Lithophyllum gardineri Foslie, 1907a: 30–31 ("forma typica'') (lectotype locality: Coetivy Reef, Seychelles fide Adey & Lebednik, 1967: 48).—Foslie, 1907c: 106–107, pl. 15: figs. 1–4 ("forma typica'').— Foslie, 1907d: 190–191, pl. 19: figs. 1–4 ("forma typica'').— Gardiner, 1907: fig. 30 (lower).— Foslie, 1909: 44–45 ("forma typica'').— Foslie, 1929: 34, pl. LXX: figs. 1, 8 ("forma typica'').— Adey & Lebednik, 1967: 48.— Woelkerling, 1993: 102–103.
Porolithon gardineri (Foslie) Foslie, 1909: 57.—De Toni, 1924: 691.— Hackett, 1977: 21 ("forma typica'').— Kalugina-Gutnik, Perestenko, & Titlyanova, 1992: 17 (table 1).
Hydrolithon gardineri (Foslie) Verheij & Prud'homme van Reine, 1993: 451.—Verheij, 1994: 106–107, figs. 27, 29.
Taxonomic synonyms:
* Lithophyllum coarctatum Foslie, 1907a: 31–32 (type locality: Cocos [Keeling] Islands).—Foslie, 1929: 32, pl. LXX: fig. 2 ("forma typica'').— Adey & Lebednik, 1967: 48.— Woelkerling, 1993: 52–53.
Porolithon coarctatum (Foslie) Foslie, 1909: 57.—De Toni, 1924: 692.
Lithophyllum gardineri Foslie forma obpyramidatum Foslie, 1907a: 30–31 (`obpyramidata') (lectotype locality: Coetivy Reef, Seychelles fide Woelkerling, 1993: 160.).—Foslie, 1907c: 106–107, pl. 15: figs. 5–8.— Foslie, 1907d: 190–191, pl. 19: figs. 5–8.— Foslie, 1929: 34, pl. LXX: figs. 9–12.
INDIAN OCEAN DISTRIBUTION: Aldabra Islands, Chagos Archipelago, Cocos [Keeling] Islands, Maldives, Seychelles (including Coetivy Reef).
Note: This species was also recorded from the Seychelles by Titlyanova, Perestenko, & Kalugina-Gutnik (1992: 43) as Spongites gardineri, but this intended combination is invalid since the authors did not cite the basionym and thus failed to satisfy Art. 33.2. The conspecificity of Lithophyllum gardineri, L. gardineri forma obpyramidatum, and Lithophyllum coarctatum was proposed by Verheij (1994: 106). Lithophyllum gardineri forma obpyramidatum was considered conspecific with Porolithon marshallense W.R. Taylor (1950: 128–129, 209, pl. 67, pl. 76: fig. 1; type locality: Kabelle Island, Rongelap Atoll, Marshall Islands), a species not reported from the Indian Ocean, by Taylor (l.c.).