520 A MONOGRAPH OF THR AUSTRALIAN SPONGES, 



0'42 mm., apart. Main fibres cored to some little distance from 

 surface by a usually single series of small foreign bodies ; connect- 

 ing fibres uncored. 



Rigidity. 



Textui-e of sponge in spirit very tough and elastic. 

 Geograhpical Distribution. 



North Coast of Australia, Torres Straits, Alert Island; (Alert.) 



Bathymetrical Distribution. 

 15 metres. 



III. SUB-GENUS. LAXIFIBRIS. 



The skeleton of this sub-genus is very remarkable and shows, as 

 indicated above, a further developement of the skeleton of Euspongia 

 canaliculata dura. 



The main fibres resemble those of Hircinia in as much as they 

 are formed of a trellis work of densely interwoven fibres. The 

 longitudinal ones are thicker than the transverse ones and one or 

 two are particularly well developed and contain foreign bodies. 



The connecting fibres are differentiated into primary and 

 secundary fibres. 



The primaries are not ramified, long smooth and gracefully 

 curved. They are never bent at the joining points. 



The secundaries are very short and thin, always simple and 

 straight, and connect the primaries, both are free from foreign 

 bodies. 



72. SPECIES. EUSPONGIA MATHEWSI. Von Lendenfekl. 



COSCINODERMA LANUGINOSUM. Carter (1). 

 COSCINODERMA LANUGINOSUM. Carter (2). 



In the discussion of the varieties of Euspongia conaliculata I 

 have given the reason for not considering peculiarities in the 



(1) //. /. Carter. Contribution to our Knowledge of the Spongida. 

 Annales and Magazine of Natural History. 5th Series, Vol. XII., No. 71, 

 p. 309. 



(2) //. J. Carter. Descriptions of Sponges from the neighbourhood of 

 Port Phillip Heads, South Australia. Annales and Magazine of Natural 

 History, 5th Series, Vol. XV., No. 88, p. 318. 



