The Inhabitants of the Aquarium 301 



the color of its surroundings that it is rather 

 difficult to discover. Resembling so closely 

 the decaying or dead part of some aquatic 

 plant, the collector may discover it only 

 when it moves. It is found in ditches and 

 ponds everywhere. 



The Diving Water Spider (Argyroneta 

 aquatica) is one of the most interesting in- 

 habitants of our ponds, even if it may not 

 find a general introduction in the aquarium. 

 Anyone who has been out to collect material 

 for the aquarium must have observed a 

 gray-brown spider, not unlike one of our 

 common earth spiders, which, when brought 

 up in the net, makes violent efforts to escape, 

 appearing remarkably dry, considering that 

 it has just been fished out of the water. The 

 inexperienced collector or casual observer 

 may take the spider for the victim of an 

 accident and pay no further attention to it. 

 The better informed and older collector will 

 know at once that the prisoner is the Water 

 Spider and that its aim in leaving the net 



