Thallus: endolithic, inconspicuous, continuous, often bordered by a dark prothalline line surface: white to pale gray, dull or subnitid; anatomy: as for the genus (see above) Perithecia: fully immersed in the rock; broadly ellipsoidal to somewhat conical at the apex, colorless to dark brown, 10-20 µm thick, with a: 0.3-0.4 mm wide exciple involucrellum: lid-like, as broad as or smaller in diameter than the exciple, flat to slightly convex with downwards bent margin, 200-300 µm wide, 20-25 µm thick, often radially split by 3-5 cracks periphyses: 30-50 µm long, simple asci: clavate, 45-60 x 12-17 µm, 8-spored ascospores: hyaline, simple, oblong to ellipsoidal, 18-24 x 8-12 µm, often badly developed or lacking Pycnidia: unknown Secondary metabolites: none detected. Substrate and ecology: on calcareous rocks in open to partially shaded places from low to high altitudes World distribution: very common in limestone areas of Europe (mainly central and southern), with scattered occurrences in Asia, Tunisia, Australia, New Zealand, and North America Sonoran distribution: Arizona. Note: Probably Bagliettoa baldensis has a wider distribution in the Sonoran region, but determination of several samples was uncertain, because perithecia were badly developed and spores were lacking.