Lithothamnion engelhartii Foslie, 1900a: 18 (type locality: Cape Jaffa, South Australia).
Mesophyllum engelhartii (Foslie) Adey, 1970: 23.—Woelkerling & Harvey, 1993: 581, 584.— Barry & Woelkerling, 1995: 143.— Chamberlain & Keats, 1995: 134–144, figs. 1–7, 12, 36–51.
Taxonomic synonyms:
* Lithothamnion synanablastum Heydrich forma speciosum Foslie, 1900a: 11–12 (`speciosa') (type locality: "Grahamstown'' fide Foslie, 1929: 46 [probably near Port Alfred, Cape Province], South Africa).—Woelkerling, 1993: 204.
Lithothamnion speciosum (Foslie) Foslie, 1907b: 16–17.—De Toni, 1924: 627–628.— Foslie, 1929: 46, pl. VIII: figs. 2, 3.— Adey & Lebednik, 1967: 69.
Mesophyllum speciosum (Foslie) Adey, 1970: 26.
* Lithothamnion discrepans Foslie, 1907b: 8 (type locality: "Grahamstown'' fide Foslie, 1907b: 17 [probably near Port Alfred, Cape Province]).—De Toni, 1924: 626.— Foslie, 1929: 40, pl. V: fig. 3.— Adey & Lebednik, 1967: 83.— Woelkerling, 1993: 76.
Mesophyllum discrepans (Foslie) Lemoine, 1928: 252.—Adey, 1970: 23.— Branch et al., 1994: 340, pl. 162.10.
INDIAN OCEAN DISTRIBUTION: Australia, South Africa.
Note: The synonymy was proposed by Chamberlain & Keats (1995: 134).