MIGUEL COVARRUBIAS twisted a line and it was a nose, a profile, and more. Covarrubias' caricatures absorb the viewer in their genius. The Portrait Gallery is displaying 84 of these linear delights. Most belong to the Prints and Photographs Division of the Library of Congress, and many have never been published.

Coming to New York from Mexico City in 1923 at age 18, Covarrubias immediately took America by storm with his exaggerated portraits. Within a few years he was to fill pages in Vanity Fair, Vogue and The New Yorker.

Soon after his arrival, Covarrubias shared a studio with caricaturist Al Hirschfeld. In his catalogue essay, Hirschfeld attributes Covarrubias' "thinking in line" partly to his stay in Bali -- the southern sun etching deep lines and shadows -- and to pre-Columbian art.

In his caricatures, certain strangeness or eccentricity, distinctively Covarrubias, coexists with the undeniable reality of the dancers, novelists and other glitterati he depicts.

He was a Picasso who chose to leave the nose in place.

With Covarrubias, less is more. Minimal lines and hatchings form the orange-slice grins, the mustaches longer than life, the half-moon brows. They're more woodcuts than drawings.

His treatments of the personalities of the Depression and the Jazz Age in New York were not by any means subtle. Authors got the worst of it. Dressed in coveralls, Theodore Dreiser is "President of the American Fiction and Construction Company." Faulkner wears rompers with bucket and shovel, in case he finds dirt to dig in his playground. Hemingway pours hair-grower on his chest.

"Impossible Interviews" are the high point of this show -- and possibly of Covarrubias' career as a caricaturist. (He was also an anthropologist, but that's another story.)

In the 1930s, Vanity Fair published a number of unlikely encounters between famous people; there are 17 in the show. Sparked with satirical dialogue (excerpted on the exhibit's labels), the "Impossible Interviews" are witty, urbane and absurd. One finds humorist Will Rogers (haw, haw, haw!) marooned on a raft with sophisticated playwright Noel Coward (heu, heu, heu!). Jean Harlow, shapely in white on a psychoanalyst's couch, toys with a dark and pensive Sigmund Freud. And angular modern dancer Martha Graham meets fan dancer Sally Rand, wearing a smile and a seven-foot ostrich feather.

In a sense the drawings show popular assumptions, or outline merely the masks worn by celebrities. But, as Covarrubias' contemporary and another talented draftsman, Ralph Barton, observed:

"It is not the caricaturist's business to be penetrating; it is his job to put down the figure a man cuts before his fellows in his attempt to conceal the writhings within his soul."

MIGUEL COVARRUBIAS CARICATURES -- At the Portrait Gallery through January 13, 1985.