PREFACE. 



will always rank, with the ' Corallines ' of Ellis, 

 amongst the classics of natural-history literature. 

 As a manual for the use of the student, however, it 

 has long ceased to be of value ; nor is there any work 

 in existence that contains a complete account of the 

 British Hyclroida. The place therefore is vacant, 

 which the present work aspires to fill. I have endea- 

 voured to make it a full and faithful exposition of our 

 present knowledge, and to do for the students of this 

 day what Johnston's ' History ' accomplished for those 

 of his own generation. It is certainly time that the 

 remarkable results attained since he wrote, and now 

 widely scattered, should be presented in a connected 

 form and made available for general use, and that the 

 difficulties should be removed which interfere with the 

 cultivation of one of the most delightful branches of 

 Natural History. 



This Preface might have been very brief, had not 

 the kindness of many friends and fellow workers laid 

 me under heavy obligations, which it is a duty and a 

 pleasure to acknowledge ; without such cooperation, 

 indeed, I could not have accomplished my work. 

 Foremost amongst those to whom I have been in- 

 debted for help, it is right that I should place my 

 lamented friend the late Mr. Alder, one of the ablest 

 of British naturalists, and one of the most amiable 

 and upright of men. In the course of a long corre- 

 spondence, extending over many years, and relating 

 chiefly to our favourite studies, I have had the oppor- 

 tunity of profiting largely by his extensive knowledge, 



