LEPIDOPTERA 739 



SUPERFAMILY PAPILIONOIDEA 



The Butterflies 



The butterflies differ from moths in that they have clubbed an- 

 tennas, fly only in the daytime (except some species in the tropics), 

 hold the wings erect above the back when at rest, and have no 

 frenulum. Some moths present one or more of these characteristics, 

 but no moth presents all of them. Butterflies can be distinguished 

 from skippers by the venation of the front wings, as indicated above 

 in the characterization of the Hesperioidea. 



Among the many works treating of American butterflies the two 

 following are especially useful for the classification of our species, 

 each of these works is illustrated by many full-page plates representing 

 the insects in their natural colors: "How to Know the Butterflies, A 

 Manual of the Butterflies of the Eastern United States" by J. H. 

 and A. B. Comstock ('04), and "The Butterfly Book, APopular Guide 

 to a Knowledge of the Butterflies of North America" by W. J. 

 Holland (193 1). 



The butterflies found in America north of Mexico represent five 

 families. Our representatives of these families can be separated by 

 the following table. 



A. Butterflies in which the cubitus is apparently four-branched; and in which 

 the anal area of the hind wings is more reduced than the anal area of the fore 

 wings, as in the fore wings there are always two anal veins, and usually all 

 three are at least partly preserved, while in the hind wings there is only a single 



anal vein. p. 740 Papilionid^ 



AA. Butterflies in which the cubitus is apparently three-branched; and in 

 which the anal area of the fore wings is more reduced than the anal area of the 

 hind wings, the former having a single anal vein and the latter two. 

 B. Palpi much longer than the thorax (Subfamily Libytheinas) . p. 766 



Nymphalid^ 



BB. Palpi not as long as the thorax. 



C. With only four well-developed legs in both sexes, the front legs being 

 much shorter than the others, and folded on the breast like a tippet; 

 radius of the fore wings five-branched. To determine the number of 

 branches of radius, count the two cubital and the three medial branches 

 first, the branches left between vein Mi and the Subcosta belong to radius, 

 p. 750 Nymphalid^e 



CC. With six well-developed legs in the females and with the fore legs of the 

 males more or less reduced, only slightly reduced except in the metal- 

 marks; radius of the fore wings (except in some orange-tips, p. 747) only 

 three or four branched. 



D. Vein Mi of the fore wings arising at or near the apex of the discal cell 

 (except in Feniseca, p. 772) . 

 E. Hind wings with the costa thickened out to the humeral angle 



(Fig. 978) and with a humeral vein. p. 767 Riodinid^ 



EE. Costa of hind wings not thickened at base; humeral vein absent. 



p. 768 LvC^NIDiE 



DD. Vein Mi of the fore wings united with a branch of radius for a 

 considerable distance beyond the apex of the discal cell (Fig. 952). 



p. 744 PlERID^ 



