Collemopsidium foveolatum forme saxicole.
This form is characterized by its occurrence at the base of soft limestone cliffs in the Patella and Balanus area. It is particularly well developed with a relatively thick grayish-white thallus, raised on the substrate, bordered by a "scar" thickening, black perithecia buried in a well bordered by a "volcanic" elevation and pycnidia more small, black without embossed edges. Frequently with Collemopsidium sublitorale forme saxicole.
N.B. Form much better developed than Collemopsidium foveolatum forme sur Ostrea which it resembles.