DY R. VON LENDENFELD, PH.D. 317 



The membranes are covered on either surface by a flat 

 Ectodermal Epithelium. (Plate XXXIV., fig. 23, d.) In the 

 ground substance spindle-shaped cells are found which traverse 

 the membi-anes in all directions, (c) I do not doubt that some 

 of the fibres originating from the ganglia cells are connected with 

 those elements which I consider as muscle cells. 



By the sensitive cells the conditions of the water around them is 

 felt and an irritation transmitted to the ganglia cells below. There a 

 decision is arrived at, what should be done, provided these outer 

 conditions and with them the nervous irritation change. The 

 ganglia cells irritate the muscles, and so the pores in the 

 membranes can be dilated or contracted, and the current of water 

 changed and regulated with advantage to the sponge. Whether 

 any consciousness is connected with this process or not is hard to 

 decide. The whole process certainly has the appearance of a very 

 simple reflex action, so that a consciousness, in the human sense 

 can hardly be assumed. 



Geographical Distribution. 



East Coast of Australia, Port Jackson. (Ramsay, von Len- 



denfeld.) 



Bathymetrical Distribution. 



10-40 meti-es. 



The specimens from greater depth appear to possess longer villi 

 and a more massive shape, those from shallow water are more 

 flattened and more smooth. 



As the sponge, however, appears to be rare I am not able to 

 establish any bathymetrical varieties from the observations at my 

 disposal. Nardorus and Auloplegma forms have been dredged 

 from all these depths. 



Varieties. 



There are, as mentioned above no great varieties in the shape of 

 this sponge. Some possess Pseudoscula as described, whilst others 

 are Aulaplegmaforms. I propose to establish two varieties for 

 this species accordingly. 



