Phyllactidium confervicola Kützing, 1843b: 295 (type locality: Trieste, Italy).
Melobesia confervicola (Kützing) Foslie, 1900b: 6.—Islam, 1974b: 87 (with query).— Islam, 1976: 54 (with query).— Islam & Aziz, 1987: 212–213, pl. I: fig. 7; pl. III: figs. 18, 19.
Pneophyllum confervicola (Kützing) Chamberlain, 1983: 385–387, 389–392, figs. 43, 45, 46 (`confervicolum') (including Indian Ocean record).—Kalugina-Gutnik, Perestenko, & Titlyanova, 1992: 17 (table 1).— Titlyanova, Perestenko, & Kalugina-Gutnik, 1992: 43.
Taxonomic synonyms:
Hapalidium callithamnioides P. Crouan & H. Crouan, 1859a: 287, pl. 21: fig. D (lectotype locality: Rade de Brest, Finistère, France fide Chamberlain, 1983: 395).
Melobesia callithamnioides (P. Crouan & H. Crouan) Falkenberg, 1879: 265.—Weber-van Bosse, 1913b: 141.— Weber-van Bosse, 1914: 305.
Melobesia minutula Foslie, 1904b: 8–9 (type locality: Hvaler Islands, Oslofjord, Norway).—Untawale, Dhargalkar, & Agadi, 1983: [30].
Fosliella minutula (Foslie) E. Ganesan, 1964: 38–43, figs. 1–9 (including Indian Ocean records).—Umamaheswara Rao & Sreeramulu, 1970a: 37–38, figs. 35, 36.— Untawale, Dhargalkar, & Agadi, 1983: [30].
INDIAN OCEAN DISTRIBUTION: Bangladesh, Chagos Archipelago (Egmont Atoll)?, India, Seychelles.
Note: The synonymy follows Chamberlain (1994b: 137–138). The unconsolidated form of this species was given infraspecific status as forma minutulum (Foslie) Chamberlain (1983: 392), but this taxonomic recognition was later deemed unnecessary (Chamberlain, 1994b: 140). The confusion surrounding the epithet callithamnioides was discussed by Chamberlain (1983: 352). When Falkenberg made the combination Melobesia callithamnioides, he misapplied the name to an alga from the Gulf of Naples. Solms-Laubach (1881: 11, pl. I: figs. 9, 12, 13) noted the misapplication and referred to Falkenberg's alga as "Melobesia callithamnioides Falkenbg non Crouan''. By providing illustrations, he satisfied the requirement for valid publication in accordance with Art. 44. The name, however, is a later homonym of M. callithamnioides (P. Crouan & H. Crouan) Falkenberg. Noting the homonymy, Falkenberg (1901: 109, footnote) proposed a new name, M. solmsii, for the Neapolitan alga. Foslie (1905b: 96–102), however, thought that it was merely a filamentous form of M. farinosa Lamouroux (Hydrolithon farinosum (Lamouroux) Penrose & Chamberlain (q.v.)), to which he gave the name forma callithamnioides (Falkenberg) Foslie. Because M. callithamnioides Falkenberg, the intended basionym, is illegitimate and hence not priorable, M. farinosa forma callithamnioides must be attributed directly to Foslie. Chamberlain (1983: 351) continued to recognize Foslie's forma under Fosliella farinosa (Lamouroux) Howe, but later (Chamberlain, 1994b: 117) questioned the taxonomic placement of Solm-Laubach's alga and stated that what she had been calling forma callithamnioides was a growth form of Hydrolithon boreale (Foslie) Chamberlain [p. 235]. Weber-van Bosse (l.c.) recorded "Melobesia callithamnioides, Falk.'' from the Chagos Archipelago and included Brest in the distribution, but with a query, so that it uncertain to which species this record should be referred. V. Krishnamurthy & H. Joshi (1970: 19) erroneously credited M. Balakrishnan (1947) with recording Melobesia minutula from India.