Besides the bath-sponge, the Aquarium contains many spe- 

 cimens of sponges , which attract attention by their vivid 

 colours and various shapes. We will specially mention the splen- 

 did orange-red bunches of the Axinella and Myxilla, the cups 

 of the Reniera calyx, the sulphur-yellow balls of the Tethya, 

 and the branching coral-like colonies of the Clathria. 



The calcareous sponges are usually small and unsightly; the 

 largest species found in the gulf is the Leucandra aspe- 

 ra, with white pipe-shaped individuals united on one stock. 



One of the many advantages of the Aquarium of the Zoologi- 

 cal Station is that of being able to introduce to its visitors 

 living sponges. Their surroundings in the Aquarium so nearly 

 resemble natural conditions, that not only is it possible to tran- 

 sport the living sponges thither from the sea, but, during the 

 course of years, various species have settled on the rocky sides 

 of the tanks and nourish there to perfection , thus facilitating 

 their study to zoologists. 



Polypes (Anthozod). 



If it is strange to the uninitiated to hear animals called spon- 

 ges, which, w r hen seen alive, have nothing of a spongy appea- 

 rance, he will be no less astonished, when he learns that the 

 word coral means something else besides the beautiful red 

 or white branches which are often seen adorning a chimney- 

 piece or a writing-desk. And yet such branches are not the 

 real animals , but only the framework which they construct 

 for themselves, and in which they live side by side, or one over 

 the other, by hundreds and thousands. Of the real coral ani- 

 mal, scientifically called polype those polypes give the best idea 

 which are always the chief ornament of northern aquariums, the 



Actiniae or Sea-anemone*. 



In looking at these animals, we see a cylindrical column, the 

 base of which is fixed to some other object, and the upper end 

 of which is crowned with numerous and extremely mobile ten- 

 tacles. 



In the middle of this crown of tentacles there is an easily 

 recognisable opening , which is both the mouth and the anus 

 of the animal. This opening leads into a sort of wide sack, sur- 

 rounded by the muscular walls of the body, in which the food 

 is digested. At first sight it seems as if the soft naked body of 



