THE COTTON-WORM. 



359 



The larger moths are represented by the canker-worm, 

 the grass army- worm (Fig. 351), and the cotton army- worm 

 (Fig. 352), so destructive to 

 vegetation ; the silk - worm 

 moth (Bombyx mori Linn.), 

 of the Old World, and the 

 American silk- worm (Telea 

 Polyphemus Linn.). Certain 

 species of the silk - worm 

 family, called basket-worms 

 (CEceticus), live in cases con- 

 structed of short or long strips 

 (Fig. 353. Our native species 

 is Thyridopteryx ephemercefor- 

 mis Haworth. 



The hawk-moths (Sphinx) are distinguished by their 

 large size and very long tongue. The butterflies differ from 

 the moths in having knobbed anten- 

 nse, while the chrysalides are often 

 ornamented with golden or silvery 

 spots. 



Order 16. Hymenoptera. The bees . 

 stand at the head of the insect series 

 in perfection and specialization of 

 parts, especially the organs of the 

 mouth, and from the fact that in the 

 course of the metamorphosis from 

 the larva to the pupa the first ab- 

 dominal segments become transferred 

 to the thorax a striking instance of 

 the principle of transfer of parts 

 headward. In the large head, spheri- 

 cal thorax, and short, conical abdo- 

 men, the bees are opposed to the 

 dragon-flies and other Neuroptera, 

 in which the abdomen is long, the 

 thorax composed of three homogene- 

 ous segments, and the mouth-parts only adapted for biting. 

 In the bee there is a marked differentiation of the parts of 



