BY R. VON LENDENFELD, PH.D. 847 



It is very remarkable that silicious spicules are found in great 

 abundance in this sponge. Near the skin the main fibres form 

 branches in a penicillate manner, and the branches are constituted 

 nearly exclusively of spicules, which vary much in shape and 

 size, but still I think it not unlikely that this sponge may 

 belong to the silicious sponges, and that the spicules are not 

 foreign bodies as I assume. The spicules in the surface are 

 mostly slender and long, averaging 0.2 mm. in length and 

 0.003 mm. in thickness. In the interior numerous short and 

 stout spicules are found together with slender ones such as those 

 on the surface. These are Tr. Ac, and measure 0.08 x 0.007 mm., 

 and are often inserted into the horny fibx^es as in the true 

 Echispidse. This species is one of those forms which, like certain 

 species of Dactylochalina and Chalinopsis, are intermediate, 

 between the horny and the silicious sponges. 



I. Variety, Halme laxa minima. 



Small a^d irregular, the digitate processes hardly longer than 

 high, and the whole sponge flat and extended, more or less 

 incrusting. The network of the sponge lamella is formed of 

 lamellae not more than 1 mm. thick, whilst the meshes barely 

 exceed a width of 10 mm. 



Geographical Distribution. 

 East Coast of Australia, Port Jackson, (von Lendenfeld.) 



Bathymetrical Distribution, 

 30 metres. 



II. Variety, Halme laxa digitata. 



Grows to a large size, the digitate processes attaining a height 

 of 300 mm., by a width of 70 mm. They are however, not so 

 numerous as in the foregoing variety. The meshes of the network 

 are much wider, averaging a diameter of 20 mm. 



