1920] 



BURT THELEPHORACEAE OF NORTH AMERICA. XII 197 



tomentum; no conducting organs present; cystidia rather few 

 and scattered, heavily and coarsely incrusted on the peripheral 

 half, conical, 30-75X12-25 m, usually colored under the incrus- 

 tation, confined to the hymenium; slender, flexuous paraphyses 

 2\ n in diameter are abundant in the hymenium; spores hya- 

 line, even, 4J-8X3-4 ^ but few found. 



Resupinate on under side of limbs over areas up to 25X3J 

 cm., and reflexed along both sides 1 2J cm. 



On under side of fallen limbs of frondose species. Florida, 

 West Indies, Mexico, Colombia, and Brazil. October to May. 

 Probably common. 



S. papyrinum belongs in the group with S. umbrinum and S. 

 albo-badium; resupinate specimens of these species require ex- 

 amination of sectional preparations for accurate determina- 

 tion. The specimens which have been distributed by Ravenel 

 and by Ellis in their exsiccati as S. papyrinum are S. umbrinum. 

 In its reflexed stage, S. papyrinum is much more broadly reflexed 

 than S. umbrinum and is concentrically sulcate; its cystidia are 

 heavily incrusted and from 12 to 25 p in diameter by 30 to 75 n 

 long, while those of S. umbrinum are much longer in proportion 

 to their diameter and often can be followed from deep in the 

 subhymenium, taper so gradually and bear so little incrustation, 

 and are so uniformly colored that some mycologists have 

 regarded them as setae, although they do not satisfy the defini- 

 tion of setae. The cystidia of S. papyrinum are concolorous 

 with the hyphae under the incrustation. S. albo-badium has 

 cystidia heavily incrusted but smaller than those of S. papyrinum 

 . and not colored. 



On account of their structure, I have included in S. papyrinum 

 the Cuban specimens listed by Berkeley & Curtis as S. mem- 

 branaceum, for I find nothing to show that these specimens were 

 ever compared with the type of the latter in Herb. Willdenow 

 and collected on the Isle of Bourbon in the Indian Ocean; there 

 is nothing in the original description of S. membranaceum to 

 show that this may not be more closely related to S.fasciatum 

 than to S. papyrinum. I have referred to S. papyrinum, as um- 

 bonate-sessile forms, the specimen from Nicaragua distributed 

 in Smith, Central Am. Fungi, 94, and a collection from Cuba by 

 Underwood & Earle, 1584, which are cited below; these speci- 



