CHAP. XIII. FAMILIES OP LEPIDOPTERA. 



75 



usually prismatic and spindle-shaped, and are sometimes 

 hooked at the tip. 



Fig. 195. 



These moths fly mostly in the evening twilight; their flight 

 is strong and rapid, and they may frequently be seen hovering 

 over flowers, like humming birds. 



Their caterpillars are naked and provided with sixteen legs, 

 and sometimes have a spine or horn on the eleventh segment; 

 they live exposed upon the leaves of plants. When about to 



