A new species of Madreporaria, Polycyathus fulvus, is described from New Caledonia. Zooxanthellae have been found symbiotic in its polyps, although the genus is ahermatypic. Another Polycyathus, P. senegalensis Chevalier, 1966, is recorded from the Caribbean area; it was previously known from the eastern tropical Atlantic only. These two records extend the known range of the genus and show it to have a circumequatorial distribution in warm and warm-temperate waters.