19S1] The Thelephoraceae of North Carolina 173 



connected, incrusted (so as to look very rough-walled) hyphae, 4.2jx. 

 thick; hymenium about 18[j. thick, made up entirely of young and 

 old basidia, which are clavate, 4:.8[l thick, with four minute sterig- 

 mata; no cystidia, but at base of the hymenium is a layer of crys- 

 tals which KOH does not dissolve entirely. 



Spores white, short-elliptic, hyaline, 2.5-3.5 X 3.8-5[jl. 



When compared with specimens of C. arachnoideum from New 

 Jersey (Ellis and Everhart, Fungi Columbiana No. 309) at New York 

 Botanical Garden, our plants agreed exactly and Dr. Burt has kindly 

 confirmed the determination. 



4235a. On very rotten, decaying, deciduous wood, March 25, 1920. 

 Common on wood and bark. Curtis. 



7. Corticium vagum B. &. C. 



Corticium hotryosum Bres. Ann. Myc. 1: 99. 1903. 



Plate 33 



Entirely resupinate, pulverulent-looking, margin indeterminate; 

 easily separable from the substratum when wet, and with an open 

 wefty structure that resembles a mold; color when wet, hght slate, 

 drying to a yellowish gray. Structure in section about 240ex thick, 

 consisting of very loosely packed, very large (7.4[x thick,) consider- 

 ably branched, frequently septate hyphae without clamp connections 

 which are yellowish towards the substratum. 



Spores subeUiptic (flat on one side, curved on the other), pointed 

 at each end, 3.8-5.5 x 7.5-1 l[x. Basidia simple, very pecuhar, 

 hardly distinguishable from the hyphae and not forming a distinct 

 hymenial layer, 7.4-9 X 18-25[jl, with two, four or six curved sterig- 

 mata. No cystidia. 



The small group of Corticiums to which this species belongs is 

 pecuhar in the undifferentiated condition of the fruiting surface. 

 There can scarcely be said to be a hymenium any more than in a 

 mold. The plant is at times parasitic, again saprophytic. Burt 

 (1. c.) has studied it along with two other related species and his 

 description agrees substantially with ours. Hypochmts Solani, 

 Corticium Solani and Rhizoctonia Solani are the same as this. Our 

 plant also agrees in all important particulars with Bresadola's de- 

 scription of his species and with the more detailed description by Miss 

 Wakefield (Trans. Brit. Myc. Soc. 4: 117. 1913). 



