LATIN AMERICAN fiction today, like the French anti-novel a decade ago, enjoys enormous prestige among academics and writers. Its salient features are frank supernaturalism, social and political comment and experimental form. Carlos Fuentes and Julio Cortazar are among its best known practitioners.

No two men, obviously, can represent a continent. But few United States writers would be likely to give us such stories as these, and these two books begin to define how we and the Latin Americans differ.

Fuentes, a Mexican, has produced the better collection. His scenes draw vitality partly from their vivid sense of place: a Mexico City sprawling and ugly, corrupt and provincial, destroyed by, and destroying, its people. The stories are mined from various literary veins, of which the richest by far is a closely observed social realism.

That is the mode, for instance, of "The Son of Andres Aparicio." Bernabe, the main character, lives in a district of makeshift huts, a barrio so tenuous that it lacks even a name. He quits school and becomes a street hustler, winding up as a thug for a reactionary political gang. Life on the margin -- economic and emotional -- was never made more real, and persuasive connections are drawn between such a life and its political consequences.

But even into this story, so largely successful by any standard, there enters an element that -- I propose -- the Latin Americans like better than we do. This is superimposed design. In a manner too complicated to relate, connections are made at the end between Bernabe's fate and that of his long-vanished father. The effect is completely artificial: human beings are treated, as it were, geometrically. The characters are made to posture so as to describe a pattern.

Still more distressing is the emphasis placed on the eerie. For instance, the story "In a Flemish Garden" is told by a young man serving as care taker in a spooky old house. Little by little, he is enthralled by a supernatural crone. At the end, this person is revealed to be Carlotta, former empress of Mexico; she has mistaken the protagonist for the Archduke Maximilian.

Again: in "Chac-Mool," a man buys the statue of an idol, which comes alive and causes its owner's death. In our own literature, that sort of thing is relegated -- almost always -- to the cheapest of thrillers. To find it at the peak of South American literary fiction suggests, I think, an esthetic rift at whose brink we must stop in wonder.

In spite of all this, we can read most of these 11 stories with pleasure, largely as social portraiture. Fuentes moves with perfect ease from careboard shacks to the palaces of Pedregal, peopling his worlds with generals and mariachis, rentiers and whores. Whatever we think of its extremities, we feel a heart to this collection.

In the 19 stories of Julio Cortazar's new book, a heartbeat is harder to find. Some are set in Argentina, some in Europe, one in Africa. Politics and sexual encounters are the principal subjects; the characteristic act is the lighting of cigarettes, which vanish in smoke innumerably.

Cortazar is fascinated -- I think to a fault, and here the rift may open again -- by manipulation of point of view. Authors everywhere like to begin, sometimes, in medias res, but few of them want the reader to remain so confused for so long. And few play tricks with the identity of their first-person narrators. In "The Faces of the Medal," one of a pair of lovers is telling the story, but we're not to know which: "It's as if we were writing it together . . . in the same way that a medal is obverse and reverse at the same time in the double play of the mirrors of life." This is wearyingly clever.

In Cortazar, as in Fuentes, the supernatural abounds, and here again it seems naive. In "Encounter Within a Red Circle," a woman's ghost turns into a toad. In "Someone Walking Around," a guerrilla has returned to Cuba to blow up a factory, but is strangled by the ghost of the composer Chopin.

Other stories are symbolic, like "Summer." Here a couple whose married life has drifted into dullness is visited one night by a huge, white, menacing horse. The wife is afraid it will get inside their house and crush them. What happens instead is that her husband makes violent love to her, and the horse, which stands for passion goes away.

Still other stories are surreal. In the absorbing "Severo's Phases," we are introduced to a world where death is a spectator sport; the dying person is observed as he goes through such "phases" as sweating and leaping. In one phase, he assigns a number to each looker-on, foretelling the order in which they will die.

Some of the stories are clearly and vividly told -- we know the people, we see the places. In others, though, Cortazar is nearly impenetrable: his sentences run 500 words, his paragraphs extend for pages. When you finally, as it were unpack the story, extricate what's being told from the entanglement of its telling, you are struck by the disproportion of means to ends. By contrast with its billowy wrappings, the story seems ludicrously slight.

The Fuentes is translated by Margaret Sayers Peden, the Cortazar by Gregory Rabassa, and both books read smoothly. It is slang that comes hardest; English equivalents -- including hippie jargon -- often seem, in the mouths of Latin Americans, to strike the wrong tone. But the largest problem is translation itself; it conveys information wonderfully, but not literary effect. It meets its limits when a passage turns upon the coloration of a verb, a noun with several meanings, the falling music of a final phrase.