(Cirripedia: Balanomorpha) in Taiwan: a Reappraisal

obligatory symbionts found on actively growing surfaces of milleporine corals. These morphologically distinct species are geographically isolated from one another, with the former occurring in the tropical western Atlantic and the latter in the western Pacific. Contrary to current thought, M. stultus occurs only in the western Atlantic, the type locality for which is herein designated as St. Vincent I. The type host for M. stultus is likely Millepora complanata Lamarck, 1816 whereas that for M. ajax is Mil. platyphylla Hemprich and Ehrenberg, 1834. Key words: Megabalanus ajax (Darwin), Type locality, Type host, Morphology. Darwin (1854) was the first to describe the obligatory symbiotic barnacles Balanus stultus and Balanus ajax, both of which occur on the fire coral, Millepora Linnaeus, 1758. Although Darwin vacil-lated when it came to placing B. stultus in a specific group, Ross (1968: 14) referred it to the subgenus Megabalanus Hoek, 1913, which was later accorded generic rank (Newman and Ross 1976: 39). Ther