The Mosquito Coast, by Paul Theroux (Avon, $3.95). The patriarch of an American family, convinced America has turned into a "dope-taking, door-locking, ulcerated danger zone of rabid scavengers and criminal millionaires and moral sneaks," takes his family-- Mother, twin daughters and two boys--to the steaming jungles of Central America, there to build the perfect paradise. But this exercise in Yankee individualism turns into a grim fight for survival when the father's zeal pushes everyone's endurance to the breaking point. Been Down So Long It Looks Like Up to Me by Richard Farina (Penguin, $4.95). Farina, who was killed in a motorcycle accident two days after this book was published in 1966, was a sort of link between the Beat '50s and the activist '60s. This comic novel is about a campus in revolt in the late '50s, before this became a regular part of college life. According to Thomas Pynchon, whose introduction adorns this edition, the campus is Cornell, where he and Farina were students and friends. The protagonist, Gnossos Pappadopoulis, wanders amid the nascent psychedelia, tasting each of the gods, false and otherwise, that came to dominate the '60s. NONFICTION The Rise of Political Consultants: New Ways of Winning Elections, by Larry J. Sabato (Basic Books/Harper Colophon, $9.95). H.G. Wells said an election is "democracy's ceremonial." The thesis of this important study is that political consultants have become as important as voters and candidates in determining the outcome of elections. Chapter titles include: "The Consultant Corps"; "The Pols and the Polls"; "The Media Masters"; "Direct Mail--The Poisoned Pen of Politics"; "Parties, PACs, and Political Consultants." David Broder of The Washington Post said this book "will be a standard reference for those who want to understand this controversial phenomenon." Thorn Bird Country, by Catherine Marshall, with an introduction by Colleen McCullough and photographs by Jo Daniell (Warner, $12.95). You don't necessarily have to have been a reader of McCullough's best- selling novel, The Thorn Birds, to appreciate this hymn to the Australian Outback. The Epidemic That Never Was: Policy-Making and the Swine Flu Scare, by Richard E. Neustadt and Harvey V. Fineberg (Vintage, $7.95). In 1976 the U.S. government tried to immunize every citizen against a new form of influenza called swine flu. More than 40 million persons in 10 weeks were immunized, but then began delays, legal complications, unforeseen medical sid effects, and a loss of credibility for public health authorities when the swine flu epidemic never materialized. Here two Harvard scholars dissect the decision-making process to determine what went wrong. Fabulous Chicago, by Emmett Dedmon (Atheneum, $9.95). "I saw a man who danced with his wife, in Chicago," runs the popular song. This lively history of the second city, which rose from Indian trail to "hog butcher to the world," helps explains why Chicago is such a toddlin' town.