Lithophyllum gardineri Foslie forma subhemisphaericum Foslie, 1907a: 30 (`subhemisphaerica') (syntype localities: Chagos Archipelago; Coetivy Reef, Seychelles).—Foslie, 1907c: 106–107, pl. 16.— Foslie, 1907d: 190–191, pl. 20.— Foslie, 1929: 34, pl. LXXI: fig. 1.— Adey & Lebednik, 1967: 47 (without designation of forma).— Woelkerling, 1993: 210.
Porolithon gardineri (Foslie) Foslie forma subhemisphaericum (Foslie) W.R. Taylor, 1950: 129 (`subhemisphaerica').
INDIAN OCEAN DISTRIBUTION: Chagos Archipelago, Seychelles (Coetivy Reef).
Note: According to Woelkerling (l.c.), the status of this form is uncertain since a type specimen could not be located.