534 A MONOGRAPH OF THE AUSTRALIAN SPONGES, 



The excessive hardness of this variety is due to the exceptional 

 thickness of the main fibres. 



Histology. 



The histology of some of the Mediterranean varieties has been 

 worked out in such a manner by P. E. Schulze (I.e.) that it would 

 be necessary to translate them verbatim here. As however every 

 one, who intends to study the sponges must ij)se facta possess and 

 read F. E. Schulze's works, it will suffice here simply to refer to the 

 work of that author cited above. 



Geographical Distribution. 



Mediterranean, (compare particularly Eckhel's map) ; North 

 Atlantic Ocean, (Eckhel, Hyatt and others) ; South Atlantic 

 Ocean, (Ridley) ; North Pacific Ocean, (Carter and Hyatt) ; 

 Indian Ocean, (Pallas). 



In the Australian Seas. 



I. EUSPONGIA officinalis CAVERNOSA. 



North Coast of Australia, Torres Straits. (Alert.) 



II. EuSPONGIA officinalis DURA. 



West Coast of Australia (Bailey) ; South Coast of Australia, 

 Port Phillip (Hyatt). 



Bathymetrical Distribution. 

 20-200 metres, in the Mediterranean (Eckhel). 



I. EuSPONGIA officinalis CAVERNOSA. 



19 metres, 



II. EuSPONGIA officinalis DURA. 



Shallow water. 



