The following taxon apparently lies within the circumscription of Neogoniolithon spectabile but has not yet been transferred or reduced to synonymy:
Goniolithon spectabile Foslie forma? brevifultum Foslie, 1901a: 16, 18 (`brevifulta') (type locality: Mauritius).—Woelkerling, 1993: 44–45.
Misapplied name (fide Woelkerling, 1993: 45):
Goniolithon frutescens "forma typica''.—Foslie, 1929: pl. XLVIII: fig. 10.— Adey & Lebednik, 1967: 29 (Mauritius record; without designation of forma).
INDIAN OCEAN DISTRIBUTION: Mauritius.