70 CHONDEILLA. 



the base, and regularly conic ; the surface of the central sphere is not visible 

 because the spines stand so close together that their bases are in contact. 



Geogeaphical Disteibtition. — South coast of Australia : Port Phillip, V. 

 {Lendenfeld). 



Chondrilla corticata, Lendenfeld. 



CliondriUa corticata, E. von Lendenfeld, " A Monograph of the Australian 

 Sponges, Part IV. — II. Ordo Myxospongia, Haecl-el" Proceedings of the 

 Linnean Society of New South Wales, vol. x. part ]., p. 154 (1885). 



This species is characterized by its extremely hard cortex. 

 It has only been found in the shape of rather thin lamellae, which are 

 peculiarly bent and curved, and often attain the shape of a cup. The flat, 

 extended sponge measures, when full-grown, 70 millim, in length and 40 

 millim. in width. It is the largest Australian CliondriUa I have seen. The 

 lamella is of uniform thickness throughout, measuring from 10-12 milhm. in 

 diameter. 



The outer surface is smooth. The whole sponge has a light brown colour. 

 The oscula are few in number, about seven to a large specimen ; they are 

 circular and slightly drawn in, that is to say, situated at the bottom of slight 

 funnel-shaped depressions in the surface, and surrounded by a slightly 

 elevated ring ; sometimes they lie in the plane of the surface. The interior 

 of the sponge is a little darker in colour than the cortex. The canals in the 

 pulpa are moi-e numerous and smaller than in other species. The structure 

 of the pulpa exhibits no peculiarity ; the cortex, however, is interesting. 



There are two kinds of spicules — spherical and stellate ones. The spherical 

 spicule measures 0*015 millim. .; the spines are particularly short, broad and 

 conic, and terminate in very sharp points ; they measure 0*001 millim. in 

 length and are at the base 0-0015 thick. The stellate spicule measures 0-01 

 millim. ; the spines are mostly smooth and generally taper to a fine and 

 sharp point ; they are slender and conic, measuring 0"004 millim. in length 

 and at the base 0*0008 millim. in thickness. In the pulpa we find both these 

 kinds of spicules pretty uniformly distributed, with a slight preponderance 

 of the stellate spicules ; here the spicules are, on the whole, scarce and 

 in tnin sections they appear very far apart. In the outer part of the cortex, 

 just below the outer surface, we meet with a regular hard pavement composed 

 of the spherical spicules, which lie closely packed in three or four layers above 

 one another ; they are situated as close together as their spherical shape will 

 allow, and their spines are interposed in suoh a manner that the pavement 

 which they form attains a high degree of firmness. Similar cortical layers are 



