time you see Bill Bixby on television, it'll be about a year from now, in ''The Resurrection of the Incredible Hulk.'' D

* ONE SECOND BEFORE SUNRISE: A SEARCH FOR SOLUTIONS (PBS, SUN.,FEB. 18, 10-11 P.M.)

On horseback, host Lynn Redgrave gallops at a fierce pace down a steep hill; she reins in her mighty steed and shouts, ''I'm Lynn Redgrave, and I'm one of 5 billion people in the world.'' Well, so am I, Lynn; what the heck is your point? Redgrave's point is that the human race will be in for big trouble unless we do something about protecting the environment, and One Second Before Sunrise details a number of projects to do just that.

For example, Redgrave goes to the Amazon Basin, where Peruvian agriculturalist Juan Guevara is managing to stave off further destruction of the rain forest and improve the standard of living by introducing the ideas of fish-farming and the purification of river water for drinking. The actress moves on to a ghetto in the Bronx, where Gary Waldron, a former executive at IBM, currently spends his time cultivating gardens and building greenhouses on that barren landscape.

Redgrave globe-hops, locating and celebrating other such noble efforts. But ultimately, the stories Redgrave has to tell are more depressing than inspiring,because they imply that governments all over the world care so little about major environmental and economic problems that it's left to a few hardy souls to do something -- and their efforts are necessarily limited. Redgrave is chipper, her questions more pointed and more intelligent than most of what passes for television reporting. But in the end, ''One Second Before Sunrise'' is one dismaying little bummer. C

* EYES ON THE PRIZE II: A NATION OF LAW? (PBS, MON.,FEB.19, 9-10 P.M.)

So far, Eyes on the Prize II has been much more uneven than its predecessor; that's because public television apparently can't figure out what tone to take toward the more militant civil-rights movements and tumultuous events of the late '60s and early '70s. It's easy to speak approvingly of Martin Luther King Jr.'s nonviolence, but what abut Malcolm X's ''by any means necessary'' slogan for black survival?

The problem is highly evident during this hour, which is framed by two events: the killing of Black Panther Party leader Fred Hampton by Chicago police in 1969 and the 1971 uprising at New York's Attica State Prison, a protest bloodily suppressed by police and state troops under the orders of then Gov. Nelson Rockefeller. Television long ago succumbed to the notion that all depictions of violence must be broadcast with a tone of harsh disapproval. So it is difficult for ''Eyes on the Prize II'' to distinguish between, say, the violence of the authorities at Attica and what Malcolm X, Stokely Carmichael, Fred Hampton, murdered Panther and San Quentin inmate George Jackson, and many others were trying to accomplish in the name of self-defense and black pride.

Many people today, when they think about these events at all, probably would hold that the Panthers were violent and wrong-headed, and that Attica was tragic but inevitable. But, thrillingly, the visuals in ''A Nation of Law?'' -- the shocking news footage from that period and recent, moving interviews with the survivors of the era -- contradict such complacent attitudes. Merely by reminding us of that period of history, ''A Nation of Law?'' stirs up exhilarating ideas, arguments, and emotions.

This period inspired a remarkable amount of first-rate journalism, most notably the shamefully neglected book ''Who Killed George Jackson?'' by Jo Durden- Smith. (Anyone who admires ''Eyes on the Prize II'' should seek it out.) Almost despite itself, ''A Nation of Law?'' can now take its place in that company, as TV journalism of the most powerful and essential sort. A

* MONTANA (TNT, MON., FEB. 19, 8-10 P.M.)

It is a big week for opening shots on horseback: First Lynn Redgrave digs her spurs into a thoroughbred on PBS, and over theopening credits of TNT's Montana, Gena Rowlands guides a big brown horsie down a rocky slope. Rowlands hoists a rifle and, still loping along, shoots at a truck that's trespassin' on her spread.

Gena Rowlands as a cowgirl? Somewhere in heaven, her husband, the late John Cassavetes, is laughing that great, raspy laugh of his. In ''Montana,'' Rowlands plays Bess Guthrie, who runs a vast ranch in present-day Montana with her ornery, scraggly, drunken, no-account husband, Hoyce. He's played by a miscast Richard Crenna.

