Ulva umbilicalis Linnaeus, 1753: 1163 (type locality: "in Oceano'').
Porphyra umbilicalis (Linnaeus) Kützing, 1843b: 383.—Lucas & Perrin, 1947: 125, 127, figs. 5, 6.— Hodgkin, Marsh, & G.G. Smith, 1959: 87.— S. Dixit, 1970: 115.— Black, Lymbery, & Hill, 1988: 30.
INDIAN OCEAN DISTRIBUTION: Australia, Sri Lanka.
Note: Records of Porphyra umbilicalis from Australia probably are referable to P. lucasii Levring, and those from Sri Lanka to P. suborbiculata Kjellman.