392 



INTRODUCTION TO CRYPTOGAMIC BOTANY. 



evergreens in this country, connects the genus closely with 

 Aster ilia. The other so-called European species are very 

 obscure. An anamorphosis of many species frequently occurs, 

 in which vertical threads tipped with large conidia are deve- 

 loped, a state which constitutes the genus Cephaleurus. 



Fig. 81. 



a. CeiDlialeuroid state of Strigula Feei. From Ceylon. Sent by 

 Mr. Thwaites. 



b. Asci and sporidia of Ahrothallus Welwitschii. Communicated by 

 Dr. Montagne. From Portugal. 



e. Stylospores of A. SmitMi. Communicated by Dr. Lindsay. 

 d. Sporidia and asci of a Trypetheliuni. Gathered on the coast of 

 Guinea by M. Jardin. 



2. Trypetheliei, Fr. 



Crust sprinkled with pustules ; pustules consisting of a 

 heterogeneous, often coloured, stroma, circumscribed by a cor- 

 tical excipulum, and containing imbedded in its substance one 

 or more ostiolate perithecia. 



431. These species are to Verrucaria, what Hypoxylon is to 

 Sphceria. There is in the more typical Verrucarice, a distinct 

 crust, as in Trypetheliiiifn ; but in the one case the perithecia are 

 scattered, or at the most crowded into little groups ; whereas in 

 Trypetheliuni they are immersed in a common cellular mass, 

 like the stroma of Hypoxylon. This mass arises from the 

 medullary substance with which it often agrees in colour, 



