CHAP. XIII. FAMILIES OF LEPIDOPTERA. 71 



of cocoon by fastening several leaves together with silken 

 threads, and lining the interior with a thin layer of silk. 



The chrysalids of this latter class are usually smooth and 

 cylindrical, but taper posteriorly; the others are angular and 

 more or less tuberculate. 



CLASS II. MOTHS (Heterocera) . In these insects the anten- 

 nae never terminate in a knob, although it is frequently thick- 

 ened towards the tip. 



These insects usually fly about only at night or in the eve- 

 ning; their colors are generally dull, mostly of some shade of 

 gray, and the hind wings are seldom colored as brightly as 

 the fore wings, being commonly of a dirty-white or smoky 

 color. When at rest the wings usually cover the back like a 

 steep roof, the fore wings concealing the hind ones. 



Fig. 190 



A very few of the Caterpillars (such as those of the Plume- 

 moths) suspend themselves when about to change to a pupa; 

 but the greater number either spin cocoons, or enter the earth 

 and form smooth cells in which to undergo their transfor- 

 mations. 



CLASS I. BUTTERFLIES. (Rhopalotera.) 



These insects are divided into five Families, as follows: 

 SWALLOW-TAILS (Papilionidas). These Butterflies have the 



