308 



POPULAR HISTORY OF LICHENS. 



1. Pykenothea letjcocephala (kev/cos, wMte, and /ee- 

 fyakrj, the head). Thallus glaucous or whitish, leprose, 

 warted with tubercles of the same colour or whiter ; exciple 

 whitish-pulverulent ; thalamiuin covered with a pale brick- 

 coloured dust, at length naked. Spores innumerable, irregu- 

 lar, gibbous, linear-oblong, pale yellow. (E. B. 2642.) 



On fir and other trees in lowland woods. Its spermo- 

 gones are prominent, black, obtuse, at first whitish-pulve- 

 rulent ; the spermatia are numerous, straight, and linear. 

 The fructification is rare. 



Genus II. STRIGULA, Fries. 



Gen. Char. Thallus generally developed below the epidermis 

 of coriaceous perennial leaves, on which the plant is parasitic. 

 Perithecia subglobose, collapsing, opening at length by a pore 

 or fissure. Thalamium gelatinous, becoming rigid, black, and 

 cracking on exposure. 



1. Strigula Babingtonii. A species growing on the 

 leaves of the Box and Laurel in various parts of England, — 

 having subcymbiform, three-septate spores. Named after 



c Hooker's Journ. of Bot. and Kew Garden Miscellany/ vol. iii., 1851 : Tu- 

 lasne, c Comptes rendus de l'Acad. des Sc./ March 31, 1851. 



