4 DECADES OF FUNGI. 



guished by its thicker flexible substance, which is separable 

 from the matrix. 



106. Hexagonia similis, n. sp. ; pileo sublaterali suberoso- 

 coriaceo tenui explanato e pallido ligneo-fulvente, zonis 

 postice crebris antice paucioribus rugosis, lineis prominen- 

 tibus hie illic notatis, glabro sericeo-nitido ; poris parvis 

 pallidis intus primum pruinosis ; margine hymenii sterili. 

 Australia. Gathered by one of the officers of the Beagle. 

 Pileus sessile, or furnished with a very short orbicular 

 stem, 3 inches long, A\ inches broad, suberoso-coriaceous, 

 slightly flexible, thin, especially towards the margin, re- 

 peatedly and sometimes closely zoned, rather rugged and 

 marked with a few raised lines which, however, do not form 

 bristles, of a brownish wood-colour, smooth with a satiny 

 lustre ; the extreme edge only minutely velvety, but soon 

 becoming smooth. 



Hymenium paler than the pileus, rather uneven ; pores 

 subhexagonal, small, l-50th of an inch in diameter, pale at 

 first, pruinose within. Substance of the same colour as the 

 pileus. 



This species is allied to H. polygramma, Mont.; though 

 the pileus is thicker and the pores much smaller. In 

 H. poly gramma there appear to be no finer zones ; but in the 

 present species, in an early stage of growth, the pileus is 

 very closely zonato-striate. Its relation to other species is 

 more distant. It is possible that in every species of Hexa- 

 gonia there are distinct varieties, exhibiting pores of various 

 sizes, of which I fancy that I have some evidence. In this 

 case, the species will require reduction, and this will be 

 registered under H. polygramma, for there will be no other 

 point of much consequence, except that of the barren margin 

 of the hymenium and the rather convex than concave pileus. 

 The fine zones behind are at length concealed in the course 

 of growth, by an anamorphosis of the external cellular 

 tissue. 



107- Polyporus brunneo-leucns, n. sp.; imbricatus, postice 



