INTRODUCTION TO CRTPTOGAMIC BOTANY. 



891 



ture of any species, but the figure of Eschweiler seems to indi- 

 cate, from the linear arrangement of the sporidia, that there 

 are asci. The perithecia open exactly in the same way as 

 those of Phacidium, especially P. Delta, Kze. (Fig. 66, b), a 

 species which is very abundant in Madeira on the leaves of 

 laurels. The dehiscence in the other genera is much less 

 regular, and it is very probable that in CliostoTnum, in which 

 the corrugated appearance is due to the contraction of the 

 peridium, and dehiscence takes place eventually in the direc- 

 tion of these contractions, the spores are naked. Gyro- 

 stomum, Fr., is founded on Lecidea scyphulifera, Ach., a 

 species from Sierra Leone, which appears to be truly ascige- 

 rous ; but I have had no opportunity of examining any species. 

 Strigula Babingtonii, Berk., which is common on leaves of 



Fig. 80. 



a. Strigula nemaihora." 



b. Strigula FSei, with section of perithecium, asci, parapliyses, and 

 sporidia. From Ceylon. Communicated by Mr. Tliwaites. 



c. Cephalenroid condition of some Strigula. From Caripi. Com- 

 municated by Mr. Spruce. 



d. Paraphyses of a Lecidea allied to Z. sabuletorum, bearing stylo- 

 spores. From tte late Mr. Gardiner. 



All more or less magnified. 



* Mr. Babington considers Strigula as belonging to Verrucariei, but 

 the epiphyllous subepidermio origin and irregular rupture seem to 

 distinguish it. 



