tHORIOSPONGIA. 193 



Phoriospongia levis, n. sp. 



Large irregular or lamelliform, short and stout sponges, with digitate pro- 

 cesses, which attain a height of 120 millim. and a thickness of 12 millim. The 

 surface is roughened by the projection of short, stout, cylindrical, terminally 

 rounded conuli. Circular pseudoscula, about 7 millim. wide, are found in a 

 row on the margin of the frondose and on the summits of the processes of the 

 digitate forms. The lacunose spaces in the intervals of the reticulation of the 

 more solid sponge-tissue are circular canals, on an average 2 millim. wide, 

 pervaded by fine membranes. The sponge is in all conditions sand-grey. 

 Dry specimens are soft and friable. When alive the sponge is pretty tough 

 and slightly elastic. 



The skeleton consists of a rather irregular reticulation of fibres O'Ol millim. 

 thick. In the body of the sponge, but not in the membranes pervading the 

 vestibular lacunse, roundish sand-grains, 0*2-0"3 millim. in size, are scattered. 

 These are on an average 0*5 millim. apart, surrounded by a layer of spongin, 

 and attached to each other by the fibres of the skeleton-net. Siliceous spicules 

 of two kinds are scattered throughout the sponge. These spicules are not in 

 connection with the supporting skeleton-net. The spicules are («) strongyla, 

 0-1 millim. long and 0-0012 millim. thick, and (6) curved sigmata, which are 

 very slender and 0-03 millim. long. 



GrEO&BAPHiCAL DISTRIBUTION. — East coast of Australia: Port Jackson, 

 N. S. W. {Ramsay). 



Phoriospongia reticulum, Marshall. 



Phoriospongia reticulum,'W . Marshall, "UeberDysideiden und Phoriospongien," 

 Zeitschrift fiir wissenschaftliche Zoologie, Band xxxv. Seite 124 (1880). 



Massive, horizontally extending, cake-shaped sponges, with irregular or 

 polygonal depressions on the surface between a reticulation of curved and 

 irregularly anastomosing ridges. The oscula are 1*5-4 millim. wide, and scat- 

 tered or arranged in rows in the circumference of the upper surface. Dry 

 skeletons are soft and friable. 



The sJceleton consists of an irregular network of tortuous bands, 0"6-l 

 millim. broad, composed of loosely scattered sand-grains, which do not appear 

 to be at all connected with each other. The sand-grains are on an average 

 0-2 millim. broad and about equally far apart. The meshes between these 

 bands of sand-grains are 1-3 millim. wide. In the surface a layer, 0*5 millim. 

 thick, of similar isolated sand-grains is observed. Spicules are very abundant 

 in the ground-substance ; these are sigmata, 0*05 millim. long, and uniformly 

 scattered throughout the whole of the sponge. According to Marshall, styli 

 and tylostyli are present. The inhalant pores are confined to the depressions 



o 



