BY R. VON LENDENFELD, PH.D. 19 



The flat extended Sponge measures, full grown, 70 ram., in 

 length, and 40 mm., in width. It is the largest of the Australian 

 Gumminse I have seen. The plate is of uniform thickness 

 throughout measuring from 10-12 mm. 



The outer surface is smooth. The whole Sponge has a light 

 brown colour. The oscula are few in number, about seveii to a 

 large specimen, circular and slightly drawn in, that is to say at the 

 bottom of slight funnel-shaped depressions in the surface, and 

 surrounded by a ring-shaped slight elevation. Sometimes they lie 

 in the plane of the surface. 



The interior of the Sponge is coloured a little darker than the 

 Cortex. A transverse section shows that the canals in the pulpa 

 are more numerous and smaller than in other species. 



The structure of the inner parts afford no peculiarity. The 

 Cortex, however, is of great interest. 



There are two kinds of spicules in this species as in the foregoing 

 one. Spherical and stellate ones. 



The spherical sjncule measures 0"015 mm. across ; the spines are 

 particularly short, broad, conic and truncate, with very sharp points 

 they measure O-QOl mm. in height and are at the base 0-0015 mm. 

 thick. 



The stellate spicule measurea 0-01 across; the spines are mostly 

 smooth and generally taper to one fine and sharp point, they are 

 slender and conic, measuring 0-004: nun. in length and at the base 

 0008 mm. in width. 



In the pulpa we find both kinds of spicules distributed pretty 

 evenly with a slight preponderance of the stellate spicules. The 

 spicules are scarce and on thin sections very far apart. 



In the outer part of the Cortex, ^ust below the outer surface we 

 meet with a regular hard pavement of the spherical spicules which 

 lie closely packed in three or four layers above one another. They 

 lie as close to one another as their spherical shape will allow, and 

 their spines are interposed with one another in such a manner 



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