PREFACE 



THE present work, which was undertaken at the suggestion of the 

 former Director, Sir E. Kay Lankester, K.C.B., F.R.S., covers but 

 a small proportion of the ground to be gone over in making a 

 Catalogue of the Chaetopoda or even of the Polychaeta. 



Although the volume appears as " Part I " of a more general 

 catalogue, its selection for the first place was a fortuitous 

 circumstance, depending on the fact that Dr. J. H. Ash worth, the 

 author, had already devoted special attention to the Arenicolidae 

 when the idea was first projected. The Family in question was thus 

 not chosen because it was supposed to come naturally at the 

 beginning. But as circumstances have placed it there, it has been 

 thought advisable to devote some pages to an introductory survey of 

 the history and classification of the Chaetopoda, and in particular 

 of the Polychaeta. Morphological characters are largely em ployed 

 by the author in characterising the species. 



Mr. F. Jeffrey Bell, whose official duties in the Museum include 

 the care of the specimens of Chaetopoda, has devoted much time to 

 the editing of this Volum,e. 



The continuation of the series of volumes on Chaetopoda is not 

 at present provided for, but it is hoped that opportunities will 

 present themselves from time to time of continuing the series which 

 has been begun by Dr. Ashworth. 



SIDNEY F. HAEMER, 



Keeper of Zoology. 



BRITISH MUSEUM (NATURAL HISTORY), 

 LONDON, S.W., 



November, 1912. 



