POPtOTHELIUM. 177 



adnate, thin, crustaceous, rather mealy ; warts crowded, sub- 

 globose, minute, often collajDsing at the apex, unequal. 



Grandinia crustosa. Fries, Hj-m. Eur,, p. 627; Stev., Brit. 

 Fung., p. 256. 



On bark of willow, pine, &o., and on Polyporus versicolor. 

 Often forming a crust that extends for several inches. 



Grandinia mucida. Fr. 



Waxy and somewhat gelatinous, effused, subinnate, pale 

 dull yellow ; hymenium crowded with rather large, unequal, 

 hemispherical, soft granules. 



Grandinia mucida, Fr., Elench., p. 217; Stev.,Fung., p. 255. 



On rotting wood. Effused for several inches. Subgela- 

 tinous when moist, corrugated when dry. 



POEOTHELIUM. Fries (emended), (figs. 14, 15, p. 149.) 



Thin and entirely resupinate, the surface covered with 

 small warts that eventually become more or less perforated at 

 the apex, basidia tetraspoi'ous, borne on the outer surface of 

 the warts as in Hydnum. 



Porothelium, Fries, Obs. ii. j). 272 ; Stev., Brit. Fung., 

 p. 231. 



The present genus was placed by Fries in the Folyporeae, 

 and considered as showing some afSnity with Fistulina in the 

 structure of the pores, which are at first solid, then exca- 

 vated, but in reality the basidia do not line the pores, as in 

 the Polyporeae, but the hymenium covers the outer surface of 

 the warts or projections as in the Hydneae, and the species 

 are very close to certain of the resupinate Hydnums that 

 have the tips of the spines more or less excavated. 



Porothelium Keithii. B. & Br. 



ClosL'ly adnate, inseparable, thin, at first subgelatinous, 

 forming patches 1-2 in. across, pale umber, margin very 

 thin, subpulverulent ; warts scattered, short, at length col- 

 lapsing, gelatinous in the centre ; spores linear-oblong, 

 5x2//,. 



Porothelium Keithii, B. & Br., Ann. Nat. Hist., n. 1084; 

 Stev., Brit. Fung., p. 231. 



On dead fir. Distinguished amongst British species by 



VOL. I. N 



