Admirers of the great novelist Vladimir Nabokov (1899-1977) know that collecting and classifying butterflies was for him not so much a hobby as an obsession, especially during the 1940s, when he worked for Harvard's Museum of Comparative Zoology and made important discoveries about the American genera known as Blues. Butterfly-linked images and ideas pervade some of his fiction, and butterfly-collecting expeditions took up much of his free time. Nabokov biographer Boyd and butterfly expert Pyle team up to offer a gigantic compendium of butterfly-relevant Nabokoviana. Reprinted here are draft reminiscences later revised for the autobiography Speak, Memory; the 1920 technical paper ""A Few Notes on Crimean Lepidoptera""; selected parts of the later scientific and technical work; numerous poems with butterfly-related lines, some in English, some translated from Russian; Nabokov's last short story, ""The Admirable Anglewing""; excerpts from letters and interviews; notes for the New Yorker (""Incidentally, pinching the thorax is a much simpler way of dispatching a butterfly"") and segments of Nabokov's lecture notes; and lepidopteran passages from the novels and stories. Among the previously unpublished works, one standout is the 36-page essay (originally in Russian) that Nabokov meant to use as the afterword to The Gift. Also present are the surviving fragments of Nabokov's never-completed descriptive catalogue, Butterflies of Europe. Boyd and Pyle contribute separate, informative and sometimes parallel introductions. Not even a Nabokov-obsessed taxonomist would want to read this collection from start to finish: it is, though, a volume devotees will delight to browse in and scholars will want to own. 30 color and 30 b&w illus. Agent, Georges Borchardt. (Apr.) FYI: For more information on Nabokov's Butterflies, see Book News, Feb. 28.