London, John Murray, 1929. First Edition. First Impression. Hardback. An excellent copy, without the jacket. Contains four novellas including the final two Challenger stories. Condition. Overall a bright and sharp copy, some rubbing to the gilt to the publisher's imprint on the spine. Pushing to upper spine tip. 10pp ads to rear [Locke, I:71; Bleiler, p63 as collection, supernatural, science fiction and lost continents] [8043, Hyraxia Books].