Plate 9 from Rex Filson's The Lichens and Mosses of Mac.Roberston Land.
Microscopic views of various features of Buellia grimmiae. Figure (a) shows a cross section of part of a specimen and (b) shows an enlargment. In both you can make out a number of spore-bearing asci. Asci are shown larger and in various stages of development in (c), while (d) shows some mature spores and (e) a branched paraphysis.