CLASSIFICATION 413 



sometimes minutely byssoid. Superficially resembling Corticiiim 

 ladescens, but readily distinguished by the coloured spores. 

 On decorticated wood. 



CORTICIU.AI 



Forming closely adherent thin crusts on wood and bark ; hy- 

 menium smooth and polished, becoming cracked when dry. Spores 

 colourless. 



Closely resembling species of PeniopJiora in habit ai^i colour, but 

 distinguished by the absence of minute bristles or cystidia pro- 

 jecting from the hymenium, which is consequently perfectly smooth 

 or glabrous. 



I. Margin well defined, free, and often more or less upturned. 



C. salicinum. — -Patches about i in. across, hymenium blood-red, 

 margin raised, whitish and downy below. 



On wood and bark of poplar, willow, etc. 



C. evolvens. — Patches marginate, often effuso-reflexed, soft, 

 whitish, and tomentose below ; hymenium somewhat wrinkled, 

 pale brown, then ochraceous or whitish, cracked when dry. 



Often commencing as isolated round patches which sometimes 

 become saucer-shaped and remain solitary ; more frequently 

 several grow into each other and form irregular patches with the 

 margin more or less upraised, and fibrillose below ; hymenium 

 dingy ochraceous, sometimes with a lilac tinge, cracked when dry, 

 and showing the fibrillose under layer or subiculum. 



On bark, especially of rosaceous trees. 



C. porosum. — Often effused for several inches, margin sometimes 

 determinate and shghtly raised, at other times almost indeterminate ; 

 hymenium, when well developed, waxy, even, pallid, with little 

 scattered pits or depressions. 



Colour of wash-leather ; hymenium often sterile, and then 

 spongy and porous. When dry often cracked into large pieces, 

 gaping, the edges curling up. The pores suggest dewdrops having 

 settled on the hymenium, which had, in consequence, retracted at 

 those spots. 



On wood and bark. 



C. populinum. — Usually commencing as minute, silky patches 

 that run into each other, and spread, margin incurved ; hymenium 

 uneven, greyish ferruginous, white and downy underneath. 



Often springing from old Sphaeria; ; distinguished amongst its 

 allies by the ferruginous hymenium. 



On poplar. 



C. lycii. — Forming irregular patches of varial)le size ; hymenium 

 bright lilac. 



Superficially resembling Stcreum purpiircinii, which differs in the 

 velvety, sterile surface. 



On branches of Lycium and Syritiga. 



