Rhodochorton speluncarum Collins & Hervey, 1917: 147–148 (type locality: Bermuda).
Spermothamnion speluncarum (Collins & Hervey) Howe, 1920: 578.—Umamaheswara Rao & Sreeramulu, 1970a: 41, fig. 59.— S. Dixit, 1980: 75.— Untawale, Dhargalkar, & Agadi, 1983: [35].
INDIAN OCEAN DISTRIBUTION: India.
Note: E. Gordon (1972: 135) expressed the possibility that this species should be referred to Ptilothamnion.