[Vol. 13 

 322 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Study of the type of Zygodesmus pallidofulvus in N. Y. State 

 Mus. Herb, shows the species to be an Hypochnus specifically the 

 same as H . subferrugineus, which therefore becomes a synonym. 



H. Rhacodium Berk. & Curtis in herb, under Stereum, n. sp. 



Type: in Mo. Bot. Gard. Herb., Farlow Herb., and Kew Herb. 



Fructifications effused, very thick, crust-like and brittle when 

 dry and fuscous or dusky drab externally and throughout, col- 

 liculose, not cracked, the margin unknown; in section 1H~3 mm. 

 thick, fuscous, composed (1) of a layer 3^-2 mm. thick next to the 

 substratum, fibrous and tow-like, composed of loosely interwoven, 

 thick- walled, rigid hyphae up to 6 y. in diameter, not incrusted, 

 rarely nodose-septate, and (2) of a crust-like hymenial portion, 

 composed of 1 or 2 layers with hyphae erect, densely crowded, 

 colored, 4-5 [i in diameter, not incrusted, not nodose-septate, 

 bearing basidia; no gloeocystidia nor cystidia; basidia with at 

 least 2 sterigmata demonstrated; spores concolorous with the 

 hyphae, acuieate-tuberculate, somewhat angular, the body 6-7 (i 

 in diameter. 



Fructifications probably large known from fragments up to 

 2 cm. long, Y^ cm. wide. 



On under side of decaying logs of apparently a frondose species. 

 Pennsylvania. 



H. Rhacodium has the aspect of a thick, dark fuscous, effused 

 Hypoxylon. The hyphae of the under layer are brittle when dry 

 so that the hymenial crust is very likely to split away from the 

 substratum through this brittle layer. The specimens in Kew 

 and Farlow Herbaria, communicated by Michener through 

 Curtis, consist of the hymenial crust. Michener's own speci- 

 men, now in the Mo. Bot. Gard. Herb., has the whole fructifica- 

 tion to the woody substratum. This species is related to H. 

 umbrinus. 



Specimens examined: 

 Pennsylvania: E. Michener, type, No. 1435 to M. A. Curtis (in 



Mo. Bot. Gard. Herb., 5095, in Farlow Herb., and Kew Herb. 



as Curtis Herb., 4061, under the herbarium name Stereum 



Rhacodium). 



