Rhodophyta (Red/Brown Algae)
Class: Bangiophyceae
Order: Bangiales
Family: Bangiaceae
–No subordinate taxa
Class: Florideophyceae
Order: Ceramiales
Family: Delesseriaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Phycodrina elegans | Setchell & Gardner (1937) | - | 1977 | Galápagos Islands, Ecuador | Missing | Access |
| Vanvoorstia bennettiana | (Harvey) Papenfuss (1956) | Bennett's seaweed | October 1886 | Port Jackson, New South Wales, Australia | Extinct | Access |
Order: Corallinales
Family: Hapalidiaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Lithothamnion superpositum | Foslie (1900) | - | (rediscovered) | Western Atlantic Ocean | Invalid (synonym) | Access |
Order: Gelidiales
Family: Gelidiellaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Gelidiella ramellosa | (Kützing) Feldmann & Hamel (1934) | - | (rediscovered) | near Two Rocks, Western Australia, Australia | Rediscovered | Access |
Order: Gigartinales
Family: Gigartinaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Gigartina australis | J.Agardh (1899) | Turkish towel algae | 1892 | Sydney Harbour, New South Wales, Australia | Extinct | Access |
Order: Gracilariales
Family: Gracilariaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Gracilaria skottsbergii | W.R.Taylor (1945) | - | 1934 | Galápagos Islands, Ecuador | Missing | Access |
Order: Nemaliales
Family: Galaxauraceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Galaxaura barbata | R.Chou in W.R.Taylor (1945) | - | 1963 | Floreana (Post Office Bay) & Santa Cruz (Tortuga Bay), Galápagos Islands, Ecuador | Missing | Access |
Class: Phaeophyceae
Order: Desmarestiales
Family: Desmarestiaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Desmarestia tropica | W.R.Taylor (1945) | Tropical acidweed | 1972 | Galápagos Islands, Ecuador | Missing | Access |
Order: Dictyotales
Family: Dictyotaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Dictyota galapagensis | (Farlow) De Clerck (2006) | - | 1974 | Galápagos Islands, Ecuador | Missing | Access |
| Spatoglossum schmittii | W.R.Taylor (1945) | - | 1978 | Galápagos Islands, Ecuador | Missing | Access |
Order: Fucales
Family: Fucaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Gongolaria montagnei | (J.Agardh) Kuntze (1891) | - | (rediscovered) | Algeria | Rediscovered | Access |
Family: Sargassaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Bifurcaria galapagensis | (Piccone & Grunow) Womersley (1964) | Galápagos stringweed | February 1983 | Galápagos Islands, Ecuador | Missing | Access |
Order: Sporochnales
Family: Sporochnaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Nereia lophocladia | J. Agardh (1897) | - | (rediscovered) | New South Wales & Victoria, Australia | Rediscovered (twice?) | Access |