MOSTLY the "Stolen Treasures--Missing Links" exhibit at the National Geographic Society hall is about archeological piracy in Peru and other places. But the show--which lasts all this year--has something else: a wonderful pile of pre-Inca pottery.

If you thought pre-Columbian art consisted of square snakes and people having their hearts cut out, if you never want to see another jade skull with real teeth, if you are up to here with cute little models of Aztec priests wearing someone else's skin, then this is definitely the show for you.

There are smoothly turned bowls, outrageously shaped and elegantly decorated, dating back to the Chavin cult of 900 B.C. There are nesting birds, pelicans awaddle, hummingbirds, whales. There are frog pots, clay parrots, cats, monkeys, crabs. There is a delightful model of a scooped-out half-pumpkin with a row of small birds perched on the edge peering in.

From the Moche culture of around 300 A.D. come portrait busts of handsome and intelligent people, rational and even benign, refuting the monstrous rage-masks favored by the Mayans and others. This head could be a Renaissance Italian merchant complete with rimless hat. That droll person seems to be chewing some pleasant leaf, because he is clearly zonked out of his mind.

The Nazcas of about 100 A.D., the people who made those vast mountain-plateau drawings readable only from hundreds of feet in the air (inspiring one pop science writer to claim they had been visited by art critics from outer space), also created charming animals from clay, including a cat demon with white tiger-whiskers and rolling eyes.

Works by other tribes are shown here, from the Paracas of 400 B.C. to the Huari of 600 A.D. and finally the Chimu, who settled the great city of Chan Chan, sprawling over 12 square miles in north central Peru, probably the biggest city in South America before the Incas conquered and centralized the whole country.

One would love to know more about the Moche bean runners, depicted on a vase: a privileged class, rather like Samurai, they may have been precursors to the Inca chasquis, those relay runners who became a communications network for the whole empire, evidently as part of a ritual activity. You thought running was big today.

In any case, the obsession with death and pain that seems to have dominated the great conquering tribes, the Incas and Aztecs, cruel people with cruel gods, is hardly visible in this show, which includes a few obligatory bits of gold jewelry but consists almost entirely of pottery. It will make you smile.

One of the big National Geographic-type photos accompanying the show is of a man wearing the famous Totonac grin, which has baffled scholars for centuries. This grin exists only in Totonac sculpture, from the Veracruz area.

The figure is billed as the god of pulque. Pulque is distilled from the agave plant. It looks like dishwater and tastes like coconut milk, but you'd better be sitting down if you're having more than one. Anyway, that would explain the grin. CAPTION: Picture 1, Found on the north coast of Peru, this stirrup-spouted bottle was traced to the Moche culture of about 250 A.D.; Picture 2, A double-spouted bridge bottle. Photos by Victor R. Boswell Jr., copyright (c) 1983, National Geographic Society