SPONGILLA. — TUBELLA. 75 



Spongilla sceptroides, Haswell. 



Spongilla sce]itroides,'W . A. Haswell, "On Australian Freshwater Sponges," Pro- 

 ceedings of the Linnean Society of New South Wales, vol. vii. p. 209 (1883). 



Sjjongilla sceptroides, R. v. Lendenfeld, "Die Siisswasser-Coelenteraten Aus- 

 traliens," Zoologische Jahrbiicher (Spengel), Band ii. Seite 89 (1887). 



Sponge green, incrusting, smooth, pretty elastic, not crumbling. Skeleton- 

 spicules suiall, curved, spindle-shaped, sharply pointed at each end, with small 

 spines. Statoblast round, enclosed by slender, long, straight, cylindrical 

 spicules, with long pointed thorns ; the thorns accumulate towards the ends, 

 where they form distinct swellings : the central part of the spicule has no 

 thorns. 



I add to this description of Haswell's (I. c.) that the skeleton-spicules are 

 cylindrical and abruptly pointed, and measm*e on an average 0-25 millim. in 

 length and 0-01 millim. in thickness. The specimen seen by me is a branch 

 8 millim. thick and 20 millim. long. 



Geogeaphical Distribution. — Near Brisbane, Queensland (Haswell), 



Genus TUBELLA. 



The gemmule-capsule consists of a layer of radially disposed 

 ampliidiscs ; the terminal discs of unequal size (inaequibirotulate). 



Tubella nigra, Lendenfeld. 

 Tuiella nigra, E. v. Lendenfeld, " Die Siisswasser-Coelenteraten Australiens," 

 Zoologische Jahrbiicher (Spengel), Bd. ii. Seite 91 (1887). 



Sponge incrusting, black ; the crusts are 3-5 millim. thick, the surface is 

 continuous and appears velvet-like. The sponge extends horizontally, and 

 attains a length of 70 millim. and a breadth of 50 millim.; the outline is irre- 

 gular, lobose. The sponge is soft ; the spicule-bundles which form the fibres 

 of the skeleton are very slender, often composed of a single row of spicules. 

 The canals are narrow and insignificant. The gemmules form a continuous 

 layer at the base of the sponge. 



The sTceleton-spicides are spindle-shaped and gradually pointed ; their average 

 length is 0-22 millim., and the central part measures 0-0074 inillim. in thick- 

 ness. They are sharply pointed, entirely smooth, and slightly curved. The 

 gemmules are irregularly globular and measure 0-3 millim. in diameter ; the 

 umbilical depression is well pronounced. The amphidiscs are 0-033 miUim. 

 long ; the slender stalk, which bears a few sharp and slender spines, is 0-0015 

 millim. thick ; the spines sometimes attain a length equal to the radius of the 



