No. 488] 



489 



lar\a of Ac 



indicated in the diaur 

 pli^lied l>y xen .li-h 



zontally once or twice, and finally n>f lo the --iii tacc, lail uj)\\ 

 as just described. This species swims \cry rapidly. twi>tiii<i' 

 turning its long slender body like a snake. AVhen di-sturlx 



darts witli a peculiar indescribable motion of the whole body 

 away from tlie i>oint of disturbance. Sometimes it niak(\s just 

 one quick dodge, and sometimes it goes through a series of wrig- 

 gling movements so swiftly executed that the eye cannot follow 

 them. This dodging feat must be of great advantage in avoiding 



The larva of ITydroporu. i Fiir. 4^ has ouU a scanty <leN,>lop- 



