80 KENIEEA. — HALICHONDEIA. 



inillim. thick aucl 0-19 millim. long. The connecting spicules are similar. 

 Besides these, more slender spicules of a similar kind also occur. 



Geographical Distribution. — East coast of Australia : Port Jackson, 

 N. S. "W. (Bamsaif). 



Genus PETROSIA. 



Hard sponges, the skeleton of which consists of a dense network 

 of thick spicule-bundles. 



Petrosia hebesj u. sp. 



Irregular, massive sponges, horizontally extended, 80 millim. broad and 

 30 millim. higli ; with digitate processes on the upper surface, which attain 

 a length of 40 millim. and a thickness of 15 millim. ; they are irregularly 

 curved, knotty, and often flattened. The surface is smooth. Oscula incon- 

 spicuous and scattered, circular, 1-3 millim. in diameter. 



Sl-eleton composed of a network of very thick (0-2 millim.) fibres, with 0*5 

 millim. wide meshes; the fibres are composed of stout and large oxvstrongylote 

 spicules with blunt ends, which measure 0-22 millim. in length and 0-013 

 millim. in thickness. Similar spicules are scattered abundantly throughout 

 the ground-substance. 



Geographical Distribittion. — East coast of Australia : Port Jackson, 



N. 8.W.{Lendenfeld). 



Genus HALICHONDEIA. 



The skeleton consists of an irregular network of fibres, com- 

 posed of long and slender spicules. 



This genus is here accepted in the sense of Eidley and Dendy. 



Halichondria rubra, n. sp. 



Large sponges, with digitate, conical protuberances, which terminate in 

 rather sharp points ; the branches are 20-30 millim. thick. The whole sponge 

 attains a height of 300 millim. The surface is smooth ; the oscula are scattered 

 and of varying size, 2-5 millim. in diameter. In the living state the sponge is 

 of a bright scarlet colour, which is sometimes retained by spirit-specimens. 



The sl-eleton consists of a network with distinct main and counectiug fibres* 

 The main fibres, which extend longitudinally, are 0*15 millim. thick, and the 

 connecting fibres, which are vertical to the former, have an average diameter 