Ludicrous miscasting is, in fact, the chief pleasure to be drawn from ''Montana.'' Crenna, who is ordinarily a fine, understated actor, goes unaccountably loopy here, limping around like Chester from ''Gunsmoke,'' chawin' tobaccy, and getting rip-snortin' snokkered in the local saloon. Crenna's best scene comes early on, when he takes part in a local custom: lassoing neighborhood Indians as they ride by on motorcycles. ''Ropin' Injuns,'' Crenna calls it, and if this sounds cruel and condescending to Indians, I haven't told you about the huge knife one Indian pulls out to exact revenge on Crenna. In ''Montana,'' everyone gets to behave equally badly.

This is the first teleplay by Larry McMurtry since his glorious ''Lonesome Dove,'' but not really: You see, ''Montana'' was written at least a decade ago, and only now, in the wake of ''Dove,'' has McMurty's script been produced. ''Montana'' doesn't exactly have the spirit and vision of ''Lonesome Dove,'' it's more like an episode of ''Dallas,'' if J.R. were an inebriated bum. The plot is resolutely predictable: Crenna and Rowlands have to fight to deep their ranch from being taken over by some mean old oil drillers. McMurty has made his reputation refuting the clichés of the Western: here, he succumbs to them. C-

* ALIEN NATION (FOX, MON.,FEB. 19, 8-10 P.M.)

This is the very special episode in which a new alien baby joins the show's alien family, and, as always with Alien Nation, the supposedly surprising, profound plot twists are utterly predictable.

In the world of these so-called Newcomers, it's the man who gives birth. Stop it, stop it -- you're blowin' my mind, you crazy Fox network! Lot's of jokes are made here about how pregnant alien policeman George (Eric Piermont) has swollen ankles, his back is killing him, and his taste buds are wonky (''I used to love the smell of tripe -- now I can't stand it''). His pals throw him a baby shower, and he starts sobbing about how fat and unattractive he is.

Still, despite the corniness of everything that precedes it, I would be sure to tune in for the last five minutes, when George actually has the baby. He gives birth prematurely (of course), and his human cop partner, Matt (Gary Graham), has to deliver the baby (of course). The thing is George's labor is surprisingly intense and gratifyingly, realistically yucky for network television, and the baby is as cute as the dickens. Hey, do you think if the ratings go through the roof with this episode, ''Married... With Children'' will do a dream sequence with Al Bundy having a baby? C+

* AMERICAN PLAYHOUSE: IN A SHALLOW GRAVE (PBS, WED.,FEB. 21, 9-11 P.M.)

This adaptation of the James Purdy novel errs on the side of faithfulness; it seems as if every overwrought emotion, every overblown speech that Purdy managed to make believable in his prose has been brought to the small screen, which simply cannot contain that much florid lyricism.

In a Shallow Grave is about Garnet (Michael Biehn), a young Marine whose face was disfigured in a World War II battle. He strikes up a friendship with a handsome young drifter (Patrick Dempsey), who agrees to deliver the letters Garnet writes to a neighborhood woman whom he loves but is too self-conscious to meet. As a character, the woman (Maureen Mueller) is little more than a vague abstraction; it is the relationship between Garnet and the drifter that provides the story's central drama.

As overseen by director Kenneth Bowser, ''In a Shallow Grave'' doesn't work. It moves at a crawl, for one thing, and Garnet's disfigurement isn't really all that unsightly. Maybe it's just this crazy ''Beauty and the Beast'' time that we're living in, but Garnet's lumpy, mottled visage doesn't seem repulsive. It's inadvertently funny when Bowser has scenes of people literally throwing up when they see poor Garnet. And funniness was one quality Purdy wasn't going for with his story. C

* SMITHSONIAN WORLD: A MOVEABLE FEAST (PBS, WED., FEB. 21, 8-9 P.M.)

The normally stately ''Smithsonian World'' has tried to liven things up by hiring Linda Ellerbee's production company to make its television debut with a fast-paced look at how humans have fed themselves through the ages. A Moveable Feast begins in 1627 in Plymouth, Mass., as an actor dressed up like Gov. William Bradford talks about the food his young colony is harvesting. It's jaw-droppingly dull.

Writer-narrator Lloyd Dobyns, Ellerbee's former NBC News pal, then guides us through the history of American food manufacturing, culminating, of course, with McDonald's restaurants. Along the way, the formerly witty Dobyns writes himself narration such as this: ''What did the Dutch add when they settled in the Northeast? What else? Cheese...''

Oh, cheez, Lloyd. D