218 CLATHEISSA. 



thickened proximal end 0-009 millini. thick, which stand very steep, often nearly 

 perpendicular. 



Geogeaphical Disteibution. — East coast of Australia : Port Jackson, 



Clathrissa elegans, n. sp. 



Tree-shaped branched sponges of large size and elegant shape, consisting of 

 a short vertical stem about 15 millim. thick, from which numerous more 

 slender branches grow out. These tend upwards and are curved in such a 

 manner as to become perpendicular in their distal portions. Fresh sponges 

 of this species are soft and resilient. Alive, in spirit, and dry it is dark brown 

 in colour. 



The skeleton consists of a network of spicule-bundles 0*027 millim. thick, 

 and on an average 0-025 millim. apart. These consist of densely packed 

 straight oxea 0-2 millim. long and 0-004 millim. thick; some of them attain a 

 much larger size. Occasionally styli are observed. The fibres are echinated 

 by spined styli, which are more numerous towards the surface than in the 

 interior. These styli are on an average 0-09 millim. long and 0*06 millim. 

 thick. 



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

 N. S. W. (Ramsay, Lendenfeld). 



Clathrissa pumila, n. sp. 



Small, incrusting, conulated sponges, of a light rose-colour in the fresh state 

 and grey when preserved in spirit. The conuli are on an average 2 millim. 

 high and 4 millim. apart. Small oscula 0-8 millim. wide are scattered irre- 

 gularly over the surface. 



The sheleton consists of perpendicular fibres 0-09 millim. thick, which ter- 

 minate in the conuli. They are composed of styli and oxea, cemented by a 

 small quantity of spongin. The ends of the spicules often protrude beyond 

 the surface of the fibre. They measure on an average 0-2 millim. in length 

 and 0-005 millim. in thickness. These fibres are echinated by densely packed 

 perpendicularly situated, spined styli, which are on an average 0*11 miUim. 

 long, and at the base 0-007 millim. thick. The chelae scattered in the ground- 

 substance are very abundant, 0'012 millim. long. Besides these there ai*e also 

 spicules similar to those in the fibres, scattered in the ground-substance. 



G-EOGEAPHiCAL DiSTEiBUTiON. — East coast of Australia : Port Jackson 

 N. S. W. (Bamsay, Lendenfeld). 



