ARTHROPODA. 



301 



.colors, and are often arranged in patterns of exquisite 

 beauty. They are in reality modified hairs, and every 

 family has its partic- 

 ular form of scale. 

 The head is small, 

 and the body cylin- 

 drical. The legs are 

 not used for locomo- 

 tion. All the mouth 

 parts are nearly obso- 

 lete except the maxil- 

 lae, which are fash- 

 ioned into a " probos- 

 cis " for pumping UP Fig. 272. —Part of the Wing of a Moth (Saturnia), 

 r r 5 r magnified to show the arrangement of scales. 



the nectar of flowers. 



The larvae, called caterpillars," have a worm-like form, 

 and from one to five pairs of abdominal legs, in addition 

 to the three on the thorax. The mouth is formed for mas- 

 tication, and (ex- 

 cept in the larvae 

 of Butterflies) the 

 lip has a spinneret 

 connected with silk- 

 glands. 



There are three 

 groups : the gay 

 Butterflies, having 

 knobbed or hooked 

 antennae, and flying 

 in the day only ; 

 the dull-colored Sphinges, with antennae thickened in the 

 middle, and flying at twilight ; and the nocturnal Moths, 

 which generally prefer the night, and whose antennae are 

 thread-like and often feathery. Generally, when at rest, 

 the Butterflies keep their wings raised vertically, while 



Fig. 2T3. — Vanessa polycldoros, or "Tortoise-shell But- 

 terfly." 



