THE DRAWING OF THE SEINE. 181 



thirsty name, so water-tiger let it be ; although I have 

 caught the habit of my entomological acquaintances, 

 and speak of it generally, to them at least, as the Dytis- 

 cus. There was one of these beetles in the mass of 

 weeds. It did not bite me when I picked it up, but it 

 had jaws that could have brought my blood if the creat- 

 ure had been disposed to try. 



Happily, these large beetles are not very abundant, or 

 small fish would have a hard time of it. Tliey are quick 

 as a flash, and seize a fish just as the little water-boat- 

 men do, and, once seized, there is no hope of escape. 



Dr. Packard considers the cylindrical larva of this bee- 

 tle as voracious as an insect can be, remarking of them 

 that their " large fiattened heads, armed with scissor- 

 like jaws with which they seize other insects," are also 

 used to " snip off the tails of tadpoles," and they " are 

 even known to attack young fishes, sucking their blood." 



This is unquestionably true of these larval water- 

 tigers. I took a half-dozen of them, some summers 

 ago, from Poaetquissings, and placed them in an aqua- 

 rium, where were several choice specimens of small 

 fishes brought from a distance. During the day all 

 went well, but next morning I found they had attacked 

 the fishes and worried them to death. If, therefore, 

 aquatic beetles are wanted in an aquarium, let them not 

 be associated with small fishes, if you value the latter. 



This, of course, does not close the list of water in- 

 sects; but what else will be found will prove closely 

 related to those that I gathered from the weeds after 

 the drawing of the seine. 



Some of these insects, as has been mentioned, prey 



