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PREFACE 



In the Herbarium of the New York Botanical Garden are the 

 large private collections of Mycetozoa made by the late J. B. 

 Ellis, and the late Dr. W. C. Sturgis. These include many speci- 

 mens collected by the earlier American students, Bilgram, Farlow, 

 Fullmer, Harkness, Harvey, Langlois, Macbride, Morgan, Peck, 

 Ravenel, Rex, Thaxter, Wingate, and others. There is much 

 type and authentic material. There are also several thousand 

 specimens received from later collectors, and found in many parts 

 of the world. During the past twenty years my associates and I 

 have collected and studied in the field more than ten thousand 

 developments in eastern North America. The larger part and 

 best of these have been placed in the Herbarium. The entire 

 collection is large enough to enable one to form a proper idea of the 

 distribution in North America; and the geographical records, as 

 given, have been taken therefrom unless preceded by an asterisk. 

 The latter refer to reports by other authors, and it is possible a 

 few of them are erroneous, particularly in instances of single re- 

 ports of rare or obscure forms. Reports of rare species, published 

 by students who it is believed have had no access to authentic 

 material to verify their determinations, have been ignored. 



The classification and division into families and genera follows 

 that of Lister, which has been found more workable than others. 

 The species within a genus are arranged, generally, in the order 

 of their affinities, which assists in locating a species. The keys 

 occasionally depart from this order when more prominent charac- 

 ters are used. Complete lists of synonyms are not given. They 

 may be found in the monographs of Lister, and of Macbride, and 

 it is unnecessary to repeat them. The colors of the spores are 

 given throughout as they are seen in the microscope by trans- 

 mitted light when separated, and with magnifications of 600 to 

 800 diameters. 



The following words are used after Herbarium numbers to 

 designate important specimens. Type or cotype: the particular 

 specimen used for the original description. Type or cot^'pe 

 material: material distributed by an author as part of the type or 



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