Polysiphonia subtilissima Montagne, 1840: 199 (type locality: Cayenne, French Guiana).—Biswas, 1932: 193–194, pl. 31: figs. 32–37.— Parija & Parija, 1947: 378.— Børgesen, 1954a: 36–37, fig. 14.— Patnaik, 1973: 62.— Radhakrishnan, 1976: 112.— Patnaik, 1979: 64.— Allender, 1981: 19, 20, 22.— Lambert, Steinke, & Naidoo, 1987: 358, figs. 4C,D.— Coppejans & Gallin, 1989: 52.— Steinke & Naidoo, 1990: 229 (table 1).— Kalugina-Gutnik, Perestenko, & Titlyanova, 1992: 21 (table 1).— Titlyanova, Perestenko, & Kalugina-Gutnik, 1992: 44.— A. Phillips et al., 1994: 571.
Taxonomic synonym:
Polysiphonia angustissima Kützing, 1864: 17, pl. 47: figs. d–g (type locality: Brighton, Port Phillip, Victoria, Australia).—G. Martens, 1871a: 172.— Prain, 1905: 331.— Biswas, 1926: 35, pl. X: fig. 26.— Biswas, 1949a: 104.
INDIAN OCEAN DISTRIBUTION: Aldabra Islands, Australia, India, Kenya, Mauritius, Seychelles, South Africa.
Note: The synonymy was proposed by Womersley (1979: 469).