Polycavernosa subtilis B. Xia & Abbott, 1987: 413–414, figs. 6, 14 (type locality: Middle Bank, Penang, Malaysia).
Hydropuntia subtilis (B. Xia & Abbott) Wynne, 1989a: 477.
Gracilaria subtilis (B. Xia & Abbott) B. Xia & Abbott in Abbott, Zhang, & B. Xia, 1991: 23.—Phang, 1994a: 129.
INDIAN OCEAN DISTRIBUTION: Malaysia.