CLASSIFICATION 399 



**** Spines white, oflen tinged yellow/ or grey when old. 



H. nodidosum. — Substance whitish, smooth, inseparable, forminj^' 

 very broad patches, nodulose ; spines long, depressed on the flat 

 portions, pendulous on the lower side of the nodules, upper side of 

 the nodules without spines. 



Often very broadly effused, nodules or lumps on the crust, vari- 

 able in size, sterile above, and bearing pendulous spines on the 

 under or lower surface. 



On trunks, fir stumps, etc. 



H. stevensoni. — Substance white, mealy beneath, here and there 

 byssoid ; spines cylindrical, blunt or truncate, sometimes com- 

 pressed, powdery at the tip, about i| lines long. 



Often forming patches 2-3 in. long, very thin ; spines rather 

 crowded, several often joined together at the base. 



On dead wood, encrusting leaves, moss, etc. 



H. niveiim. — Substance white, forming patches 2-3 in. across, 

 very thin, inseparable, edge byssoid ; spines crowded, short, equal, 

 smooth, white, minute. 



Distinguished by the clear white colour of every part when 

 growing, becoming pallid when dry. 



On dead wood, etc. 



H. farinaceum. — Substance white, spreading in patches which 

 end \'aguely, thin, mealy ; spines thin, rather distant, very sharp, 

 quite entire, minute. 



Forming thin, spreading patches resembling scattered meal, 

 studded with scattered, acute spines. Sometimes yellowish. 



On rotten wood, especially pine. 



H. argutum. — Substance white, patches vague, scattered, mostly 

 consisting of loosely interwoven hyphae ; spines awl-shaped, acute, 

 unequal, minutely toothed. 



Distinguished by the loose texture of the crust. 



On wood and bark. 



H. stipatnm. — Whitish. Often forming large patches, very thin, 

 minutely powdery, forming an inseparable crust ; spines crowded, 

 blunt, granule-like, minutely toothed. 



Often forming large patches. Sometimes pale dingy yellow. The 

 edge is either sterile or covered with spines. Colour sometimes pale 

 yellowish or very pale buff. 



On rotten wood. 



Irpex 



Somewhat resembling Hydnmn, but the spines are not so uni- 

 formly awl-shaped and pointed, and spring from raised bands or 

 ribs, which sometimes anastomose to form an irregular network. 



Substance often somewhat tough or cartilaginous. Teeth or 

 opines not separable from the cap, and not torn or notched. 



