No. 104.] 65 



white color, sessile pileas, and its lamellse forking or even anastomos- 

 ing near the base in large specimens. 



I find no good characters by which to distinguish Agaricus nephre- 

 tus, Ellis, from this fungus. The spores in this, as well as in P. stria- 

 tulus, p. ?iiger and some others, have a slight depression on one side, 

 ■which makes them broader in one diameter than in the other, and 

 gives them a slightl}^ curved appearance when viewed edgewise. 



Pleurotus septicus, Fr. 



Wood-rotting Agaric. Thin Pleurotus. 

 Agaricus 2^ubesce)is, Sow. 



Pileus small, thin, three to six lines broad, nearly plane, puiesce7it 

 or subpulvertdent, sessile or with a short white pubescent stem or 

 stem-like base, pure white; lamellae rather hroad, sicbdistatit, white ; 

 spores subglobose, .00016 to .0002 in. broad. 



Decaying wood. Ballstoa and Adirondack mouatains. August. 



The clear white color ol P, porrigens is seen also in this species, 

 which may be easily distinguished by its smaller size, nearly pubescent 

 l^ileus, subdistant lamellre and smaller spores. 



Pleurotus atrocseruleus, Fr. 



Dark-blue Agaric. Blue-black Pleurotus. 

 Agaricus aineus, Scha3ff. 



Pileus fleshy with an upper brownish gelatinous stratum, one to two 

 inches broad, convex or nearly plane, reniform dimidiate or obovate, 

 rather tough and flexible, sometimes csspitosely imbricated, sessile, 

 villose-tomentose, dark-blue, blackish, grayish or tawny-brown, flesh 

 soft, whitish ; lamella3 rather broad, close, whitish or yellowish ; spores 

 elliptical, .00025 to .0003 in. long, .00016 to .0002 broad. 



Decaying trunks and branches of beech, alders and poplars. Kar- 

 ner. September. Buffalo. G. W. Clinton. 



I have seen no American specimens with the dark -blue or indigo 

 color shown in the published figures of the European plant, but Fries 

 himself says that the pileus is sometimes brown, so that we have no 

 doubt of the specific identity of our plant. The pileus is covered 

 with a grayish or cinereous villosity, which in small specimens forms 

 a thin uniform velvety pubescence, but in large specimens it is more 

 dense and somewhat tufted. Sometimes it is much thinner on the 

 margin than toward the base of the pileus, and in such specmiens the 

 real color of the pileus is best seen on the margin. This, in large 

 specimens, is often wavy or somewhat lobed. Small, blackish forms 

 frequently resemble large forms of the next species, but are dis- 

 tinguishable by the paler color of the lamellte. The plant readily 

 revives on the application of moisture. 



Pleurotus atropellitus, n. sp. 



Black-skinned Agaric. 



Pileus very thin, three to eight Imes broad, rather tough, flaccid, 

 resupmate or reflexed and lateral, convex or nearly plane, suborbicular 

 obovate or reniform, villose-tomentose except on the margin, sessile or 



[Assem. Doc. No. 104.] 9 



