120 FUNGUS-FLOEA. 



little scattered pits or depressions; spores elliptic-oblong, 



7 X 4: fl. 



Corticium porosum. Berk, and Curt., Ann. Nat. Hist., ser. 5, 

 iii. (1870), p. 211 ; Mass., Mon. Thel., p. 121. 



On wood. Colour of -wash leather; hyraenium often 

 sterile, and then spongy and porous. When dry often 

 cracked into large pieces, gaping, the edges curling up. 



The pores look as if little dewdrops had settled on the 

 hyraenium, which had in consequence contracted, or rather 

 retracted. (B. & C.) 



Corticium populinum. Fr. 



Usually commencing as minute silky patches that become 

 confluent and effused, and with the margin involute; hy- 

 menium uneven, greyish ferruginous ; white and downy 

 below ; spores subglobose, 7-8 /x diameter. 



Gorticium 2iopulmiim, Fries, Epicr. 559 ; Mass., Mon. Thel., 

 p. 121. 



On poplar. Often springing from old Sphaeriae; distin- 

 guished amongst its allies by the ferruginous hymenium and 

 subglobose spores. 



Corticiuin lycii. Cooke. 



Commencing as small round patches that run into each 

 other and form an irregular, effused thin patch, margin 

 usually free, but not always, hymenium bright lilac, when 

 old often with a tinge of ochre, not cracked when dry ; spores 

 elliptical, 8 x 4 /a. 



Corticium. lycii, Cooke, in Mass., Mon. The]., p. 122. 



Thelejphora lycii, Pers. 



On Lycium and Syringa. Care must be taken not to 

 confound the present species with young resupinate speci- 

 mens of Stcreum puijiureum. 



**• 



Margin not free, indeterminate, hyssoid or strigose. 



I llymenium whitish or ochraccous. 



Corticium calceum. Fr. 

 Thin, Ijroudly cft'u.scd, margin usually determinate, but 

 closely adglutinated, hymenium smooth, polished, whitish, 



