THE AQUAVIVARIUM. 



surface of the water, which 

 are one of the earliest har- 

 bingers of spring. 



Another order of Insects, 

 the Hemiptera, may be well 

 represented in the Aqua- 

 vivarium. Of these insects 

 we have two very common 

 well - marked forms, the 

 Water Scorpion (Nepal), 



Fig. 13, and the Water Boatmen (Notonecta), 

 Figs 16 and 17. Their movements form a pleasing 

 variety in contrast with those of other insects. 



FIG. 14. 



FIG. 15. 



FIG. 17. 



FIG. 16. 



The larvae of many of the 

 Hemiptera and Diptera in- 

 habit fresh water, and may 

 be kept till their last changes 

 are expected. In the spring, 

 the Caddice-worms (Fig. 18), 

 which inhabit little cases of 



most varied structure, may be collected, and their 

 habits watched. They are the larvae of various 

 species of Phryganea, and representatives of the 

 order Trichoptera. 



FIG. 18. 



