FAMILIES AND GENERA 329 



Thallus crustaceous non-corticate. 

 Spores simple. 

 Spores .small, thin-walled. 



Spores colourless i. Lecidea Ach. 



Spores brown 2. *Orphniospora Koerb. 



Spores large, thick-walled 3. Mycoblastus Norm. 



Spores I -septate. 



Spores small, thin-walled 4. Catillaria Th. Fr. 



Spores large, thick- walled 5. Megalospora Mey. and Flot. 



Spores elongate, 3-multi-septate. 



Spores elongate, narrow, thin-walled 6. Bacidia A. Zahlbr. 



Spores elongate, large and thick-walled 7. Bombyliospora De Not. 



Spores muriform. 



Spores colourless ; on trees 8. Lopadium Koerb. 



Spores colourless to brown ; on rocks 9. Rhizocarpon Th. Fr. 



Thallus warted or squamulose, corticate. 



Spores' elongate, 1-7-septate, thin- walled 10. Toninia Th. Fr. 



Thallus of upright podetia-like small fronds. 



Spores ellipsoid, becoming i-septate 11. *Sphaerophoropsis Wain. 



XXXII. P HYLLOPSORACEAE 



A small family of exotic lichens with a somewhat more developed thallus 

 than that of the Lecideaceae, being in both of the genera squamulose or 

 almost foliose. 



The apothecia are without a thalline margin ; they are biatorine or 

 lecideine ; the hypothecium is formed of plectenchyma and is purple-red 

 in one species, Phyllopsora fitrfuracea. The two genera differ only in spore 

 characters. There are • fifteen species, mostly corticolous, belonging to 

 Phyllopsora ; only one, from New Zealand, is recorded for Psorella. 



Spores simple i. *Phyllopsora Miill.-Arg. 



Spores elongate, septate 2. *Psorella Miill.-Arg. 



XXXIII. Cladoniaceae 



Associated with Lecideaceae in the type of apothecium, but differing 

 widely in thallus formation. The latter is of a twofold type : the primary 

 thallus is crustaceous, squamulose, or very rarely foliose ; the secondary 

 thallus or podetium, upright, simple or branched, is terminated by the 

 apothecia, or broadens upwards to cup-like scyphi. Algal cells, Protococ- 

 caceae, according to Chodat, Cystococcus. 



Much attention has been given to the origin and development of the 

 podetia in this family. They are superficial on granule or squamule 

 except in the monotypic Himalayan genus Gymnoderma where they are 

 marginal on the large leaf-like lobes. Though in origin the podetia are 

 doubtless fruit stalks, they have become in most cases vegetative in function. 



