CHALINOPSILLA. 109 



mentioned. The foreign spicule-fragments in these fibres are situated nearly 

 longitudinally ; at the joining-points, however, their position is very irregular. 

 The fibres of the surface-skeleton contain similar foreign bodies. 



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

 N. S. W. {LendenfcU). 



Chalinopsilla elegans, n. sp. 



The sponge is erect, much branched, and appears reticulate, in consequence 

 of the frequent anastomoses of the branches. It attains a height of 300 

 millim. The branches, which rise from a small base or from the upper end of 

 a very stout and short peduncle, are irregularly cylindrical. The surface is 

 uneven, undulating ; the oscula are scattered, rather scarce, prominent, circular, 

 2-5 millim. wide. The branches average 15 millim. in thickness; they are 

 terminally rounded off and, although in their main course erect, much and 

 irregularly bent. 



The dry skeleton is chestnut-brown and pretty hard, compressible between 

 the fingers to about half its thickness. 



The surface-sl-eleton consists of a simple network, in which primary and 

 connecting-fibres cannot be distinguished. 



The supporthuj-sheleton is composed of smooth main fibres and thin un- 

 branched connecting-fibres, which join adjacent main fibres, and are perpendi- 

 cular to them. The main fibres have an average thickness of 0*22 millim. and are 

 0-55 millim. apart ; the connecting-fibres are 0*07 millim. thick, and about as far 

 apart as the main fibres, so that a network with quadratic meshes is produced. 

 In all the fibres foreign bodies of small size are found ; these form a dense 

 axial column about two thirds as thick as the fibre in the centre. The super- 

 ficial portion of the fibre is free from foreign bodies. The building-material 

 used by this sponge consists of a variety of things, among which tetraxon 

 foreign spicules and sand-grains predominate. 



GEoaEAPHiCAL DiSTRiBUTioisr. — West coast of Australia : Western Australia 

 {Baily). 



Chalinopsilla arborea, n. sp. 



Very irregular dendritic sponges, with a more or less developed peduncle 

 and irregular lobose and short ramifications or slender digitate knotty and 

 irregular branches. 



The surface is undulating, uneven, but smooth. The oscula are always 

 scattered and prominent ; their size, however, is subject to great variations. 



