Habitat: Common on reef environments, coral rubble, seagrass beds. Distribution: Colombia, Brasil, Puerto Rico, Virgin Islands, Bocas del Toro (Panamá). Characteristics: Shape: lobate, lobes can be irregularly shaped. Lobes typically 3-5cm tall. Spreading mass of lobes on coral rubble substrate. Color: external brown/maroon, internal light tan Consistency: Very firm, crumbles when crushed. Surface: rugose surface, texture like fine sandpaper Apertures: oscules 2-5mm in diameter, located at tips of lobes. 1 oscule per lobe. Skeleton: spicules consisting of strongyles only. isotrophic to confused spicule tracts. Others: no odor or exudate Notes: This species is associates with symbiotic cyanobacteria. Larvae are positively phototrophic. Synonyms: Densa araminta de Laubenfels, 1934 Thalysias proxima Duchassaing & Michelotti, 1864