INTRODUCTION TO CRYPTOGAMIC BOTANY. 401 



the medullary stratum, and must, in fact, be considered as part 

 of the excipulum. The sporidia often adhere together hke little 

 necklaces, but they are at first contained in distinct asci. They 

 are either simple or uniseptate, orbicular or sub-elliptic. Far 

 .the greater part of the species grow on wood ; but one or two 

 inhabit rocks. Oalicium turbinatum occurs on the crust of 

 Pertusaria, and has been supposed by Wahlenberg to be a 

 degeneration of its ostiola. This notion, however ingenious, is 

 contradicted by the presence of proper fruit, totally different 

 from that of the matrix. The production ought probably to 

 be separated, under the name of Bfhinctrina, and has almost 

 as much right to be placed amongst fungi as lichens. One 

 species, closely allied, is found on the masses of gum which 

 flow from Cerasus serotinus in South Carolina. Trachylia 

 has scabrous, homy, immarginate excipula, resembling in form 

 those of some Leoidea, but differing in the pulverulent fruit, 

 while Ooniocyhe, which approaches closely to Fungi, has a 

 proper excipulum, destitute of any distinct margin, and splitting 

 above. In Ccdicium inquvnana the sporidia are so loosely 

 attached that they make a sooty impression upon the fingers 

 when they are touched. Tulasne figures curved spermatia in 

 C. turbinatum. The species are almost wholly confined io 

 Europe and North America, especially the cooler parts. One 

 species has been found in New Zealand. 



2. Glyphidei, Fr. 



Disc coloured, at first nesthng in the medullary substance of 

 the crustaceous thallus, then exposed and surrounded by the 

 thallus, which is swollen into pustules. Excipulum mostly 

 absent or spurious. 



438. This tribe is exactly analogous to Try2Jetheliei. The 

 thallus is raised here and there into pustules, or distinct ex- 

 pansions, in which the open discs are set like the stones of a 

 mosaic. The expanded surface is often coloured and irregular, 

 and the species have sometimes a fungoid aspect. There is, in 

 point of fact, no true border to the disc, the perithecium being 

 reduced to a thick conical base, from which proceed imme- 

 diately the asci and paraphyses ; each individual hymenium 

 being surrounded by the intervening medullary matter, injected 

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