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Genus VI. GYR1NUS. 



GENERIC CHARACTER. 



Antenna cylindrical, club-shaped, stift^ and 

 shorter than the head. Maxilla horny, arch- 

 ed and pointed. Eyes four in number, two 

 on the upper, and two on the under side of 

 the head. 



General Observations. 



On the surface of stagnant marsh waters, on 

 lakes, and on ditches, we often see swimming, 

 or as it were running, certain small, black, and 

 shining insects, collected together in numbers, 

 and describing circles with astonishing rapi- 

 dity. These are Gyrini, which notwithstand- 

 ing the small space in which so many of them 

 move, and the celerity of their motion, are not 

 often seen to strike against each other. The 

 French, from their circular motion, call them 

 Tourniquet; the English, from their lucid sur- 

 face, Glimmer chaffer. This latter name is par- 

 ticularly applicable when the sun shines upon 

 them ; then they look like so many brilliant 



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