ACTION or THE CARNIVOEOUS WATEK-BEETLEa. 



173 



9.39 to breathe for 17 seconds. 



15 



4 



12 



12 



5 



15 



Observation ceased at 10.11 p.m. 

 During this hour the insect was in constant activity, and glided 

 about in the water in a graceful manner, generally rather slowly, 

 and with a motion similar to that of Hydrovatus, the four front 

 legs being used in paddling, probably in combination with the hind 

 tarsi or the hind tibiae and tarsi, the femora being probably flexed 

 and quiet ; it can, on being alarmed, shoot away with great velocity, 

 this probably being accomplished by the use of the hind leg in its 

 entirety. 



No. 3. Oct. 17th, 1875. — Observations commenced at 2.1 p.m., 

 beetle not having been fed for two days ; beetle buried in mud ; 

 rose at 2.13 for 5 seconds to breathe, and again at 2.55 for 5 

 seconds. Observation ceased at 3.4 p.m., beetle fed at 3.6. 

 No. 4. Observation resumed at 4.25 ; beetle rose at 



3 seconds to breathe. 



1 second to breathe. 



5 (?) sees, to breathe. 



1 second to breathe. 



Observation ceased at 5.25. 



No. 5. Later on observation recommenced at 9.7 p.m., by lamp- 

 light ; beetle appeared at 9.44 for 4 seconds to breathe. Obser- 

 vation ceased at 10.7. 



