BY R. VON LENDENFELD, PH.D. 



499 



the interior of the sponge, but otherwise it appears quite con- 

 tinous. There can be no doubt, that by contractions of this 

 membrane the width of the sub-dermal cavity can be decreased, 

 and by local contractions the water current regulated. 



Subgenus Densalis. Subgenus Silicatis. Subgenus Ditela. Subgenus Laxifibris. 



Subgenus Regularis. 



Subgenus Triplicis. 



Euspongia irregularis, Euspongia irregularis silicata. Euspongia irregularis 

 lutea, siliceous spicules predominate tenuis, indication of 



fibres being equalised. in main fibres. differentiation into 



Primaries and Secun- 

 daries. 



Euspongia irregularis. 



Jacksonia irregular. 



Geographical Distribution. 



I. Euspongia irregularis silicata. 



South Coast of Australia, St. Vincent Gulf (Haacke) ; East 

 Coast of Australia, Port Jackson (Von Lendenfeld) ; Fiji 

 (Ramsay); Chatham Islands (Parker). 



II. Euspongia irregularis lutea. 

 Mauritius (Von Haast). 



III. Euspongia irregularis tenuis. 



North Coast of Australia, Torres Straits (Haacke) ; East Coast 

 of Australia, Long Reef (Ramsay) ; Chatham Islands (Parker) ; 

 Mauritius (Von Haast). 



