KEY TO THE ARRANGEMENT. 3 



Spores ellipsoid, bilocular, more rarely quadri-pluri- 

 locular, brown. Thallus foliaceous, or now everniae- 

 form; cartilagineous. 



12. PYXINE. Apothecia from scutellaeform becoming 



black all over, and lecideoid. Spores oblong-ellipsoid, 

 bilocular (elsewhere also 4-locular) brown. Thallus 

 crustaceous-foliaceous, sub-cartilagineous. 



Fam. 3. UMBILICARIEL Thallus horizontal, foliaceous, 

 coriaceous-cartilagineous, sub-monophyllous, attached to 

 the substrate at a single point. 



13. UMBILICARIA. Apothecia sub-scutellaeform, black- 



ened, gyrose-plicate. Spores sub-ellipsoid, simple, or 

 now muriform-multilocular, brown, or decolorate. 

 Thallus as above. 



Fam. 4. PELTIGEREI. Thallus piano-ascendant, frondose- 

 foliaceous ; beneath villous, and variegated with veins, 

 or cyphels. [See Sticta.] Gonirnia take very largely the 

 place of gonidia. 



4. STICTA. Apothecia scutellsBform, sub-marginal, ele- 

 vated. Spores from fusiform at length acicular, bi- 

 quadri-plurilocular, fuscescent or colourless. Thallus 

 frondose - foliaceous, coriaceous - cartilagineous, the 

 under side variegated with little cups or rounded 

 heaps of unknown import (cyphels} or spots. Goni- 

 mous layer constituted, in one group of species, of 

 gonidia ; in the other of gonimia. 



15. NEPHROMA. Apothecia reniform, innate in the under 

 side of extended lobes, the margin disappearing. 

 Spores sub-fusiform, 4-locular; fuscescent. Thallus 

 frondose, not veined below. Gonimous layer, in one 

 group of species, of gonidia ; in the other of gonimia. 

 / 16. PELTIGERA. Apothecia pel tseform, adnate to the upper 



