72 NEW YORK STATE MUSEUM 



I millimeter broad, as shown in plate i, figure i. This margin is 

 fairly regular, and not fimbriate. The thickness of the hymenium- 

 producing region in dried plants is about half a millimeter in the 

 types but in other collections as much as 3 mm. This thickness is 

 made up of a very thin but conspicuous subiculum and the rather 

 short tubes. The mouths of the tubes are angular or subangular 

 and with a diameter of 5 to 6 to the millimeter. The dissepiments 

 are rather thin but remarkably entire. The hymenium often and 

 perhaps typically shows a decided silky luster when viewed in oblique 

 positions. 



The spores are ellipsoidal or inclined to elliptical and hyaline 

 (plate I, figure 2). They are 3 to 4 /* long and 2 to 3 /a broad. 

 There are many conspicuous encrusted cystidia in the hymenium, 

 but in some collections they appear to remain embedded in the 

 tramal tissue and not project beyond the basidia. In other collec- 

 tions they project very conspicuously (plate 2, figure la) and 

 usually obliquely into the lumen of the tubes. They are best seen 

 in vertical sections of the hymenium as shown in plate 2, figure 2. 

 In cross sections they are often to be identified only by their cross 

 section views (plate 2, figure i-b) as even where they do project into 

 the tubes they do so obliquely and so are cut crosswise in such sec- 

 tions. In macerated or teased preparations their true nature is 

 easily made out. They are simply the enlarged and encrusted ends 

 of ordinary hyphae as shown in plate i, figures 3 and 4. They meas- 

 ure 60 to 80 /A in length and are 7.5 to 10 fx thick. The hyphae of 

 the trama and the subiculum are rather compactly arranged, and 

 are colorless, only rarely branched, sometimes quite flexuous though 

 ordinarily only moderately so, and no cross walls are visible. They 

 vary in diameter from 2 to 4 /a. There are no clamp connections 

 (plate I, figures 5 and 6). 



Llo}d has stated (Mycological Notes, 2: 374. 1908) that this 

 species is the same as P o r i a e u p o r a Karsten. From unau- 

 thenticated specimens I have seen I am of the same opinion. Also 

 P. nit id us A. & S. (ex Egeland, Norsk. Res. Poresv. p. 151) 

 is apparently a closely related species. P o r i a m y c e 1 i o s a and 

 Poria fimbriatella, both described by Peck, are some- 

 what similar but of different coloration and with smaller spores. 

 Also the former species is without cystidia and has distinct cross 

 walls and clamp connections in the hyphae. 



Poria attenuata appears to be quite frequent in the east- 

 ern United States, but among a large series of western collections 

 from various localities and different collectors this fungus has not 



