But as soon as I saw what was inside, the book was in my cart. And I haven't read any of the stories, yet, because I can't stop looking at the striking illustrations! The book is Three and the Moon: Legendary Stories of Old Brittany, Normandy, and Provence by Jacques Dorey, illustrated by Boris Artzybasheff, and published in 1929.
Later in his career, Mr. Artzybasheff moved on to produce more detailed illustrations of three-dimensional, often surreal and grotesquely anthropomorphic objects. He also illustrated several Time, Life, and Fortune magazine covers.