COMPARED WITH THOSE OF EUROPE. 625 



paler, often subnacrcous lunules, one of which in the upper median inter- 

 space is usually larger than the rest. 



Our North American species are generally double brooded or poly- 

 goneutic, and hibernate as half grown caterpillars. All the species, prob- 

 ably, arc dinior[)hic, the spring differing from the later broods. The eggs 

 are laid in clusters and those of one species hatch in from four to ten 

 days, according to season and locality. The species are generally abund- 

 ant in individuals and the caterpillars social. So far as known those of 

 most of the species make no web, but ^Ir. Henry Edwards states that in 

 the Californian P. pulchella (Boisd.) "the caterpillars spin a small web, 

 and draw the leaves of the plant together." The caterpillars feed upon 

 Compositae and Carduus. The butterflies delight in open, sunny spots, 

 their flight is slow and floating, but tremulous before alighting. They 

 rarely rise more than three or four feet above the ground, and frequent- 

 ly alight upon low herbage, expanding their wings in the blaze of the 

 sun. 



The eggs, so far as known, are truncate pyriform in shape, scarcely 

 higher than broad, with slight vertical ribs on the upper half and indented 

 like a thimble-head below. The caterpillars resemble a miniature Satur- 

 uia mala, with their bristling fleshy tubercles, and are of a dark or 

 violet hue, more or less striped with paler, narrow, longitudinal lines. 

 The chrysalids are but slightly angulated, though StolF represents a South 

 American species with rather prominent tubercles and ocellar prominences ; 

 the abdomen is marked by a distinct, thougli slight, transverse ridge on 

 the fourth abdominal segment, surmounted by the tubercles common to 

 the dorsum of the abdomen. 



EXCURSUS XIX.— THE BUTTERFLY FAUNA OF THE EAST- 

 ERN UNITED STATES AND ESPECIALLY OF NEW 

 ENGLAND, COMPARED TO THAT OF EUROPE. 



New thoughts are urgent as the growth of wings ; 

 The widening vision is imperious 

 As higher members bursting the worm's sheath. 

 You cannot grovel in the worm's delights : 

 You must take wingc^d pleasures, wiug6d pains. 

 Gkorge 'E.i.iOT.— Spanish Gypsy. 



If we go outside the United States to look for a butterfly fauna most 

 closely resembling our own, we shall certainly have to seek it in the north 

 temperate zone ; and shall find there indeed no great difference, viewing 

 the matter in a broad light ; no such differences for instance, as one 

 would find in going to a tropical country. But the resemblance, when we 

 come to the details, and indeed in some of its wider features, is not so 

 strong as is generally believed. 



