318 



POPULAR HISTORY OF LICHENS. 



parasitic Celidium y it will be observed, are very distinct from 

 those of S. 'pulmonaria, which are lanceolate, acute at both 

 ends, and usually bilocular. C. Stictarum also constitutes 

 a deformed state of the apothecia of Sticta scrobiculata in 

 some parts of Scotland ; and it is the Lecanora parasitica of 

 some Continental authors. 



Genus IV. PHACOPSIS, Tul. 



Gen. Char. Apothecia innate-adnate, at first concealed by 

 thallus, afterwards naked or covered by a lacerated veil, black, 

 effuse, constituting deformed maculae or warts. Thecae obovate, 

 thick, six- to eight-spored. Spores oblong, few-septate, and pale. 

 Spermogones commonly immersed in centre of apothecia. Sper- 

 matia slender, straight, short. Pycnides unknown. Parasitic on 

 various foliaceous, fruticulose, and crustaceous lichens in West- 

 ern Europe. (Name from </xxkos, a ncevus, and oi/us, like, in allu- 

 sion to the black, fungiform maculae or warts.) 



1. Phacopsis varia. Spores oblong, obtuse at ends, 

 quadrilocular, and pale. Spermogones, when present gene- 

 rally immersed in centre of maculae, often absent. Sper- 

 matia straight and slender. — Tulasne mentions its occur- 

 rence on Parmelia parietina, both on its thallus and on the 

 margin and disc of the apothecia. 



