6 THE LICHEN-FLORA 



Tribe X. Cetrariei. 



Thallus spadiceous, laoiniose or fistulose. = Cetraria. 

 Thallus vai-ious in colour, membranaceo-dilatate and lobate. = 

 Platysma. 



Series IV. PHYLLODEI. 



Tribe XL Peltigerei. 



Sub-tribe I. Nephromei. 



Cortical layer continuous on the nerveless lower surface of the 

 thallus ; spores septate. = Nephromium. 



Sub-tribe II. Peltidei. 



Cortical layer not continuous on the nerved and rhizinose lower 

 surface of the thallus ; spores 3-5-7-septate. = Peltigera. 



Sub-tribe III. Solorinei. 



Cortical layer not continuous on the obsoletely-nerved lower 

 surface of the thallus; spores 1 -septate. =Solorina. 



Tribe XII. Parmeliei. 

 Sub-tribe I. Stictei. 



Gonidial stratum of the thallus consisting of glauco-virescent or 

 glauco-cserulescent granula gonima in pluri-locular nodules. = 

 Stictina. 



Gonidial stratum of the thallus consisting of free, true, bright 

 or yellow-green gonidia ; rhizinse simple. = Sticta. 



Under surface of thallus with fasciculate rhizinre ; spores 1-3- 

 septate. = Ricasolia. 



Sub-tribe II. Imbricariei. 

 Spores simple. = Parmhlia. 



Sib-ibibe III. Physciei. 

 Spores polari-bilocular or 1-septate. = Physcia. 



Tribe XIII. Gyrophorei. 

 Thallus monophyllous, umbilically affixed. = Umbilicaria. 



Series V. PLACODE! 



Tribe XIV. Lecanorei. 



Sub-tribe I. Psoromei. 



Gonidial stratum of thallus consisting of large distinct gonidia - 

 = Psoroma. 



