532 a monograph op the australian sponges, 



Colour. 



The colour of the varieties hitherto examined in the live state, 

 varies according to F. E. Schulze (I.e.), from bright straw-yellow 

 to rust-red and dirty dark brown. The skeletons have the colour 

 of " burnt siena"* 



Surface. 



The surface differs according to variety and locality, conuli are 

 always present and scattered pretty regularly over the surface. No 

 conuli are found in close proximity to the oscula (indication of an 

 askeletous part as in Utispongia canaliculata, described above). 

 The conuli attain a height of 1 mm., and are of a similar thickness 

 at the base. In the fields between them, there is a very dense 

 network in the interstices of which the pore-sieves are found. 

 The pores are not numerous. The oscula are never raised and 

 scattered irregularly or else situated in lines. (Compare F. E. 

 Schulze's exhaustive description and his excellent figures, I.e.) 



There are very few foreign bodies in the skin. 



Canal System. 



The skin is pretty thick and there are very slender canals, which 

 lead from the inhalent pores into the subdermal cavities. The 

 latter consist of irregular cylindrical and tangental canals which 

 are not very wide, and separated by broad masses of tissue (F. E. 

 Schulze, I.e., Tafel XXXVI., fig. 2). 



The final ramifications of the inhalent canal system are narrow 

 and give off comparative wide special canals to the ciliated chambers 

 {F. E. Schulze, I.e., Tafel XXXVL, fig. 12.) 



The chambers open direct into the exhalents or ai'e connected 

 with them by short and narrow special canals hardly wider than 

 those which lead from the inhalents to the chamber pores. 



The exhalents join to form oscular tubes in the usual manner. 



In the variety Etts})ongia officinalis cavernosa, there are according 

 to Ridley (I.e.), very extensive lacunae. These are connected with 

 the apertures at the summits of the tubes. As Ridley's specimen 



