PREFACE 



After the publication in 1924 of my book on the Echinoderms 

 C'Pighude") in the series DanmarWs Fauna I was invited to 

 translate it into EngUsh, in order that the work might become 

 more generally useful to English zoologists, to whom the language 

 would naturalh^ be a serious hindrance for making full use of 

 the Danish edition of the book. I was very glad to receive the 

 proposal and also felt quite willing to accept it. However, it 

 very soon became evident that a simple translation would not 

 do. The Danish work contains only the species found in the 

 Danish and Scandinavian seas ; but there are several species 

 of echinoderms found in the British seas which do not reach 

 the Scandinavian seas, and, therefore, are not included in 

 the Danish work. It was clear that, if a similar book were to 

 be A\Titten on the British echinoderms, it must be extended so 

 as to include all the species occurring in the British seas — not 

 the Httoral forms alone, but also the rather numerous deep-sea 

 forms known from off the west and north coasts, as they are 

 ah-eady included in Bell's Catalogue of the British Echinoderms 

 and in several other works dealing with the British echinoderm 

 fauna. 



But where to put the Unlit ? To take a certain distance from 

 the coast, e.g. 10 miles or more, or a certain depth, e.g. the 1000 

 or 2000 metre line, Avould be equally arbitrary and contrary 

 to natural conditions. The only reasonable course has seemed 

 to the author to be this : to include the whole of the deep-sea 

 fauna known from off the British coasts down to the greatest 

 depths. 



Studying this deep-sea fauna, it was found over and over 

 again that species originally discovered in the Bay of Biscay 

 and off the Azores, and even as far south as Madeira, the Canaries, 



