40 NEW YORK STATE MUSEUM 



Pileus 2.5-3.5 cm broad; stem 5-8 cm long, 1-3 mm thick. 



Gregarious. Low ground under trees. Stow, Mass. September. 

 S. Davis. 



This slender species closely approaches some species of Leptonia 

 in general appearance. This character has suggested the specific 

 name. The more or less decurrent lamellae throw the species into 

 the genus Clitopilus. It differs from Clitopilus vilis Fr. 

 by the color of the pileus and by its larger spores, and from 

 C . subvilis Pk. by the color of the pileus and its squamulose 

 center. In the dried state the pileus and stem are black and the 

 margin of the pileus is sulcate striate. 



Pileus tenuis, conicus vel convexus, umbilicatus hygrophanus, 

 centro umbilicoque squamulosus alibi glaber, udus, castaneus, 

 margine striatulatus, in umbilico ater ; lamellae latae, late adnatae 

 vel decurrentes, distantes, albae, demum incarnatae, interdum trans- 

 verse venosae ; stipes gracilis, aequalis, vel leviter seorsum attenu- 

 atus, fibrillosus, rectus farctus cavusve, brunneus, basi abundante 

 albo tomentoso ; sporae subglobosae, angulares, uninucleatae, 10-12 



X 8-10 fl. 



Pileus 2.5-3.5 cm latus ; stipes 5-8 cm longus ; 1-3 mm crassus. 



Coryneum effusum 



Forming thinly effused indefinite black patches on wood, mycelium 

 subhyaline, sporophores slender, often flexuous and tapering down- 

 ward, subhyaline, 12-30 fi long; spores oblong or subfusiform, 

 straight or slightly curved 2-septate when mature, the central cell 

 black, the terminal cells subhyaline, one or both finally subtruncate, 

 20-28 x 10-12 fi, the central cell 10-12 p long. 



Wood of western cottonwood, Populus occidentalis 

 Rydb. Stockton, Kan. March. E. Bartholomew. 



Differs from tvpical species of Coryneum in forming no definite 

 acervuli or subcutaneous erumpent heaps but in developing in 

 effused patches on decorticated wood. 



Coryneum tenuiter effusum, in ligni superficiei areas atras in- 

 definitas f ormans : sporae oblongae vel subfusif ormae, rectae vel 

 leviter curvae, in maturitate biseptatae, loculo centrale atro, ter- 

 minalibus subhyalinis, saepe truncates, 20-28 x 10-12 /x, loculus 

 centralis 10-12 p longus. 



Diatrype tumidella 



Stroma orbicular, plane or convex, 1-2 mm broad, surrounded 

 by a black line which penetrates to the wood, erumpent and 



