1914] 



BURT — THELEPHORACEiE OF NORTH AMERICA. Ill 359 



by the absence of a hyphal subiculum over the area on which 

 the fructifications are distributed, and by the less cyhndric 

 form of fructifications of Cyphella. Cyphella is allied to Mem- 

 lius by C. muscigena and also to Craterellus by this species, speci- 

 mens of which were described as a Craterellus. 



A few species of Cyphella are common and widely distributed, 

 but most of our North American species are apparently ex- 

 tremely local and are known only from their respective type 

 collections. The lack of specimens available for carrying 

 about to compare with types has been a serious disadvantage 

 in my study of this genus. Basidia and basidiospores have not 

 as yet been found for some species which, although originally 

 referred to Cyphella, have to be regarded as even doubtful Basi- 

 diomycetes. I have supplemented the original descriptions with 

 measurements of dried fructifications and with such data in 

 regard to basidia and spores as the specimens afford. In the 

 case of very scanty types, the few fructifications are too precious 

 for gross comparison to be used for microscopic study. For 

 such species, it seems to me that the descriptions should stand 

 on the original data, without prejudice, until new collections 

 become available. Such imperfectly known and partially de- 

 scribed species are grouped together under the heading ''Species 

 Imperfectly Known." Cyphella convoluta Cke., C Cupressi 

 (Schw.) Fries and C. subcyanea Ell. & Ev. are excluded species. 



Key to the Species 



Fructifications sulphur-colored; hymenium even; spores 45x25-8 n l.C. sulphurea 

 Fructifications sulphur-colored; hymenium minutely pitted; spores 6-8 x 



3-4 M 2. C. loeta 



Fructifications white or whitish; on mosses 1 



Fructifications white; not on mosses 2 



Fructifications neither white nor sulphur-colored 3 



1. Fructifications helmet-shaped; hymenium shghtly wrinkled; spores 10 x 



8 /i S. C. galeata 



1, Fructifications flattened, irregular in form, sometimes stipitate; spores 3-5 



X 2-3 n 4- C- muscigena 



1. Fructifications seated upon or developing from webby strings of mycehum 



5. C. arachnoidea 

 2. Fructifications villose, not easily crushed, with a firm base or a short 



stem; spores 12-18 x 6-6| tx 6. C. Tilioe 



2. Fructifications villose, easily crushed, sessile; spores 10-12 x 5-7 n 



7. C. villosa 

 2. Fructifications whitish, minutely webby-hairy, easily crushed, sessile; 



spores 8-13 x 4 /i 8. C. caricina 



