Description

 Growth form irregular, massive; usually less than 10 cm in diameter, sometimes up to 15–20 cm in diameter and 2–3 cm in height. Colour in vivo (generally also preserved specimens) light grey to white; several, slightly perceptible, tone dominances are possible (light green to light brown). Consistency soft and fragile. Surface, shared by all species of the genus, as an irregular network of dense collagen fibres, sometimes with mineral debris. Inhalant apertures 80–120 µm in diameter. Oscules scattered (2–4 mm in diameter). Light collagen amount (fibrous reticulate) in the mesohyl. Flagellate chambers large. Skeleton reticulate, with irregular meshes (300–600 µm), and extremely fragile because of scanty spongin and extreme abundance of mineral granulation. Primary and secondary fibres (40–200 µm) not distinguishable or hierarchically organized.