NEW YORK (AP) - "Looks familiar, doesn't It?" Jean Shepherd inquires as he guides his skiff toward the thick, dark slime of the Okefenokee Swamp. "That's where we all came from, the primordial ooze." Shepherd has a knack for summarizing a circumstance, like the origin of life, in a fresh, pithy and eminently funny way, and he doesn't seem fazed by the news from California that life may have emerged from clay, and not mire. The Times (New York, where Shepherd read of the theory) is always killing your dream," he says. ''So much for the swamp, yeah!" Shepherd - writer, actor and keen observer - is a bearded national treasure, and if time is money, his half-hour show, "Jean Shepherd's America," is worth a million. It's a return to public TV for Jean Shepherd's America." First broadcast in the 1971-72 season. It begins this week on WDCN - Channel 8 and will air Tuesdays at 7 p.m. The new set includes 10 original productions, beginning with "Mosquitoes and Moon Pies" from the Okefenokee, and three from the previous series. Shepherd has done several things for public television since the series' first run, including "Phantom of the Open Hearth" for ''Visions" and "The Great American Fourth of July and Other Disasters" and ''The Star-Crossed Romance of Josephine Cosnowski" for American Playhouse." He has a novel coming out in October, based on his experiences in the Army, and at least three paperbacks in print, including "A Fistful of Fig Newtons," "Wanda Hickey's Night of Golden Memories," and "In God We Trust, All Others Pay Cash." Shepherd's work Is not necessarily autobiographical, though it does have that overtone. Some of it is set in Hohman, Ind., across from Chicago, which probably is Hammond. "My father was a cartoonist for The Chicago Tribune," he explains. "He looked like Clifton Webb. No, I would say he was a cross between Jack Nicholson and Paul Newman. He was always very elegantly dressed. The big change In my life was when I went into the Army,'' he says. "I didn't fight it I liked it."