140 



HALF HOURS WITH INSECTS. [Packard. 



side along the tunnel under the hairs and collects in bubbles 

 above the base of the legs. Along the bottom of this 



Fig. 102. 



Hydrophilus piceus, eggs and larva. 



tunnel are six pairs of spiracles into which the air passes. 



The air in the specimens we observed did not adhere to the 

 hairs of the hind legs as Siebold says it does, nor, 

 as he states in his "Comparative Anatomy," trans- 

 lated by Burnett, does the air for respiration as a 

 rule pass under the elytra, since the spiracles arc 

 not situated on the upper side of the body but on 

 the under, and quite a distance from the edge of 

 the body. Nor does this insect breathe at all, as 

 Westwood states, like Dytiscus, in which the spir- 

 acles are situated on the upper side of the body, so 



that the air enters readily under the elytra. When it takes 



in the air the tip of the abdomen is thrust up just above 



12 



Notonecta. 



