1926] 



BURT THELEPHORACEAE OP NORTH AMERICA. XV 175 



species into 4 workable groups nearly equal in numbers, as 

 presented in the following key to the species. Each of these 

 groups is subdivided to such degree as seems desirable largely 

 by spore characters into minor groups of so few species that the 

 characters of the component species of any group may, and should, 

 all be considered in determining the probable species of the speci- 

 men in course of identification. The extensive lists of speci- 

 mens studied, with their localities where collected, and present 

 preservation in published exsiccati and herbaria, afford material 

 for checking up one's own determinations. Determinations as 

 published should correct earlier tentative determinations com- 

 municated to my correspondents. 



Throughout this work technical color terms are those of Ridg- 

 way's ' Color Standards and Nomenclature/ There was little 

 knowledge available as to the color of specimens when growing, 

 but since the time-consuming task of determination is usually 

 with dried specimens collected many years ago and often more or 

 less faded or yellowed, my record of the color of the dried speci- 

 mens should be the more helpful to the chief users of this work. 



Accounts of the species of the genera Tremellodendron, Etch- 

 leriella, Sebacina and Septobasidium were included to set off more 

 sharply the true Thelephoraceae to which the species of these four 

 genera are so similar in aspect that they were commonly known 

 under their original names as species of Thelephoraceae. By 

 treating these genera and Lachnocladium in the present work, the 

 student had at hand a systematic account of all North American 

 fungi of thelephoraceous aspect. The matter on those genera 

 could otherwise have been included in my recent publications: 

 'Some North American Tremellaceae, Dacryomycetaceae and 

 Auriculariaceae ' and 'North American species of Clavaria.' 



To all whose names have been recorded as collectors and con- 

 tributors of specimens and to botanical institutions whose speci- 

 mens are cited and which have afforded me facilities for the study 

 of their herbaria I am deeply indebted. Without their aid but 

 little could have been done. 



