Bryopsis tenuissima Moris & De Notaris, 1839: 259, pl. VI: fig. III (type locality: Cabrera, Islas Baleares).—G. Martens, 1869b: 456.— G. Martens, 1871b: 465.— Theobald, 1883: 28.— Biswas, 1949b: 31.— K. Srinivasan, 1961a: 229.— S. Dixit, 1970: 108.— V. Krishnamurthy & H. Joshi, 1970: 5.— Untawale, Dhargalkar, & Agadi, 1983: [11].
Derbesia tenuissima (Moris & De Notaris) P. Crouan & H. Crouan, 1867: 133.
INDIAN OCEAN DISTRIBUTION: Andaman Islands, Nicobar Islands.
Note: J. Feldmann (1950) showed that Derbesia tenuissima alternates with Halicystis parvula Schmitz ex G. Murray (1893: 50, pl. XIII: fig. 5; type locality: Golfo di Napoli, Italy).