THE NYMPHS 



The larvae are nearly or quite cylindrical, and are clothed 

 to a greater or less extent with hairs and sometimes with 

 branching spines. 



The chrysalids are usually angular, and often bear large 

 projecting prominences ; sometimes they are rounded. They 

 always hang head downward, supported only by the tail, 

 which is fastened to a button of silk. (Plate II, Fig. 2.) 



This is the largest of the families of butterflies. It not only 

 surpasses the other families in number of species, but it con- 

 tains a greater number and variety of striking forms, and also 

 a larger proportion of the species of butterflies familiar to 

 every observer of insects. There may be in any locality one 

 or two species of yellows or of whites more abundant, but the 

 larger number of species commonly observed are nymphs. 



In order to facilitate the study of the family our genera 

 have been separated into five groups, which are known re- 

 spectively as the Fritillaries, the Crescent-spots, the Angle- 

 wings, the Sovereigns, and the Emperors. 



The structural features distinguishing these groups are in 

 some cases difficult to observe, and consequently are not 

 available here ; but by means of the following somewhat 

 artificial table, our Eastern species can be placed in their 

 proper groups : 



A. Eyes hairy, p. 131. The Angle-wings (in part). 



AA. Eyes naked. 



B. Club of the antennae long and slender, increasing in 

 size gradually, as a rule hardly more than twice as broad 

 as the stalk. 



C. Hind wings with tail-like prolongations (the Goat- 

 weed Butterfly), p. 173. The Emperors (in part). 

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