Art. XV. — Catalogue of Non-Calcareous Sponges collected 

 by J. Bracebridge Wilson, Esq., M.A., in the 

 Neighbourhood of Port Phillip Heads. 



Part III. 

 By Arthur Dendy, D.Sc, 



Professor of Biology in the Canterbury College, University of New 

 Zealand; Corresponding Member of the Eoyal Society of Victoria. 



Introductory Remarks. 



The present instalment of the catalogue deals with the families 

 Axinellida, Sitberitidce and Spirastrellidce, together with a few 

 specimens which, owing to the difficulty of determining their 

 true systematic position, were accidently omitted from their 

 proper places in the preceding parts. Altogether forty species 

 are included in this part, of which twelve are new to science. It 

 has been necessary to erect two new genera, Sigmaxinella and 

 Pseudoclathria. 



. This brings us to the end of the Monaxonida, at least according 

 to the acceptation of that term in the Challenger Report, but 

 there still remain a number of genera of doubtful position, whose 

 consideration I postpone until I shall have been able to study 

 more fully the Tetractinellid Sponges, with which they seem to 

 have more or less affinity. Such are the genera Tethea, Chondrilla, 

 Stelleitmopsis, Trachya, Halisarca and Chondrosia. 



At this stage of the work one cannot help being struck with 

 the exceeding richness of the monaxonid sponge-fauna of the 

 Victorian coast. The present catalogue includes altogether 135 

 species and no doubt many still remain to be discovered. 



Perhaps I may be allowed in this place to express my very 

 deep regret at the death of my old friend Mr. J. Bracebridge 

 Wilson, to whose untiring exertions the study of Spongology is 

 so deeply indebted, and whose loss leaves a gap in the list of 

 Australian Naturalists which we can scarcely hope to see rilled. 



