RAMEAU'S NIECE by Cathleen Schine (Ticknor & Fields/Houghton Mifflin). A smart, funny send-up of academia that parodies the postmodern form it imitates. Heroine Margaret Nathan, 28, a chronologically forgetful historian, is nevertheless one of fortune's darlings. Her dissertation, a biography of an obscure 18th-Century woman who had written a strange book on anatomy that renamed body parts, is hailed as a "seminal work in the study of the politics of the body" by feminists and deconstructionists, none of whom has actually read it. Along with much else that is wonderful about this book, it is Schine's subtly hilarious dialogue that is the heart of its charm, whether depicting 40-year-olds who still boast about their SAT scores or culturally elitist strangers at a dinner party feigning interest in one another.