222 CLATHEiA. — THALASSODENDEON. 



Clathria pyramida, n. sp. 



Massive sponges with rough surface, covered with regularly pyramidal pro- 

 cesses, attaining a maximum diameter of 150 millim., and attached by a broad 

 base. The living sponge is of a dark violet colour. 



The sl-eleton consists of fibres 0-09 millim. thick, which contain an axial 

 bundle 0*04 millim. thick, of slender straight styli 0*26 millim. long and 0*004 

 miUim. thick. They are echinated by leather scarce spined styli, which are 

 distributed in a more or less verticillate manner, 0*1 millim. long, and covered 

 with low spines, particularly in their basal portion, and there 0*008 millim. thick. 

 Abundant spicules of two kinds are scattered throughout the ground-sub- 

 stance : — (1) styli, similar to those in the fibres ; (2) chelae, 0-02 millim. long. 



GrEOGEAPHiCAL DiSTEiBUTiON. — East coast of Australia : Port Jackson, 

 N. S. W. {Ramsay). 



Clathria australis, n. sp. 



Plabelliform sponges with irregular, more or less circular outline. The 

 lateral margins are continuous, simply convex ; the upper margin is slightly 

 undulating. The two faces of the lamellar spo]]ge are covered by longitudinal, 

 radially disposed grooves which extend from the broad base of attachment to 

 the upper margin. In some specimens two or moi'e such lamellae are joined by 

 a transvei-se piece. The sponge attains a height of 150 millim., and the 

 lamella is 30 milhm. thick. 



The slceleton consists of a network of fibres, which can be distinguished into 

 main and connecting-fibres. The main fibres are entirely filled with spicules, 

 and on an average 0*] millim, thick. The connecting-fibres are 0*03 millim. 

 thick, and free from spicules. The spicules of the main fibres are straight 

 styli, 0-015 millim. long and 0"006 millim. thick. The main fibres are 

 echinated with scarce, spined styli, 0-1 millim. long and 0-007 millim. thick. 



Geogeaphical Disteibution. — South coast of Australia : Port Phillip, V. 

 {Lendenfeld). 



Genus THALASSODENDEON, n. gen. 



Desmacidonidse with a supporting skeleton composed of horny 

 fibres partly without spicules in the interior, and echinated by 

 scarce, pretty smooth styli. 



