ii6 LEPIDOPTERA. 



curious to notice that all those found in the South Pacific 

 were, as also are those which have reached this country, of 

 the North American type. The Central American form, or 

 variety Lcucogi/nc, in which the marginal dots are suffused or 

 obliterated, and the female often very pale ; and the variety 

 from Buenos Ayres, known as Erippus — smaller, with brown 

 uervures and large marginal spots — do not appear to be 

 stirred by the same migratory impulse. The recent history 

 of this insect seems to be unique in entomological annals. 

 Some slight parallel may perhaps be suggested by the 

 instances in which the stragglers of some swarm of locusts 

 have reached these islands, but there is nothing to indicate, 

 in their case, a journey greater than that from the North of 

 Africa, while Danais arcliip)pius can only have reached us, 

 apparently, directly from the other side of the Atlantic, 

 whether by its own extraordinary power of flight and at a 

 considei'able elevation ; or by the help of crossing vessels ; 

 or by a longer route, with shorter sea passage, from Brazil, 

 by the Cape de Verde Islands, the Canaries, and the south- 

 east of Europe. But the latter hypotliesis is rendered im- 

 probable by the fact that the North American form, only, 

 has been found to have so migrated; while the former is 

 greatly strengthened by the evidence of its enormous sweep 

 of migration through the whole Pacific Ocean to New Zealand 

 and Tasmania. 



Family 7. NYMPHALID^. 



Antennse moderately slender, with stout, elongated, or 

 spoon-shaped clubs. First pair of legs imperfect in both 

 sexes, generally broadly fringed with hairs. Wings emargi- 

 nate, rounded, or with blunt projections; robust, and usually 

 brightly coloured. Hind wings with a hollow for the recep- 

 tion of the abdomen. 



Larv^ cylindrical, spiny. 



