2 



Genus ASCETTA. 



Asconidae with predominant triact spicules, some of which may 

 possess an incipient fourth ray ; without diacts. 



Ascetta procumbens, Lendenfeld. 



Ascetta proeumbens, E. von Lendeufeld, " A Monograph of the Australian 

 Sponges. — Part III.," Proceedings of the Linnean Society of New South 

 Wales, vol. ix. part 4, p. 1086 (1885). 



The sponge consists of numerous slightly curved cylindrical tubes, which 

 chiefly extend in one plane, anastomose to form perforated plates, and attain a 

 diameter of 25 and a thickness of 2-5 millim. 



The skeleton is regular. The i*ays of the spicules are 0*1 millim. long and 

 at the base 0-015 millim. thick ; they are pretty stout, conic, and slightly rounded 

 at the ends. Our species is distinguished from the allied species by the rays of 

 its spicules being neither cylindrical as in Ascetta coriacea nor pointed as in the 

 numerous varieties of Ascetta primorcUalis ; besides that, the spicules are shorter 

 than those of the latter and thicker than those of the former. 



Geographical Distkibution. — South coast of Australia : Port Phillip 

 {Lendenfeld). East coast of Australia : Port Jackson {Lendenfeld). 



2. Ordo HETEROCCELA. 



Calcarea with differentiated entoderm. The ciHated chambers 

 are clothed with collar-cells and the gastral cavity with entodermal 

 pavement-cells. 



I adopt Polejaeff's name, with a different definition but nearly identical 

 meaning. 



FamiUa SYCONID^. 



Heterocoela with cylindrical ciliated chambers which traverse 

 the body-wall, are situated radially and open direct into the 

 gastral cavity. Sensitive cells around the inhalant pores. 



Identical with Eaeckel's Sycones. 



Connected with the Asconidse by Homoderma and with the Leuconida) by 

 Vosmaeria. 



