44 



DRAGON-FLIES. EPHEMERAE. 



41. DRAGON-FLY. 



Fig. 42. 

 LARVA OF DRAGON-FLY. 



12. The Dragon-fies (f-gAl) Libel'lvla are remarkable 

 for their elongated form, their varied colours, their large, beautiful, 

 gauze-like wings, and their rapidity of flight. Their larvae and 

 nymphce (fig. 42) live in the water until the period of their last 

 transformation. In the two first states they resemble the perfect 

 insect, except that they have no wings, and the head, yet unpro- 

 vided with simple eyes, has a mark in front covering the mandi- 

 bles, which is furnished with movable pincers, by means of 

 which the animal seizes its prey. At the posterior extremity of 

 the abdomen (fig. 42) we remark lamellar appendages which the 

 larva constantly expands, while at the same moment it dilates the 

 rectum to cause water to enter it ; then it forcibly expels the 

 water mingled with bubbles of air, both for the purpose of loco- 

 motion and breathing. 



Fig. 43. EPHEMERA. 



13. The Ephemera (Jig. 43) have a very soft body terminated 

 by two or three long setae or filaments. As their name indicates, 

 these insects live but a very short time ; they usually appear in 



12. What are the characters of Dragon-flies? How do their larvse differ 

 from the perfect insect ? 



13. What are the characters of Ephemerae ? What are their habitt 

 flow does the larva differ from the perfect insect ? 



