Synonyms: Millepora racemus Lamarck (1818) p. 203; Lithothamnium crassum Philippi (1837) p. 388; Lithothamnium racemus Areschoug (1851) da J. Agardh, Sp. Alg. p. 521; Spongites crassa Kützing (1858) p. 35; Pseudolithophyllum racemus (Lamarck) Mendoza & Cabioch (1984) p. 145.

VEGETATIVE FEATURES

Thallus habit: globoid with small, bulky protuberances on distal apex, often anastomosing (E). Rigid, not fragile cylindrical and very crowded protuberances. Lobed edge. Size: diameter up to 8cm, protuberances 2-6mm high, basal crust 0.5mm thick. Colour of living specimen: pink-grey, violet. Colour of dried specimen: pink grey, violet. 

Basal filaments: unilayered; squarish to rectangular cells: 8-12µm long x 4-9µm diameter. Erect filaments: multilayered (B); rectangular cells: (13) 18 (22)µm long x 6-10µm diameter. Epithallial cells: flattened, 5-10µm diameter (A). Cell connections: secondary pit-connections (A).

Conceptacles: slightly raised (C-D), grouped at distal apices of protuberances, in tiers (in longitudinal sections). Gametangial conceptacles: unknown; spermatangial conceptacles: 71-77µm in diameter x 13-22µm high. Tetra/bisporangial conceptacles: uniporate, 225-300µm in diameter x 70-180µm high, pore canal 60-80µm. Phenology: ---

Habitat: free-living on mobile substrata exposed to strong currents action, often in association with Phymatolithon calcareum, Lithothamnion corallioides, Spongites fruticulosa and with Lithophyllum stictaeforme. Bathymetric dsitribution: sublittoral to lower sublittoral. Recorded from (10) 20 to 65m deep. Geographic distribution (Babbini & Bressan 1997):

Western Mediterranean Sea (African shores) (B): Algeria; Middle Western Mediterranean Sea (C): France, Italy; North Western Mediterranean Sea (D): Spain, France; North Adriatic Sea (E): Italy, Slovenia, Croatia; Middle Adriatic Sea (F): Italy, Croatia; South Adriatic Sea (G): Italy, Albania; South Eastern Mediterranean Sea (H): Italy, Tunisia, Libya; Middle Eastern Mediterranean Sea (L): Greece; North Eastern Mediterranean Sea (M): Greece.