PREFACE. ix 



the Orkneys and Shetlands, containing the types of some of 

 the most interesting of our native species. To Mrs. Brett, 

 of Tenby, I have in like manner to return my best thanks 

 for repeated contributions of new and interesting species ; 

 and I am also greatly indebted to my friend Mr. Bean, of 

 Scarborough, who has, with his accustomed kindness and 

 liberality, contributed numerous specimens to my cabinet, 

 and has placed the whole of his rich collection of sponges 

 at my service for examination and description. 1 am also 

 greatly obliged to the late Mrs. Dr. Bucldand for many 

 interesting specimens collected by her at Sark and Guernsey. 

 My late friends, Mr. Robert Brown and Mr. Lucas Barrett, 

 have also favoured me with valuable contributions of speci- 

 mens. I have also to thank Dr. Battersby, of Torquay, for 

 similar kind assistance. To Mr. H. J. Carter, late of 

 Bombay, I am greatly indebted for an abundant supply of 

 the species of Spongilla so ably described by him in the 

 'Journal of the Bombay Branch of the Royal Asiatic 

 Society,' No. XII, 1849, and for an interesting collection 

 of sponges from the neighbourhood of Aden. To my 

 friend Mr. George Clifton, late of Freemantle, Western 

 AustraUa, I am especially grateful, for the numerous and 

 laTge collection of the sponges of that locality with which 

 he has favoured me, through which, from their fine state 

 of preservation, I have obtained many beautiful varieties 

 of organization that I was before imacquainted with. To 

 Mrs. Collings, the lady of the Seigneur of Sark, I have also 

 to return my best thanks for much kind information and 

 assistance regarding the marine productions of the Channel 

 Islands. Mr. Hugh Cuming has also my best thanks for 

 having assisted me in obtaining many interesting specimens, 

 and especially for the kind and liberal use he has allowed 

 me of his beautiful specimen of Bu^lectella aspergillum, 



