in Mohr & al., Mycol. Res., 108: 529, 2004. Basionym: Arthopyrenia foveolata A.L. Sm. - J. Bot., London, 49: 43, 1911.
Synonyms: Arthopyrenia gyalectoides M. Knowles ex A.L. Sm.; Pyrenocollema foveolatum (A.L. Sm.) C. Mohr
Distribution: N- VG. S - Pugl (Nimis & Tretiach 1999 as C. halodytes),
Description: Thallus crustose, endosubstratic and hardly distinguishable from the substrate, forming 0.5-1 cm wide, grey-beige patches often separated by a thin raised rim. Perithecia scattered, black, 0.1-0.25 mm in diam., totally immersed in pits of the substrate, hardly visible to the naked eye as minute black dots. Involucrellum usually present, lid-like, flat to slightly convex, hardly spreading laterally; exciple dark, more or less cellular; hamathecium of branched and anastomosing pseudoparaphyses, the hymenial gel I-. Asci 8-spored, ovoid to subcylindrical, usually stalked, with two functional wall layers, K/I-, the wall thickened above, with an ocular chamber, fissitunicate, with a distinct extruded rostrum at dehiscence. Ascospores 1-septate, hyaline, oblong, one cell usually longer than the other, 14-21 x 5-9 µm. Photobiont cyanobacterial, the cells in scattered groups, sometimes absent. Spot tests: all negative. Chemistry: without lichen substances.
Note: probably this is the most common species of the genus along the Italian coasts, where it most often occurs on barnacles; in the past, it has been frequently confused with C. halodytes (e.g. all records of that species from the Trieste coast refer to C. foveolatum).