18 THE CANADIAN ENTOMOLOGIST. 



It was about nightfall when I placed him in the aquarium, and I was 

 around early the next morning to see how he had fared in his new 

 quarters. Imagine my surprise to find him sitting complacently on a 

 stock oi Sagittarius devouring the largest fish in my collection, a beautiful 

 trout about three inches long, while all about his new quarters were 

 scattered the skins of many victims, including young frogs, tadpoles, fish, 

 snails and various other smaller fry. He had fared altogether too well, 

 much like a weasel in a henhouse, with a propensity to kill everything in 

 sight. At that rate he would very soon totally depopulate my aquarium, 

 so I removed him to less commodious and more sparsely populated 

 quarters, and confined him to a diet of tadpoles and froglings. He would 

 devour, dozens of them in twenty- four hours, and have his quarters fairly 

 stinking with their remains. 



He captured his prey as they swam near him by a sudden dart 

 forward. The powerful hooked front legs were thrown over the victim, 

 which was pinned fast more quickly than the eye could follow, and the 

 sharp, curved, horny-pointed proboscis was thrust into its quivering sides, 

 never to be withdrawn until the skin was a limp and flabby sack of lifeless 

 material perfectly depleted of all the nourishing liquids and elements 

 pertaining to the body in life. His habit was to lurk in the more secluded 

 and darkened places in the aquarium, backing up occasionally to the 

 surface for a breath of fresh air, and quite often I would see him, after 

 returning to his lurking place, raising and lowering the wing-sheaths as 

 though breathing, and beneath them could be seen a large bubble of air, 

 advancing and receding with the up and down motion of the wings, and 

 looking for all the world like molten shining silver. The spiracles are 

 quite prominent, and placed at the lower, extremity of the abdomen, as is 

 usual in water-beetles. 



Sometimes I would take him from the water, and then he would 

 " play possum " for from three to seven minutes, but when he did wake 

 up was full of life and action. If I caught him and held him securely, he 

 would, after a moment or two, eject a few drops of clear liquid from the 

 spiracles with such force that it often bespattered objects three and four 

 feet distant. 



Occasionally he would entertain me with a semi-subaqueous serenade. 

 He would come to the surface, where there was a thick mass of duck- 

 weed floating, extrude the spiracles, and make a soft chirping noise, not 

 wholly unlike a subdued cricket song. I puzzled over this a long time 



