SNAKE SKELETONS slither on a cornhusk mosaic in a photograph by Victor Masayesva, a Hopi Indian, in an oblique reference to the Hopi Snake Dance.

But in "Seven Views of Hopi," at the Museum of Natural History, there are no photos of that rain dance where men hold venomous snakes in their mouths. Since 1915, it has been illegal for an outsider of the reservation -- tourist or travel promoter -- to photograph Hopi ceremonials. And Hopi photographers feel restrained as well.

"It is a fact that every Hopi photographer would like to photograph Snake, Flute and Antelope dancers," Masayesva writes. But this would mean "a disregard for everyone, everything . . . the dangerous time prophesied by the old people," he says. "Refraining from photographing certain subjects has become a kind of worship."

And so this show of Hopi photographers is an insiders' view without the inside.

Of the seven photographers, Masayesva is the most eloquent. Poetry accompanies many of his photos, which alternate between portraits of Hopi in traditional dress and scenes of natural decay and death: a flooded field, eroded land and a skeleton whose owner -- a dog? a jack-a-lope? -- was struck by lightning in a pumpkin patch. Similarly poetic is his videotape of life in the mesa country of northeastern Arizona, "The Hopi People, 1981," which lends to the show a backdrop of Indian chants and seasonal activities.

The Hopi are very private people and understandably not eager to pose before every pueblo like human curios. We don't see their "secrets." But here, because one of their own is behind the camera, we do see them at their self-contained ease.

This is especially true in the photos by Owen Seumptewa, who captures not only the timeworn, leathery-skinned old ones, but the young and beautful -- the painted child dressed in paper headdress, the woman barefoot by the potbellied stove, the fairytale princess framed by a window, looking into the twilight for her prince.

SEVEN VIEWS OF HOPI -- At the Museum of Natural History, in the second-floor rotunda, through May.