Five men with shaved heads, doused in powder to their toes and dressed in little else, performed an hour-and-a-half ritual last night at the Warner Theater. Sankai Juku is in town again and, as on this Japanese group's first visit a year ago, the seriousness of the dancers and the simplicity of their work held a well-filled house almost spellbound through seven scenes (without intermission). At the end, there was walloping applause from the dance-plus-art audience.

"An Homage to Prehistory" is the subtitle of "Jomon Sho," the piece being shown on this visit (which lasts through tomorrow night). Each scene, though, suggests events that occur in the life of any individual and every civilization. And as layers of meaning accumulate, the hairless pallor and powdered nakedness of the bodies on stage come to seem necessary.

The dancers appear repulsive at first. Posed in pools of light, they look like suspended embryos. As they begin to move, with extreme articulation of the fingers, wrists and elbows, they become cadavers demonstrating skeletal flexibility. Gradually a veiled sensuality emanates from their actions. At last, though, the blankness of these bodies becomes as utilitarian as a white mask on which one can paint a clown's grin or a geisha's smile and then easily erase it again.

Pose is often more important than movement in Sankai Juku's dancing. The stance is highly tensed. Motion often seems more a letting go than an asserting of oneself. Even at its freest, though, it's never wild. Relaxed gestures, steps or shifts of torso are disciplined by repetition or spatial range.

The five men aren't equals. Goro Namerikawa, Keiji Morita, Atsuhi Ogata and Toru Iwashita are acolytes. Ushio Amagatsu is the priest. He's not only the choreographer for Sankai Juku, but he dances as a soloist. In slow motion he's masterful, and when he stops moving the impulse doesn't seem throttled but merely held back for the time being. Perhaps the finest moment in Amagatsu's performance is a passage of silent mouthings. The intensity of his feelings is all the stronger because no voice defines them as being moans of pleasure or groans of pain.

Amagatsu's use of space is as simple and subtle as his use of bodies. In the "symmetry scene," two large metal rings represent mirrors. They are not identical mirrors, though. One reverses right and left normally but flattens the dancers' bodies as in an Egyptian frieze, while the other mirror reverses up and down, forward and backward.

Japan and its theatrical heritage of forms, realistic details and emotional colors are the chief sources of Sankai Juku's choreography and stage and light design. Other performers of this new/old expressionist movement theater, which the Japanese call "Buto," owe greater debts to such alien traditions as German modern dance and western minimalism. If there was a foreign ingredient showing yesterday, it was probably a German-modern forcefulness of mime. Yasukazu Sato's music skillfully blended old Japanese timbres and electronic surges.

Lacking in Sankai Juku is room for frivolity. If the action had called for laughter, it would have had to be laughter seriously imitated. The whole attitude is too religious to allow lightness of tone, an ironic manner or play for play's sake. Those who think that art ought to be reasonably mad won't approve of Sankai Juku.