252 



POPULAR HISTOBY OP LICHENS. 



On the beech in lowland forests in various parts of Eng- 

 land ; not very common. 



Genus IY. CHIOGRAPHA, Leight. 



Gen. Cha?\ Apothecium lirellate or subdisciform, sessile. Pe- 

 rithecium carbonaceous, surrounding the sides and base of a plane, 

 broad thalamium, which has a proper, and an accessory, thalline 

 margin. Thallus membranaceous. (Name from snow, and 

 ypacfrrj, writing, in allusion to the white, powdery, thalline margin.) 



1. Chiogbapha Lyellii. Thallus smooth, wavy, deter- 

 minate ; lirelke prominent, oblong or linear-oblong, simple, 

 curved ; proper margin narrow, prominent ; thalline margin 

 elevated, white, pulverulent. Thalamium plane, broad, prui- 

 nose. Spores linear, margined, rounded at ends, each con- 

 taining about seven or eight transversely oval, margined 

 cellules. (E. B. 1876.) 



On the oak in the New Forest, Hampshire, and other 

 parts of England. 



Genus V. AULACOGRAPHA, Leight. 



Gen. Char. Apothecium lirellate, subimmersed, prominent. 

 Perithecium carbonaceous, dimidiate, palmatifid, the base naked. 



