“A ship landing on a whale mistaken for an island in an early thirteeth century bestiary (London, British Library, Harley MS 4751, f. 69r, c. 1230-1240).”
“In the Indian Ocean there are whales which are so large that they seem to be islands. And sometimes because of the soil they have on them plants grow on their backs. Men crossing the sea sometimes land on these whales, which, when they feel the movement of men on them, hurry down into the depths, and so the men are drowned.”
bad, bad fishes ! click the pic for lots more map monsters on BibliOdyssey. enjoy !