24 6 The Irish Naturalist. 



ginei. and AUuviacei, form, however, an exception to this 

 rule. Recent investigations have so completely revolutionized 

 their nomenclature and arrangement that it has been thought 

 necessary to give a complete list of all the species hitherto 

 met with in the district. The extremely evanescent nature 

 of many fungi causes a twofold difiiculty in their studj^ 

 Firstly, in a given district, at a given period, a species may 

 occur abundantly of which no trace was visible a week before, 

 or would be a week after. Secondly, they decay very rapidly, 

 and hence when necessity arises — as it constantly does — of 

 obtaining the opinion of another worker, by the time the 

 specimen reaches him, it may be unrecognizable. 



The list appended hereto contains about 245 species 

 not included in previous lists, bringing the total number up 

 to nearly 780. Of the aforesaid 245, eighty belong to the 

 Agaricini, twenty- six to eighteen other orders of Hymeno- 

 mycetes. Gasteromycetes (including Myxomycetes) number 

 thirteen. Coniomycetes, amongst which are the Uredinei 

 and Ustalaginei, forty-two. Hyphomycetes (including Pero- 

 nosporese) twenty-four. Discomycetes, thirty-six. Pyreno- 

 mycetes, twenty. The Agaricini generally are fairlj^ well 

 represented in the district, but the genus Corti?iarius is con- 

 spicuous by its comparative absence, and the same maybe said 

 of the pink-spored division of the agarics, and of the woody 

 or coriaceous genera. Two species of Panus are, however, re- 

 corded for the first time. Several new Polyporei are added to 

 the list, and a few of other orders of the Hymenomycetes. 



Amongst the Gasterom3^cetes, the occurrence in Powerscourt 

 of Cynophallus caninus may be noted. Several additions are 

 made to the Myxogastres, which are fairly represented, 

 though perhaps not so numerously as might be expected, 

 considering the dampness of the climate. Not a single new 

 subterraneous gasteromycete is recorded, nor is there any- 

 thing to add in the corresponding group of Tuberacei, or 

 Truffles. 



The Uredinei and Ustilaginei (Rusts, Brands, and Smuts), 

 are, perhaps, the most numerous, relatively, of any of the 

 groups, no fewer than seventy-seven species being recorded, 

 and it can scarcely be doubted that careful searching would 

 reveal many more. Amongst the Hyphomj^cetes, a very 

 curious minute form occurred on decaying passion-flower 



