Synoynms: Phyllactidium confervicolum ['confervicola'] Kützing (1843) p. 295; Hapalidium phyllactidiumKützing (1849) p. 695; Hapalidium confervicolum (Kützing) Areschoug da J. AG. (1852) p. 509; Hapalidium callithamnioides P. & H. Crouan (1859) p. 289; Hapalidium confervoides (Kützing) P. & H. Crouan pro parte (?) (1867) p. 149; Melobesia confervicola (Kützing) Foslie (1900) p. 21; Melobesia minutula f. typica Foslie (1909) p. 56; Melobesia fosliei Rosenvige (1917) p. 249; Heteroderma minutula Dawson (1956) p. 47; Fosliella minutula (Foslie) Ganesan (1963) p. 38; Melobesia minutula f. lacunosa Foslie (1905) p. 107 (nom. illeg. ICBN Art. 63.1); Pneophyllum confervicolum f. minutulum (Foslie) Chamberlain (1983) p. 392.

VEGETATIVE FEATURES

Thallus habit: encrusting, adherent, flattened; partially unconsolidated, more or less circular or lobed. Entire, thin, margin without orbital ridges; smooth surface. Size: diameter up to 2mm; thickness up to 0.01mm. Colour of living specimen: from pale pink, rather transparent to bright pink. Colour of dried specimen: white, yellow ivory.

Thallus entirely bistratose. Basal filaments: unilayered, squarish cells (A-B): 5-14µm long x 4-16µm in diameter. Epithallial cells: often lenticular (A-B). Cell connections: cell fusions. Other features: common intercalary trichocytes, dimensions similar to other thallus cells.

Gametangial conceptacles: spermatangial near the carpogonial, flask-shaped chambers, 30µm diameter x 23µm high, spout present; carpogonial conceptacles with domed chambers. Tetra/bisporangial conceptacles: uniporate, hemispherical, raised bubble-shaped (C), from spread to crowded. Conceptacles surface stepped; chambers domed to elliptical: 52-91µm diameter x 30-74µm high. Small columella sometimes present. Canal pore simple (occasionally with hyaline extrusions). Phenology: ---

Habitat: rather common. Epiphytic on a wide range of algal species, particularly on Cladophora, Palmaria and Phyllora species but also on articulated corallines, Zostera, hydroids and bryozoans. Bathymetric distribution: littoral to lower sublittoral. Geographic distribution (Babbini & Bressan 1997):

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