244 



KEY TO THE AUSTEALIAN GENEKA. 



I "Without distinct horny fibre 



[ With distinct horny fibre 



Spicules singly form a network with triangular 

 meshes. Sponge soft, fragile 



Skeleton composed of a dense network of stout 

 spicule-bundles. Sponge hard 



37 V Skeleton composed of a loose network of 

 spicule-bundles. Sponge massive, soft. . . . 



Skeleton composed of a network of spicule- 

 bundles. Amount of spougin comparatively 

 great. Sponge thin, lamellar, fiower-shaped, 

 and pretty elastic 



'Sponges massive, irregular. Fibres thin. 

 Spicules slender 



Hard, irregularly digitate or lamellar sponges, 

 with very thick fibres 



Frondose sponges with narrow meshes of the 

 skeleton-net 



Tubular or cup-shaped sponges with slender 

 spicules 



(38) < 



39 



46 



Massive or digitate sponges with large 

 obliquely situated and partly protruding 

 spicules 



Sponges with solid, slender, cylindrical, regular 

 digitate processes. Spicules slender and 

 numerous. Main aud connecting- fibres 

 well defined 



Digitate sponges with foreign bodies in the 

 main and proper spicules in the connecting- 

 V- fibres 



(Spicules abundant 

 Spicules scarce 



f Sponge massive, meshes of the skeleton-net 

 wide 

 ^ Sponge lobose ^ 



37 

 (38) 



Reniera, p. 77. 

 Petrosia, p. 80. 

 Halichondria, p. 80. 



Reniochalina, p. 82. 



39 



(40), p. 245. 



(41), p. 245. 



(42), p. 245. 



(43), p. 245. 



(44), p. 245. 



(45), p. 245. 



46 



(47), p. 245. 



Cacochalina, p. 83. 



48 



