London, John Murray, 1929. First Edition. First Impression. Hardback. A very good copy, without the jacket. Contains four novellas including the final two Challenger stories. Condition: Some dulling to the spine, a little foxing. 10pp ads to rear [Locke, I:71; Bleiler, p63 as collection, supernatural, science fiction and lost continents] [8069, Hyraxia Books].