INTRODUCTION. Vll 



constant need for caution and reflection. Before the beginner yields 

 to the temptation of describing " new species," which is easy enough, 

 let him first gain the knowledge and experience which will teach 

 him how one form links on to another, and thus avoid the undue 

 multiplication of synonyms. 



Till quite recently our collection of Echinoderms was particularly 

 poor in British specimens ; that we have now a splendid series illus- 

 trative of the fauna of the West coast of Scotland is due to Dr. John 

 Murray, as the repeated citation of his name will abundantly show, 

 and he deserves our sincerest thanks ; the Hon. Alfred E. Gathorne- 

 Hardy has from time to time presented us with valuable and well- 

 preserved specimens from Loch Craignish : while from the East 

 of Scotland I have been much aided in forming a collection by 

 Dr. Sutherland of Invergordon, Mr. W. Duncan of Montrose, and 

 Mr. George Sim of Aberdeen. Eor specimens from the East coast 

 of Ireland we have been aided by the gifts of the Belfast Natural 

 History Society; I owe to the friendly kindness and scientific 

 enthusiasm of Professor A. C. Haddon numerous opportunities of 

 inspecting, and ofttimes keeping for our Collection, the results of 

 aredgings in the Irish Seas, made under the auspices of the Royal 

 Irish Academy or the Royal Dublin Society. The deep-sea expe- 

 dition of 1889, which Dr. Giinther induced the Rev. W. S. 

 Green to undertake in the ' Flying Fox,' resulted in a very valuable 

 and instructive series of Echinoderms. My thanks are also due to 

 Lord Walsingham, F.R.S., Prof. Herdman, F.R.S., Prof. Mcintosh, 

 F.R.S., Mr. Howse of Newcastle, to Mr. G. C. Bourne, formerly of 

 the Marine Biological Laboratory at Plymouth, and Dr. Grenfell, for 

 assistance offered and given. Mr. R. L. Spencer has repeatedly 

 sent me objects of interest from the Channel Islands. I have kept 

 to the last, because I desire it to be mentioned by itself, the name of 

 the Rev. Canon Norman, F.R.S., whose interest in the marine 

 British fauna is such that, in the midst of arduous and responsible 

 duties, he has always found time to answer the numerous questions 

 I have asked him, or to lend or give me specimens which would help 

 me in my work. 



As many of our species are more familiar to Scandinavian natu- 

 ralists than ourselves, I have had to ask for, and have received, 



