V1U PREFACE. 



of the species where it seemed especially desirable that 

 this should be done. Fifthly, to supply a table of 

 Geographical Distribution. Sixthly, to furnish a Cata- 

 logue of all works and papers published on the 

 Sponges, so far as known to him; and, Lastly, to 

 add a brief Appendix which should make known to 

 Spongologists those British Sponges which have been 

 described, but to which no reference was made in the 

 writings of Dr. Bowerbank. 



Dr. Bowerbank marked out a certain course for 

 himself, namely, to work out conscientiously and fully 

 the organization and intimate structure of the sponges, 

 and upon the observations thus made to establish a 

 system of classification. He was a pioneer who 

 struck out a new line ; others following in his footsteps 

 profited by his work ; and while they agreed with him 

 in regarding minute microscopic structure as the basis 

 of classification, looked for generic characters rather 

 in the shapes assumed by the various spicula than, 

 as Bowerbank had done, in the mode of arrangement 

 of those spicula and manner in which they form the 

 skeleton. This must of course be regarded merely as 

 a very broad statement of the essential difference of 

 views. Our author, as he had begun alone, so went 

 on alone in his own way, not so much disregarding 

 as seldom or rarely noticing the views of others. It 

 is for this reason that hardly any synonymy will be 

 found in the previous volumes of this work. To such 

 a great extent did the author disregard references 

 that any reader taking up his volumes would imagine 

 that many of Dr. Bowerbank's own species dated from 



