On its cover, “Tales of the Marvellous and News of the Strange” is described as “the first English translation of a medieval Arab fantasy collection.” First discovered in 1933, in Istanbul, in a unique manuscript, it is now presented in English by the distinguished Arabist Malcolm C. Lyons, who a mere seven years ago brought out a complete and up-to-date translation of “The Arabian Nights: Tales of 1001 Nights.” For each of those three hefty volumes, Robert Irwin, best known for “The Arabian Nights: A Companion,” supplied a characteristically learned and engaging introduction, as he does again for this new book.