no INSECT LIFE. 



2. The head is inserted in the prothorax up to 

 the base of the eyes. The eyes, though small com- 

 pared with those of the dragon-fly, are really quite 

 large and prominent ; their shape and position are 

 such that the insect can readily see in all directions. 

 The antennas are long and consist of four segments. 

 The beak arises from the forward end of the head ; 

 when not in use it usually extends backward between 

 the fore legs. It consists of four segments ; the sec- 

 ond segment, however, is quite short and liable to 

 be overlooked. A bristlelike piercing organ can 

 usually be seen protruding from the tip of the beak. 

 Make a drawing of a side view of the head, show- 

 ing the form of the head, eyes, antennas, and 

 beak. 



3. Study the position and form of the legs. The 

 fore legs are placed well forward, and are stouter 

 than the others ; they are used for seizing and hold- 

 ing the prey. The middle and hind legs are placed 

 far back, and are the chief organs of locomotion, the 

 middle legs being used as oars and the hind legs as 

 rudders. A striking peculiarity of the legs in the two 

 families of water-striders is that the last segment of 

 the tarsus is split at the end and the claws are in- 

 serted in this cleft ; this is most easily seen in the 

 stouter fore legs than in the threadlike middle and 

 hind legs of the true water-striders. In the broad- 

 shouldered water-striders it is easily seen on any of 

 the legs. Make a drawing of the tarsus of one of the 

 legs, showing this peculiarity. 



4. Make a drawing of the lower side of the abdo- 

 men, noting carefully the form of the segments near 

 the caudal end. 



