INTRODUCTION 15 



Congress held at Cambridge, England, has adopted this plan. To attempt to 

 stabilize many of the early names on the basis of species originally included 

 in them would be impossible, as the type species in some instances are not 

 determinable, and in others the adoption of the original species would lead 

 to such a different application of the names from the present that it would 

 cause much change and confusion. Further discussion of this matter with 

 examples may be found in the paper by Shear on "Mycological Nomencla- 

 ture" (1929). 



In view of what has just been said, the selection of the type of a genus 

 is of the first importance. In order to avoid change and ensuing confusion 

 as far as practicable, the type species should be chosen from the best known 

 or more important species generally included in the genus at present. In 

 selecting the generic names adopted in the present treatment, general usage 

 has been followed in the case of all important genera, instead of priority of 

 publication. An attempt to follow the method of fixing generic names in all 

 cases by using the first or in fact any one of the species originally included 

 by the first user of the name would result in many changes from the present 

 application of familiar and well-established names and combinations. 



As a matter of fact, the application of the principle of priority has 

 failed to secure uniformity and stability in botanical nomenclature and if 

 applied strictly to the fungi, this principle would produce a condition 

 approaching chaos (cf. Shear, Science 60:254 1924). Since the application 

 of the generic name depends upon the type species and many genera contain 

 species that are not congeneric, it is desirable to select a type that will cause 

 the least change. This in many cases necessitates the choice of a species 

 not included by the original author of the genus. Otherwise, many 

 names would need to be discarded, as the original species is indetermi- 

 nable or unknown, or applied to a totally different group from the present 



one. 



The recently revised International Code recommends this method of 

 fixing generic types, and an international committee of mycologists has been 

 appointed for the purpose of carrying out this plan. It is hoped that most 

 of the types selected here will be found acceptable and generally adopted. 

 The necessary changes can be made in the next edition. 



Synonyms 



The synonyms given in the list of types (p. 233) have been obtained 

 in four different ways. The first and most important of these has naturally 

 been by the labors of mycologists as recorded in the more recent literature, 

 in which the revisions of Hoehnel, Theissen, Sydow and Petrak occupy 

 the most conspicuous place. No attempt has been made to duplicate the 

 synonomy already given in the "Sylloge Fungorum" or in Zahlbruckner's 

 monograph of the lichens, but in some of the smaller groups such as the 

 phycomycetes and the rusts and smuts, the synonomy is fairly complete. 

 The assignment of type species has been a second source of synonyms. 



