PREFACE TO FIRST EDITION. 



THE collection of specimens of Mycetozoa in the 

 Herbarium of the British Museum has been greatly 

 increased in recent years. The additions include 

 the large collection of the late C. E. Broome, bequeathed by 

 him to the Museum, and that of H. W. Ravenel, purchased 

 from his widow. 



It was necessary to make a critical examination of the 

 whole of the materials in the Herbarium. Mr. Arthur Lister, 

 who has devoted much attention to these organisms, was 

 fortunately able to undertake this work ; and he agreed at 

 the same time to prepare a monograph of the whole class 

 based on this examination. 



This volume, the result of his labours, contains descriptions 

 not only from the specimens in the Museum, but also from 

 types in various public and private Herbaria, and from his 

 own rich collection. Mr. Lister has generously presented a 

 large series of specimens to the Museum, so that the Herbarium 

 now contains types of all the species described by him in this 

 monograph. 



The volume is fully illustrated with plates mechanically 

 reproduced from faithful water-colour drawings by the 

 author and by his accomplished daughter, to whom in the 

 Introduction Mr. Lister acknowledges his obligations. 



WILLIAM CARRUTHERS. 

 November, 1894. 



