Two species of the poecilostomatoid copepods, Allopodion ryukyuensis n. sp. and Xenomolgus varius Humes and Stock, are recorded from galls and crypts on the scleractinian corals Montipora informis and Porites sp.(p), respectively, in Okinawa, Japan. Allopodion ryukyuensis is distinguished from its sole congener, A. mirum Humes, by having shorter caudal rami and abdominal somites, rounded lateral margins of the female genital double-somite, and a greater number of setal elements on the third exopodal segment of legs 2-4. The morphological features of the galls and crypts on the scleractinian hosts inhabited by A. ryukyuensis and X. varius are described, and it is proposed that certain other scleractinian-associated copepods likely also make use of similar habitations.